1981 XJ650 Midnight Maxim Restore - (Picture Heavy)

Nice looking shop. I'd love to have that much space to allocate to my motorcycle project(s), I mostly have to plan to finish a project in a weekend.

I'd like to build a small workshop next to my house with enough room to work on my bike or any other projects on a longer term basis and not worry about parts laying around for long periods.

Nice work on your Maxim by the way. Thanks for the pix.

 

OK, so we're looking at a 20K mile bike that had "starting and running issues."

Nowhere in your "done" or "to-do" lists do I see "check and adjust valve clearances."

Just a reminder: The valves have to be in spec before you try to vacuum sync those freshly-rebuilt carbs. And be sure you "wet-set" the floats.

 

Sorry, I forgot to mention that. They were checked and all within spec this past Spring. That will be on the list of things to do when I put it all back together and start tuning the engine.

 

Cleaned the engine and transmission today. Took advantage of the unusually warm 60 degree weather to power wash and scrub the engine with 409 and a toothbrush. Okay, so that is a lie - it took FOUR toothbrushes to get MOST the dirt.

While I had the engine out, I took off the starter motor and checked the brushes. They seem to be in good shape. The springs are holding together, the brushes are still in decent shape, the seals AND gears all are in great shape! Put it back together, cleaned under the motor (and the motor housing), and mounted it back on the transmission (with some loc-tite, of course!).

In other news Merry Christmas and Happy New Year to everyone (or Happy Holidays in general). I hope everyone had a great holiday and enjoyed the time with their families. I was fortunate enough to get a new camera, which means I get to treat you all to some new pictures!

Before I get to some posted pictures, I just wanted to let everyone know that you can view the progress on the bike with pic-by-pic comments where applicable on my Picasa/Google+ album here.

Now here are some before and after pictures for you guys! (Sorry about some of the angles not matching, I didn't really plan this out as well as I should have)









Any input on the 'before and after' pictures is welcomed! I decided this was the easiest way to display my progress, and hope that you guys enjoy it. For the original pictures I would HIGHLY recommend viewing the entire album and all my previous posted pictures of the bike at the link above (or here if you missed the link). As always I welcome any and all criticisms and suggestions of my work - I am still learning!

 

Beautiful work, I definitely enjoy the pics. The XJ Midnight is totally an awesome ride - Im glad to hear you're intent on keeping the stock paint job for the most part.

 

So update on the bike. Took a half day at work today go get some quality time in with my beauty (in lieu of a girlfriend, HA! And yes, the bike will always be a mistress of mine).

Today's work consisted of some reassembly - a nice change from prep work, cleaning, stripping paint, sanding, grinding, soaking, priming, and so on. After an almost cull 8 hours of work, she has both her stands (kick and center), an air box, tool compartment, battery holder, left side panel (still saving up for the right one), a beautiful WHOLE grab bar compliments of princealbert3, a smooth sliding steering column and installed forks and triple clamps, and body panels left and right.

If all goes well, my plan moving forward is to paint my freshly primed final drive and drum brake cover and other various parts (mostly front end parts) then touch up the bike as a whole once it is all together.

I decided against replacing the swing arm bearings for now with the unexpectedly high cost of my steering column bearings.

I would have pictures posted today, but I managed to skin the inner side of my left (dominant) thumb and smashed my right hand twice. I will post pictures sometime in the next day or two (assuming my hands haven't severed themselves from my body in an act of self preservation by that point).

 

Progress is REWARDING!

So this weekend, after finally finishing almost ALL of my painting, I started reassembly of my beloved XJ.

First off, I have to thank in detal LETitRIDEparts for hooking me up with a replacement tail light assembly, rear turn signals, instrument cluster, carburetor rack, airbox-to-carb boots, carb-to-engine boots, left and right body panels AND a new seat - all of which can be seen below). For anyone interested in parts from his post in the Buy/Sell/Trade section, I HIGHLY recommend him, he was friendly and accurate in parts representation.


So after the four-and-a-half hour round trip to pick up my parts from LETitRIDEparts, Saturday's work was wonderful. It started with finishing baking the paint on some of the parts I had painted - specifically the fenders, body panels, various control cable mounts, signal housings, and body panels. Sadly, I decided to stick my fresh new body panels in the oven at 200 deg F (93 deg C) and managed to melt a lovely indent into each, which I was only partially able to recover. This error can be seen later on in the pictures if you look closely, and this was a devastating mistake on my part - I haven't stopped kicking myself for it.

In addition to painting some final body parts, I FINALLY got a chance (after 12 weeks and counting) to start reassembly.

Before we go on, I feel it is important to recall the picture of the bike less than a week after I purchased it - seat torn, lacking a battery and mirrors, shocks and tires in dire need of replacement, barely able to start with quickstart, only the right side turn signals working... the list goes on but that is all beside the point right now. I feel it is only necessary we review that day and the condition the bike was in at the time:


So now with that out of the way, let's return to the topic of this post: this weekend and today.

