What did you do to your Yamaha today?

The one thing I noticed on my 750 is it only takes just a slight bit of the floats being off to make a really big difference in the idle quality and ease of tuning. I devised a float gauge using 4 short lengths of plastic tubing and secured them upward so they all matched in positions then on a verified level surface opened them all and lets things settle for a minute. It took some time to get the floats exactly right but once I did everything else fell into place. All of my carbs run 2 1/4 turns out using matching (new) fine thread needles backed with new O-rings on the stems. I had one early problem with an O-ring that balled up and after replacement everything was lightly lubed with silicone grease, never had a problem since.

So I have to ask how are the gaskets behind the intake boots to the engine itself? I trust they're verified to seal well and the boot isn't cracked somewhere out of sight? How about the shaft seals and bushings and that all-mighty interface between the lower YICS chamber and cylinder head? When I cleaned out my lower chamber with spray I noticed a little weeping around the #1 feeder port but chose to leave it until I pull the head for a valve job this winter. I can see a leak here causing some big headaches.

Anyway just some suggestions, please let us know how it goes.
Brett

 

Back in April I posted a picture of how I did my float levels. Pretty much the same only I did them one at a time and clamped the rack in a vise, checking with a level. It was an annoying task, but I did get them all to the magic 3 millimeters.

Two of my carbs are at about 1 1/2, the third a bit over 2, and the fourth a bit over 1. These are close to the settings I recorded when I removed the EPA plugs and needles. My carbs are the coarse-thread style.

It's a 1980 model, so no YICS chamber to fool around with . Also no low-end torque .

I inspected the rubber intake manifolds, and while there is some superficial cracking around the vacuum-connection nipples there do not seem to be any leaks. Is there anything I can to to repair these and preserve the rubber from cracking more meaningfully?

Today I took the bike for a little 10-mile warm-up ride, during which I got to see a big mess being cleaned up after a semi loaded with gravel took a corner too fast. They had the truck up on its wheels by the time I got there, and there were a couple end loaders scooping up the gravel from the ditch alongside the road. Interesting...

Anyway, when I got back I tried re-synching the carbs, and here I noticed something odd. A while back I modified the fuel valve to be an OFF-ON-RES style, which involved disconnecting and plugging the vacuum line. When I went to hook up my vacuum gauge on #3, I noticed the hose seemed an awfully loose fit on the little nipple on the manifold. Hmm... I dug around in the garage, found some 1/8" vacuum line I had bought to repair the EVAP system on my Himalayan (wrong size; that thing takes 3/16" or something) and found that was a nice tight fit on the manifold nipple. Could there have been a small leak on this (un-clamped) connection?

So I re-synched the carbs. #4 did require some adjusting to match up to #1; #2 was fine; #1 had to go in a little as well. The differences were about 1 to 1.5" of vacuum, which is actually a lot as the four finally synched at 6.5" vacuum at 1100 rpm. It seemed much better so I took it for a 60-mile ride. Almost immediately noticed I had compression braking when I released the throttle, something that had been sadly lacking before. It also idled well at stoplights; the longest one was about a minute. I did notice that it dropped to about 1500, sat there for a few seconds and then settled in at 1100. Not perfect, but greatly improved. If the bike was 90% of the way to "spot on" a week ago, it is now 95% of the way. It would still benefit from fine-tuning the mixture screws, I suspect.

It did develop a different annoyance: warm starting is now trickier. Could just be that I need to learn the proper technique, but after my ice cream stop (about 15 minutes in the middle of the ride) it caught briefly and then acted like it was flooded, requiring full throttle and a few seconds of cranking to start. No big clouds of smoke, though, so not "flooded" in the traditional sense.

When I got home I noticed there is a bit of oil on top of the engine under the alternator. Not entirely sure where it's coming from, but I cleaned it up and perhaps it will tell me where that leak is...

 

Oh the joys of owning a classic bike... well at least it's not a british leaker, don't get me wrong I grew up on the back of my dads '76 Triumph Bonneville 750 of which he still has and with 27,000 on the clock there's not a drop but we all know how some of those and the American brands like to leave their mark. He takes meticulous care of this machine and it still looks great.

Intake boots.
I recently retired from a plastics injection molding company and have worked with many of the compounds both soft & hard, they made the intake boots for Kawasaki America and Polaris and what I can tell you is there's no way to "preserve" the intake boots long term. The plasticizer itself is ethanol soluble and it also slowly evaporates over time so you get the heating & cooling cycles that bring on the cracking as the lighter compounds evaporate. I forget the name of the base material used for the Kawasaki and Polaris boots but it hardens over time in the presence of hydrocarbons be it gasoline, oil ect so couple that with the high frequency vibration of the inline-4 running 5000 RPM there's a lot of energy being dissipated across them and they're going to stress crack.