Reassembly has begun! Saturday was a long day for me - up at 9am and in the garage by 10, on the road at 11 and back by 4, working on the bike until 11pm. What all did I accomplish in this long day? First off, a decent amount of polishing and buffing restored some beautiful parts purchased from LETitRIDEparts (the tail light and seat), baking on the paint on other parts, reassembly of the frame to the front end (minus the handlebars and above), reattaching all wiring and body panels, installing the engine and attaching my newly acquired steering column reflectors (thanks again LET itRIDEparts).

And now for some pictures from Saturday's work:






I do have to say (and definitely not tooting my own horn - PLENTY of mistakes in the paint) that she is coming along BEAUTIFULLY.

As mentioned above, I have a NUMBER of mistakes in my work. First off, there is a section at the back of the final drive that is primed but NOT painted - and it is already on the bike. That is going to be a problem, and will get some touch-up paint once I get a chance to mask off the rest of the bike and ride her to heat the final drive up enough to cure the paint. Also, re-inserting the engine has led to a number of chips in the frame paint. I have to touch up these parts as well, which will also require masking and taping.

So on a mechanical side of things, during my engine thorough cleaning, I disassembled and reassembled the starter motor to ensure the brushes and other internal parts were in good working order. This included greasing the planetary gears and confirmed the brushes are in great shape. I stupidly did NOT consult the manual before doing this, so when I had the bike wired up and did a test engine turn-over, my starter ran backwards. Turns out it was a simple fix: I had the brush plate in the wrong orientation. Funny how something so seemingly insignificant can make such a large difference. Ten minutes of troubleshooting and voila! Engine turned over beautifully.

Sunday was spent mostly cleaning up and breaking down my smaller paint booth. I also took advantage of the booth to do a lot of the gold accent work (carb hats, headlight housing ring, air box covers) and I've got to say I am VERY pleased with the result. This is a DIRECT cause of my now impending desire to repaint the wheels and finish the rest of the gold accent work.

Sunday also resulted in assembly of the handlebar assembly and attaching the swing arm and rear wheel. I have to take a moment to note my frustration at mating the swing arm and drive shaft to the transmission. It took probably four different attempts at driveshaft, universal joint, swing-arm, and suspension arrangements before success was finally achieved (a note to anyone else looking at doing this: the easiest way is to assemble the swing arm with drive shaft, universal joint, AND boot attached then mount this to the swing arm bearings BEFORE you bolt the universal joint to the transmission. THEN attach the suspension, bolt the universal joint to the transmission drive shaft, place the boot around the transmission and FINALLY attach the rear wheel).

I do not have any pictures of the completed work after Sunday, but today resulted in the baking in of the paint on the carb hats, headlight ring, and air box body panels AND attaching them to the bike. Today also resulted in the thorough dis-assembly and cleaning of all the brass parts from BOTH carburetor racks AND the mounting of the highway bars, light mounting ring, and airbox covers. This I DO have pictures of, as you can see below:







I decided intentionally to NOT repaint the majority of the engine, though the side panels will ALL be repainted with black and gold accent as appropriate. I also plan on pulling the grab bar and painting that gold to match the rest of the fresh paint.

Yes, I do not have a gas cap on the bike - I made the mistake of soaking the entire assembly in a rust-removing solution and corroded the hell out of the internal components so that it now will not disengage even with the key inserted. Any input on how to fix this major blunder would be greatly appreciated.

I am also aware that my tank badges are mismatched - debating on going chrome or gold on them. Feel free to give me your opinions and advice.

If you take a good look at the right side of the tank I decided to just fill the dent with Bondo. It turned out pretty well for a novice job at home. Up close you can make out a few rough patches, but it still looks a LOT better than when I bought it.

You may also notice that I have only ONE highway peg installed. The right side peg just wouldn't tighten enough to prevent twisting on the highway bar. I think this may be due in part to the allen head stripping out some on one of the bolts for the right side - I shall be picking up two new ones to guarantee a snug fit before installing the right peg.

The paint looks great but can definitely use a final polish and wax treatment. I'm waiting on the bike to be done before going about the final steps to make her shine.

More to come when more work has been completed (or unless there are requests for any additional pictures of close-ups). Thanks again to everyone for watching, for your support and for the vast knowledge you have so freely shared on this amazing website! Also thanks to Chacal for the great response time and availability of parts needed to finalize my project!

 

John I am very jealous of your progress. I havn't really many any on mine. Its been sitting unassembled for the last month. I have done some painting but i ran out and i have to get out of town to get more. Gotta get on it!

 

Thanks. Mine spent a few weeks sitting with no progress for a similar reason:lack of money to buy paint and sharing my work area with two cars and a grill. The payoff in the end is well worth the wait!

 

So progress has picked up in the past two weeks!

Carbs have been repainted, rebuilt, and bench synced. Float levels set on the bench (approximately, I discovered the tutorial on XJ4Ever.com AFTER they were installed so they will be coming off and being double checked)

Also finished nearly all of the paint work except for touch-up work. Ordered my final order to get her back to life from Len - can't wait for those parts to come in including the steel brake lines, tank trim, a new gas cap (which will be keyed to my stock lock thanks to the tutorial on XJ4Ever.com on gas cap rebuilding).

Now some pictures for all to enjoy.

 

Nice work john!!

Tis a shame about the side covers, but keep your eyes open and im sure a set will pop up for a reasonable price im sure.

Looking good!

By the way, what exause pipes are those? I like the look of them!

-Chris

 

Sharp John ... Sharp !

 

Thanks Chris!

I know there is a set on here another member asked me to make an offer on, and I am sure I will be doing that as soon as I figure out if it is in the budget.

The exhaust is the ONLY set you can even find (or so I discovered). It is the MAC 4-into-2 exhaust system for all 650 Maxims.

I do have a few gripes about the kit though. First off, each side is two welded parts, a pair of headers down to a joining member and then the mufflers. This means you can NOT use the OEM exhaust header brackets. Instead they give you these two simple chromed plates to bolt the exhaust on with.. MUCH cheaper looking than Yamaha's OEM brackets.

Secondly there is only ONE bracket built on underneath the left side muffler for a center stand stop, and it does NOT include (or even offer a way to mount) a rubber pad. The kickstand ALWAYS slams into the exhaust when put up unless you guide it up carefully with your foot, and even then it will STILL bounce off the exhaust on a bump or rough terrain.

The center stand stop is only a welded angled section of metal maybe 3/4-inch (2cm) front to back and about 1.25 inch (3cm) across. As I said there is no way to add a rubber stop to it, so like the kickstand you ALWAYS have to baby it up after tipping the bike off the center stand.

Other than that it is a clean fit, nice mount, and quiet exhaust.

 

Looking good man! Nice work all around. I hope to get mine up to that level eventually. Probably be a nice project for next winter.
How she running now that you redid the carbs?

 

Well to answer your question, I have not attempted to start the bike. There is no oil in her and I just finished adjusting my valves and now they are all in spec! Clearances are as follows:

Cyl: 1 | 2 | 3 | 4
In: .127 | .152 | .152 | .127
Out: .178 | .203 | .203 | .203
Shim/in: 265 | 265 | 265 | 260
Shim/Out: 260 | 270 | 250 | Unknown

I don't know the exact measurement of the shim for the cylinder 4 exhaust valve. The shim number is completely worn off the back of the shim, but it is in spec so I decided to leave it alone. I have a few spare shims to compare it to so I can figure out what shim it is.

The first cylinder exhaust valve could probably use a 265 seeing as how it is BARELY a .178 clearance. I can't tell if there is a lip on the edge of my feeler gauge blade or not - the .178mm blade has more resistance than usual but then slides in and moves freely between the shim and cam. The .152mm blade seems to slide in and feels slightly loose.. any input anyone has would be greatly appreciated.

Waiting on a gas cap from Len before I can start tuning the carbs - safety FIRST. Speaking of fuel delivery, I re-coated the interior of the fuel tank, so now I will have a rust-free tank AND a much lower risk of foreign particles from inside the tank making their way into the carbs and mucking them up.

 

An update including today's first ride

So after a couple days delay I have a progress report!

My order from Len came in Friday on time as always and exactly the parts I needed. I also got my side cover from Dave F (hogfiddles).

Over the weekend I had the opportunity to touch up the paint (chips from putting the engine in, painting the new side panel, etc). I also got my new brake lines on and bled, my new gas cap installed and the tank filled, and finished a carb bench sync - float levels, idle adjustments.

Starting led to the discovery that I definitely need a new battery. I did finally get the bike to start, and she sounds like she is running a bit rich. A vacuum sync is still needed - I am trying to find someone local who has a vacuum sync tool and a colortune tool so I can finish tuning her.

Also ran into an issue with starting the bike - she does not want to start on her own. Spark is good (with the assistance of a battery charger/jump assist at 10 amps) and she cranks. Valve clearances are in spec, float levels are in spec (confirmed twice to be sure) but she just doesn't want to fire up. I set a ceramic heater under the engine to try and warm it up some, but the engine still won't start without quick start shot into the vacuum ports.

Once I did get the bike started, the engine wouldn't idle around 1050 rpm. At 2k rpm the engine tends to idle for a second or two then drops down to 1750 rpms and right back up to 2k again. I took her out for a nice ride (the first in four months) and response was sluggish. The exhaust definitely doesn't sound right, yadda yadda. After the bike is warm, she starts back up - but only when the bike is hot (within 10 minutes of stopping after a 20 minute ride).

So tomorrow will result in a new battery and hopefully the acquisition of a vacuum gauge set and colortune spark plug kit. This weekend I should be able to get a better grip on where the bike stands and how she runs.

As always, here are some pictures:


Relocated the control for my heated gloves to the top of the MC:

The new gold tank trim courtesy of Len and XJ4Ever:

Fresh engine side cover paint:

The freshly repainted side panel compliments of Dave F (hogfiddles):

And the original panel that came with the bike for the left side:

Got a bit creative with my camera angles here..

And another creative shot. This side of the tank is where the huge dent was that I had to fill with Bondo. The tank is pretty dirty here from leaning on it, but if you look closely you can see a few spots I didn't sand down enough:

And as always you can all view the full album on Picasa here.

 

Hey John,

Bike is looking REALLY good. I finally got some paint and clear coat for my parts and almost have them all done. After that I can start my reassembly. I have one order coming in from Len right now and one more to make. I need some filters and spark plugs and maybe a new battery. I might try to get those here in Canada for shipping quickness though. Are you planning on trying to get it back to stock with original pipes and such?

 

Bobby,

I considered going back to stock pipes, but for now these ones are staying on the bike. It really hurt having to spend $400 on this set, and I searched for two months straight to find aftermarket ones. I would LOVE to go back to the OEM look of the stock ones, but I am concerned about the reliability and longevity of replacing with a set of used pipes. The alternative is far too pricey for me - I wouldn't know where to find OEM NEW ones and even if I did the pipes would probably cost WAY more than the bike is worth, and they would be way out of budget for me. That being said, if I found a set of exhaust pipes in good shape for cheap, I would absolutely consider jumping on them.

In relation to the pipes, the ones on the bike now are FAR from ideal. The plates that connect the headers to the head are cheap looking and wimpy compared to the stock header clamps. I have been trying to figure out a workaround to mount my stock clamps onto the aftermarket pipes, but that is difficult since the 1+2 and 3+4 headers are welded at their bases.

On a side note, you should start a thread on here for your bike - post up pictures, progress, etc. for your bike and keep it updated. Share with us what you are doing and get feedback on your exact project. Len is great for parts, but a thread opens you up for feedback you didn't expect. I wouldn't have gotten my hands on my replacement side panel after I accidentally baked mine out of shape without this thread, after all!

 

Hey, that cover came out really nice. Can't wait to see it on the bike.

Dave F

 

Hey John,

I do have a thread going for my bike. Its just that progress has been that slow that I havn't had the chance to post anything new in it.

Check it out

http://xjbikes.com/Forums/viewtopic/t=3 ... rt=15.html

 

Oh and for your pipes all you would have to do is find a set of XJ pipes and paint them black. Post something in the sell, swap, trade section. Im sure some one has something they can get rid of. Seeing that I have 2 XJ650s I will have to mix and match the exhaust systems from the 2 to make a complete one. Im not to concerned about them last or not. As long as the parts I use are in good shape. Even if you had to "build" your own that wouldn't be too bad.

 

Ask and here it is:



So today I picked up a new properly sized battery and two sets of spark plugs. I also decided to pull the ones that have been in the bike for a year and examine them. Here is the evidence of the past year's riding, including a run from over the weekend totaling about 45 minutes to an hour on the road:

Order: 1 - 2 - 3 - 4


And label dots below each plug in the following pictures:




The 1 and 2 plugs are roughly the same color, but 3 looks to be running a bit rich and 4 is way lean. Please let me know what your input is on plug color and which seem closest to a proper fuel mixture (if any).

I have TWO new sets (both with gaps properly set) and a new battery installed, so I plan on doing a vacuum sync and heating the engine up with one set. I think I can pull the plugs and get a general idea where the fuel mixtures stand and how the engine performs, then use the second set to do my plug chop. In the end I will have a new set of plugs for use this year AND a backup set / new set for next year. Any input on how effective this method will be?

 

John,

I'll share what I've learned recently... First (and I can rightly hear Fitz now), I assume you've gapped those shims.

Second, I am not sure you can tell what's going on by pulling old plugs -- the colors reflect the last few minutes of their use -- so if you were idleing for an extended period they can be darker or black. Not much use... you want to pull 'em under controlled circumstances.

Therefore, I would leave those old plugs in and go for a 30 minute ride some of it hard... Come home, and while NOT letting it cool, THEN put on the Vac guages of your choice, but heck for like $60 bucks you can get a 4-guage dial set -- Synch all... Then -- Leave the guages on, and mixture tune so they are all in the same relative spot -- I can't coach you on tuning w/out a color tune -- there are other posts about listening carefully and screwing them in then out, etc. listening to the motor change, but I was unable to do the Vulcan Mind Meld with my bike to get inside her head for this method to have worked for me -- I just didn't trust the sounds I was hearing... So, I just bought one color tune... Using Color Tune, find yellow then turn in to find white and set the screw "between" these two points (generally yellow to white occurs within 1 revolution).

Then since you've left the synch guages on - double check -- they may have moved a whisker.

Now, leave those old junk plugs in and put into your pocket your 8 new plugs (2 sets) and your socket wrench and go for another 20 minute or so ride, some of it hard...

Then pull over in your selected safe stretch shut her down and put in the new plugs -- Then using same safe stretch, make several runs and chops starting with "top end" if you safely can (wot, 3rd ok, then chop) -- if not, then do 5.5k chops and do several -- to inspect color -- you will likely see a decent off-white with a hint of brown -- that's good... If not, well you'll have to figure out what to do... here's one: http://www.factorypro.com/tech/carbtune ... nes.html#1. Top end (full throttle / 7.5k to redline

good too -- note nothing new here -- these have been posted before: http://www.johnsmotorcycleparts.com/Kei ... g_tips.htm

Then pull those plugs out and put in the second new set and do several 3k chops... see color... do a 4k chop -- see color -- leave that set in -- go home pull in to garage and do not allow extended idel - shut her down and pull plugs -- inspect -- how do they compare to you chops on the road ? This last will give an indication of very lowest end...

Go from there... there more you "chop and look" the more you learn -- I have done maybe 20 chops to date under various conditions...

HINT: my first few were done with my bike insufficienly warmed up and all bikes run lean(er) when cool and rich(er) when "hotter"

Hope this helps

p.s. O h and put some anti-sieze on those rusty things -- and on the new ones -- makes all the chopping and in and out safer -- don't over tighten just snug is OK -- Chopping is a lot of "in and out and up and down..." you should enjoy

 

I think you have that backwards.....They run richer when cooler, and leaner when hotter.

Dave F

 

My esteemed colleauge from the north, I am sorry to respectfully disagree, but (I believe) you are not correct.

From the tuning articles, and confirming what I've learned through chop and "feel" experience:

Example #1: If the engine has a "wet" rhythmic, soggy area at full throttle / 3k-4k rpm, that gets worse as the engine heats up, lower the fuel level (i.e. too rich) by resetting the float height 1mm greater (if the original was 13mm - go to 14mm). This will lower the fuel level, making full throttle / 2k-3k rpm leaner.

Example #2: If the bike pulls harder at high rpm when cold and less hard when fully warmed up, the main jet is too large.

Example #3: Decide if you are rich or lean. Worse hot: Symptom of rich. Worse cold: Symptom of lean.

Please also reference post -- middle of the page here:

http://www.xjbikes.com/Forums/viewtopic ... tml#312623

p.s. I believe that the reason engines run leaner cold, richer hot is atomization of the fuel... when cold, larger droplets are at play without complete burn, when hot, the fuel more completely atomizes with a more complete (i.e. richer) burn. Blip the throttle within the first 10 seconds of starting -- you'll often get a sudden lean hesitation or lean a backfire

 

Hey, that cover looks good on there! I'd strongly suggest that you keep looking for a good set of the shiney gold airbox covers, and the the shiney gold swingarm pivot covers. But for now, those will do

Dave F

 

I agree with Dave on the shiny parts. Im going to keep mine original until I can find some NOS or like new ones.

 

Been thinking about that actually haha. I did this gold because it was readily available, but the tank trim makes it look dark and dull. I have to fill in the body panels and final drive / brake cover accents gold too still, so there is a good chance that gold tone will change.

Also interested in clarification on the rich / lean fuel mixture topic. I will be tuning today and this weekend so clarification there would be greatly appreciated.

If anyone has a good resource for a walk-through of how to fine tune fuel mixtures at various RPMs I would be interested in that too.

 

Okay so update on getting her started, and it doesn't look good. First off, valve clearances are all in spec, float levels are dead on, idle adjustment screws 2.5 turns out, carbs bench synced, spark plugs new and properly gapped yet the bike won't fire up.

So I pulled out the multimeter and checked the resistance of the coils. Bingo, we have a problem.

Primary resistances all 7-10 ohms.
Secondary all registering around 23 M ohms.

Double checked and confirmed. Confirms 30 year old coils are in need of replacement.

Here is my question now: What are my options for aftermarket coils? I don't mind building a bracket or harness for them, I am just hoping to get the coils SOON and CHEAP, but I don't want to get bargain/used ones that won't last or will kill my TCI.

 

John, see the decisions and procedures I went through here (middle page):
http://xjbikes.com/Forums/viewtopic/t=3 ... art=0.html

Just as an added precaution -- all plugs into tower loaded up w/Dielectric Greas, boots over plugs, then as an added precaution, I zip-tied (tight cinch) the boots to the cables and to tower to create a tight seal.

And in dealing with the horn, here (bottom page):
http://xjbikes.com/Forums/viewtopic/t=3 ... rt=30.html

And, chopping tuning advice I posted prior page here for you.

Hope these help, all worked for me (by the way, before I put in the new coils, bike would not start after a "hose down" wash -- last Sunday, took the bike to a "power-spray" car wash, and shot the entire motor/wheels, everything... to get all of that new brake dust off the inner-2 cylinder heads, and other places deep in the motor. I thought to myself: "Oh boy I'm gonna be stuck here till this all dries out..." -- however, FIRED right up all wet - no hesitation)

 

Since you're going to get new coils, and considering what you've been doing to/for the bike, I'd highly recommend spending the money ( iI know that's not what you want to hear) and get a set of Dyna-Coils. You'll NEVER have trouble with them again, and the ignition will also be much stronger.

You could get a set of known good used coils and use those.....I've never heard of the coils causing the tci to blow. In my experience, blown tci's come from a regulator ceasing to work which causes an overload of electric and burns out the tci as well as other fuses, lights, etc...... My experience is that the coil burns out and you're stuck with a dead coil til you replace it.

Think seriously about the dyna coils.

Dave Fox

 

I was leaning towards the Dyna Coils already. I know Len has them for over $100 cheaper than the OEM ones. Granted there is also the mounting kit, cables, and cable ends that would all be needed but would still be cheaper than OEM coils.

I checked around and cannot find used Dyna Coils anywhere. Len sent me a list of available coils/wires/caps available through him as well as the gaskets I will need to replace the head gasket.

I now have a bit of reading and decision making to do, and I expect I will start taking the engine apart down to the head gasket and do a thorough inspection mechanically of the internal components. I am sure you will be seeing a few more updates and pictures this weekend as I get down through each level of the engine.

Thanks again guys for your help, I probably would not have gotten this far this fast without your help!

 

Gawd, that thing is gorgeous! Nice work, man!

 

Ill have to check but I have a couple of side covers if I have a right one i could sand it down and you can have it (its red) what all exactly do you need because most all of the extra parts I have are already on my bike so I have no use for them. I dont think it has the maxim symbol on it though but the one on my tank is falling off.

 

So today was SUPPOSED to be a motorcycle work day, but in total I only got in about 30 minutes of touch up paint work done on the frame. I got sucked into a family house project for the day, but it is a small price considering I have taken over the garage almost every weekend this year for the work done so far.

I did have a chance to start to sift through the information Len sent me about coils, caps, wires and so on (all 37 pages of the email printed - and damn is it thorough), and I have YET to decide on my exact replacement coil/wire/cap combination.

I also NEED to spend tomorrow tearing into the engine and removing the head so I may thoroughly inspect the valve seats, cylinders, clean up the head for a new gasket, clean up my intake and exhaust manifold mating surfaces, check for timing chain wear and guide wear, and check for any other issues I may run into BEFORE I place my order for parts to Len.

I've wisened up in the sense that I will NOT give an estimated time when I expect to be able to ride because as soon as I say 'Okay, riding tomorrow' I discover a new problem TONIGHT or even worse AS I am getting on the road (or attempting to). At this point I have come this far and only really painted the bike, done some light body work, completed my front brake maintenance, and done some LIGHT upgrades but not touched the engine aside from an oil and filter change. Clearly I should have planned to spend as much time INSIDE the engine as I have spent on things away from it.

On the bright side, since I will have the head off the engine I think this will be a PERFECT opportunity for a fresh coat of paint (I can feel my wallet cringing as my fingers type those 'famous last words').

If there is anything to be taken away from this for anyone else looking to do such a rebuild on a bike that has sat for any length of time it is to make a checklist and NOT ignore any problems you had before. Secondly TAKE YOUR TIME and DO NOT CUT CORNERS as I attempted to with cheap paint and no topcoat on some engine components.

Thanks but thanks to Dave F. I have a side cover already painted and installed to replace the missing one.

 

Not a problem but the funny thing is I didnt realize this thread had 6 pages and I thought we were just on the first still. (facepalm)

 

I might have missed it ... what is the gloss black finish you used on the carbs and have you had fuel on it yet?

 

That black gloss paint is high temp engine ceramic paint I purchased in an aerosol can from Advance Auto Parts. It was a primer and paint that then had to be baked onto the parts.

The carbs were together and in contact with fuel about 2-3 days after the paint was baked on. Keep in mind that the parts (while not being baked or painted) were stored in a non-temperature controlled garage between temperatures of 40-50 degrees F.

Given the conditions above, the paint DID come in direct contact with fuel when one of my carb bowls was not seated properly and leaked fuel. Unfortunately it ran right under the paint and the paint wiped off down to the bare metal.

The carb bodies still look fresh and have not been impacted by the presence of fuel VAPOR, and I did discover that once allowed to dry naturally the paint seemingly re-adhered itself to the metal (though clearly this is NOT a sign of 'fuel proof' paint).

 

Okay so quick update on the progress. My busy weekend gave me only this afternoon to work on the bike. I finally did get through the ignition system options from Len, and settled my mind on the Dyna Coils with all new plugs, wires, and the mounting kit.

I took the head off the bike today and inspected the various components and mating surfaces. Good news is the engine seems to be in good shape. Cam Chain guides are in good shape, cam chain looks to be good, pistons and rings are in good shape, and the carbon buildup on the valves will be easily taken care of once my head gasket kit comes in this week. I may be putting a quick coat of high temp paint on the uppers while I have them off the bike, time will tell if that pans out.

Some pictures of the engine from today's work. Most are from before I started scraping gaskets.

 

Got everything back together and I need some help. First off, let's start with the configuration:

Engine:
New gaskets from the cylinder head up, bolts torqued to spec
Timing dead on, all points match up, double and triple checked
Valve clearances in spec, double checked
Oil level appropriate
Compression readings: 1 + 4 @ 130-133 psi. 2 + 3 @ 118-123 psi.

Carbs:
Thoroughly cleaned, no blocked passages
New gaskets all the way through
Float levels set all at 3mm (checked with clear tube)
Bench sync'ed the butterfly valves
Idle screws set at 2.5 turns out. New washers and o-rings

So here is the deal:
With this setup, the bike will START and run for about a second or two. As soon as I try to give it a little throttle, it dies. Will not start again for at least 10 minutes, and then does the same thing. Idle is smooth until it dies, sounds to be around 1000 rpm, doesn't run long enough to get a good reading on the tach.
Will start with quick start sprayed directly into the vacuum ports on each carb-to-engine boot and will maintain at higher revs.. if I let it drop below 2k then it dies, and back to square zero.
The bike doesn't run long enough to get a good idea of which are firing by exhaust temp when started without assistance. I don't have an IR gauge, so determining pipe temp is difficult if not impossible. All pipes DO get warm by a 'back of the hand' test. Exhaust smells rich, sounds deep and appropriate.

So where do I go from here? Adjust idle adjustments?

I know I need to have it running to do a proper vacuum sync, and I REALLY want to avoid using quick start.

EDIT:
So did some extra testing on my own.. here is where I stand with the bike:

First off, given up ether as a starting agent. Switched to PROPANE gas pumped from a propane torch (NOT ignited, obviously) directly into the intake on the air box to get her started. I read a post on here suggesting propane to determine leaks in the carb-to-engine boots, so I thought it was a safe(r) alternative to quick start, though clearly NOT a long term solution - just for diagnostic purposes.

Moving forward, after the bike is STARTED with the propane, it WILL NOT maintain idle. Throttle must hold the engine over 2000-2500 rpm to keep the bike running, and it STILL dies below 2k after 30 seconds to a minute of revving when allowed to drop below 2k rpm.

Played with the idle adjustment screws. At 2 turns out, no firing. at 2.25 turns to 2.75 turns seemed to be the best result. 3 turns out was no better. Adjustments were done in 1/4 turn increments.

All exhaust headers hot, hard to determine which are hotter (or not), still no IR gauge or other accurate temp gauge. MAC 4-into-2 exhaust joins 1 + 2 before the muffler clamp, and 3 + 4 similarly.

Watching the fuel filter and with two extra sets of hands, confirmed fuel being pulled into the carbs when cranking/running.

Letting the battery charge up some from my starting attempts, will start at my diagnostics again tomorrow (neighbors have middle and elementary school children).

Tomorrow going down to my local Yamaha dealership.. I've spent enough there on tires and various parts, I am going to ask them for advice OR to walk me through final tuning if I can't tackle this tomorrow on my own. Any advice and input before that point is VERY welcome.

 

I'm far from a carb expert but I know a bit and to me at least it sounds like you've got an issue with your enrichment circuit or pilot jets or possibly both. The way you describe it dieing out makes me think it's choking itself to death. Ether or propane will cause it to fire do to the higher volitility of the gas over gasoline. If it where me i'd start with the enrichment circuit.
Hopefully one of the carb guru's will chime in and give you more advice.

 

Okay so update on the bike after today's tuning work.

First off, pulled the carbs off the rack. Redid the bench sync them with 1/4" slips of photo paper. Carb 4 was completely closed, holding 1-3 open and causing high revs.

Pulled the carb hats off. Noticed a few diaphragms were not seated properly. Fixed this issue, double checked my work. Also had the piston on cylinder #3 not returning back to fully closed. Fixed this issue.

Reset the idle adjustment screws to 2 turns out.

Checked the alignment of the carb bodies to each other. All lined up, no issues there.

Carb jets all clear. Only change from stock is the primary air jet was changed from a 195 to a 205 in each carburetor.

Installed the carbs on the bike, began testing again. Bike would not start on its own. Used propane in the airbox, got her started. Running MUCH smoother, still doesn't want to start on its own.

Pulled the plugs after a good 7-8 minutes of idle to check fuel mixture. Plugs 2-4 are a light tan color, 1 is still running lean. Adjusted the idle adjustment screw for 1 and started the bike back up.

Took her for a spin with this configuration. The bike is running with WAY more power than before, at full throttle I had to really hold on. Overall VERY impressed with the power the bike has now, despite not starting.

Pulled the plugs after this and determined fuel mixture under load is lean. Exhaust headers discoloring at the head, plugs all very close to white. Picked up some brass washers #6, put one brass washer shim on each carburetor.

Did not have a chance to get back on the bike and ride after doing the throttle shims. I had two beers while working after my first ride, so safety first!

Tomorrow I plan on draining the remaining gallon and a half or so from the tank and filling with fresh gasoline before I do anymore work trying to get it to start. I suspect this could easily be part of the problem.

 

do what you can to get the carbs synced on the bke.

DaveF

 

John, Sounds positive - Just curious - Wy did you let more air into the mixture with larger main air jets? And how exactly did you "shim " the carbs?

 

dmcoach, I may be wrong, but isn't the pilot air jet the larger of the two? I agree on the size, 195 should be correct for the pilot air jet in stock configuration on an 81 650 Maxim.

 

Dave, I will certainly be doing my best to get the carbs synced on the bike today. Part of my challenge is NOT using a colortune kit right now and this week is going to be 70 F every day, so getting her running and STARTING on her own is definitely a priority.
A friend of mine who used to work in an independent shop servicing older Hondas told me a trick of turning the idle adjustment screws out on each carb until the engine starts to rev highest, then turn DOWN the overall idle adjustment until I get around 1050 revs. I will be attempting this today, results will come when I either am successful or get stumped.

Coach, in response to your first question the 195 air jets ARE stock on the 81 Maxim. The 205's are from an 82 YICS carb rack that I bought as spare parts. That particular air jet and the threading of the idle adjustment screw (fine threads on the 81, course on the 82) are the only difference between the model years as far as I can tell.
The way I shimmed the carbs was to take some thin (.5mm) brass washers I picked up from Lowe's, pull the piston / throttle needle, unscrew the throttle needle from the piston, drop a washer down into the hole where the throttle needle sits, and reassemble the carbs. This gives me just the thickness of the washer difference in the height of the needle in relation to the piston. The package of 12 brass washers was about $1.25 and means I have spare shims if I need to increase the fuel mixture more.

Now it is time to go get started on fine tuning the bike! First going to get some fresh gas for the bike, swap out the old stuff and see if that helps!

 

I hate to ask this, but I've read back through the thread (not super thoroughly, admittedly) and looked at your "done" list and I don't see...

Valve clearances. Are your valves in spec, prior to all this carb fussing?

 

Okay valid point. Let me recap the 'done' list in chronological order:

Tires, front and rear, done December 2010
Front caliper and MC rebuild, pad replacement (front and rear), done Spring 2011
Shocks front and rear, done Summer 2011
New Mac 4-into-2 exhaust system, done Summer 2011
Complete repaint / restore of ALL components including engine, done Winter 2011-2012
New steering column bearings, done February 2012
New seat, done February 2012
Full carburetor overhaul, new fittings, o-rings, seals, thorough cleaning, done February-March 2012
New braided steel brake lines (front), done March 2012
Head Gasket Replacement Kit, done March 2012
Valve clearances, timing, full inspection and all checked out, done March 2012
Fresh oil and filter, done March 2012
Fresh gas cap, tank lining, fuel lines, done March 2012
Carburetor tuning and throttle needle shims (brass, 1/2mm) installed, valves and timing double and triple checked, done THIS WEEKEND, March 10th and 11th 2012


So with that being said, let's get into how she runs, shall we? First off, let's keep in mind that I did NOT have access to a colortune spark plug kit nor do I have access to an EGA or a proper vacuum gauge set. I also had no accurate way of measuring exhaust pressure or temperature - the ONLY tools I used to tune were a few screwdrivers, a spark plug socket, and my hands and ears.

Once I had a decent bench sync completed, reset all idle fuel screws to two turns out, measured and confirmed throttle butterfly valves all set equally, compression test results all within normal range, and she started right up. Running was a bit rough at first. A plug chop showed only cylinder 4 at the proper fuel mixture after initial running. A bit of adjustment by ear and with the assistance of FEELING the exhaust headers and she started sounding MUCH smoother.

A quick side note on HOW I dialed in the fuel mixture and carb balance without the use of gauges or an EGA. To start, the bike WAS stationary, on the center stand with a box fan pointed at the engine head at full power. As the pipes warmed up, I checked them by hand (with the paper towel doubled over as a buffer) to see which pipes got hot quicker.

The basic principle was that under the assumption that with each cylinder was getting the same fuel / air mixture it can be safely assumed that a pipe that heats up quicker implies more airflow into that cylinder. With this basic assumption, I was able to adjust the screws connecting each carb throttle shaft until the engine ran smoothly. At this point I did a plug chop and used the plug color to fine tune the fuel mixture screws.

Needless to say that with this being my first time tuning a carburetor system by ear, but I am fairly certain I nearly nailed it. Improvements since before I started the teardown and rebuild include more power, stable idling, smooth acceleration, no revving up after coming to a stop, no need for quick start or other starting agents, more wholesome sounding exhaust, proper plug chop colors, and a MUCH bigger smile on my face when I get the opportunity to open the throttle.

 

I just acquired an 1982 Yamaha XJ650 which is basically the same bike. This is my first bike an I cant believe how much I learned about it in one day just from this forum post. This was a very enjoyable post and I am sure that I will read it again and again. Thanks for sharing!

 

Everything I posted here was compliments of the forums here. I have an advanced knowledge of auto repair (not certified but going to school for auto work this fall) which helped with the basics, but everything motorcycle specific came exclusively from this forum and the Haines manual (also acquired on this forum in pdf format).

Good luck with your project and I hope to see as much about your bike as you have seen about mine.


On a random side note, tomorrow when I get off work I fully intend to get a few shots of the bike in the sunlight now that the paint is (mostly) done. As everyone here knows you never are 'done' with work, but at this point I can finally proudly ride around on my bike knowing I am on a sound piece of machinery built over three decades ago.