Consider just how small the cylinder is and the overall air/fuel volume at each intake stroke running at idle it doesn't take much of a leak to dilute and upset this. Throttle shaft leaks, a slight crack that opens just a hair during the intake stroke itself in the boot plus the tiny little bit that might make its way down the intake valve guide is plenty to throw things off for a cylinder that's slightly larger than a small lawn mower engine.
An issue I had early on was one of the enrichment needles was hanging up slightly causing all kinds of weirdness and I discovered it by accident bumping it on its top while adjusting the balance screws. Somehow one of the lifting fingers got bent when I pulled the rack down and I never gave it a thought, just one of those things.

So my last carb balance brought them all to exactly the same vacuum and turns out on the pilot screws, I double checked my gauges against a real mercury column and everything was dead even so it's achievable but believe me it takes time. I mean a lot of time... like a full case of beer time then it will be off again when sober enough to ride. Okay so I judge the job by the number of 2-liter jugs of Mtn Dew it will take to complete, from starting point benchtop to finished and floats leveled it took me just over 12 hours and this included pushing fine little wires through the passages while wet with carburetor cleaner. A full 2-liter

So don't mind me asking the obvious but how is the compression? How about any leakage passed the valve seats? I used a rubber tipped blow gun in my spark plug holes at compression TDC to check them by ear and found nothing (knock on wood) and only a slight hisssss..... from the little that gets past the ring gaps. My bike came to me in a number of milk jug baskets with the usual disclaimer of "Some Assembly Required" so I did have an opportunity to do some in-depth checking & inspecting, with 36021 miles on the clock when I bought it everything was in grade-8 shape except the carburetors. They looked like a meal I left in the oven too long, like far after the smoke alarm battery went dead. My first attempt despite reading the entire Church Of Clean page got the engine to run but not very well, overall it took me four tries to get everything on the money and now it starts easy hot and cold with only a slight tug of the lever to keep it running on a cold start. A little heat on the jugs and I'm off pulling the lever back to center once I'm moving.

 

What did my Yamaha do to me today, you ask? Well, broke the clutch cable. Needless to say I stalled at the next light, in 1st. Couldn't pull the cable with the tool pouch pliers, so the only way to get going was to start it in 2nd. Wheeeee!

 

Yeah... know this one well so now I keep a spare coiled up under the seat. Sure beats the alternative.

Looking at the possibility of pulling out my motor this winter and doing a valve job & timing chain at the minimum with the possibility of a re-ring or the full-meal-deal rebuild depending on how the funds go. I have a long time friend who is a tool & die maker with some 60+ years of experience of building race car engines who's willing to do the head so once the snow flies things will start to happen.

 

You can take the head off the engine in the frame. But if you fit an endless chain you will be splitting the cases anyway. Change the alternator/starter chain guide too and check your starter clutch. Its not difficult just takes a bit of time.

 

What did I do to my Yamaha today? Rode it 265 miles to the Mississippi River and back. It was a sunny day with temperatures in the low 80s, and in late October I am not going to pass up such an opportunity!



740 miles a couple weeks ago, when I rode to Iowa and Wisconsin. 170 miles on Saturday. 265 miles today. For a bike I was talking about selling, I'm sure riding it a lot...

I have to do something about the kickstand, though... it takes a lot of work to push it down. Comes up easily enough, but getting it down is hard. Doesn't help that my left knee is three weeks from being replaced...

 

I did a 125 mile trip today just up to Moose Lake and back to check out the fall colors... all the trees are bare. Oh well at 76F I wasn't going to sit on my fat... backside and filled the tank. Perfect afternoon for what might be the last nice ride for the year,

 

My last ride of the year will be sometime before November 11, when the knee gets replaced. I still have to stabilize the fuel in three bikes, change the Yam's oil (might do that today, as it's supposed to be 71º and I hear the ice cream shop calling), and possibly trade the 411cc Himalayan for a new 450cc model... assuming the new bikes ever actually arrive here.

 

So today... went for a short (~60-70 mile) round trip to the ice cream shop, came back and changed oil. I am impressed by how easy it is to change oil on this bike, especially compared with my Harley (hard-to-reach drain plug, spin-on filter mounted sideways above the voltage regulator and motor mount) and Himalayan (requires using bent-up license plates to keep oil from dribbling into the bash plate). Somebody at Yamaha apparently gave some thought to changing the oil. Nice.

 

I managed to get another 30 miles on today before the weather turned sour, cold front blew in and with it a good sprinkle that made the roads slick from the accumulated crud & oil drippings. We've not had any significant rain since early September and it's bone dry and our temperature dropped 24F in just 45 minutes and is now sitting at 41F as of this post. Gotta tell ya I'm dreading winter this year.

 

I hear ya, @Brhatweed. Sad, sad, sad, time of year. Put away the bikes and dig out the snowblower. Sucks.

 

We'll see how things go, the head will be in Howard Lake after the first snow for a valve job and I might do rings as well but it's going to be a long winter with the Toro regardless. I'm a rural carrier that runs a 145 mile route on municipal roads so I really dread the snow & ice.

 

Today I took my XJ for a 40 or so mile ride, put stabilizer in at the gas stop, and parked it until sometime in the spring. Two weeks from a knee replacement, so I'm getting things lined up for a multi-month nap. Later this week the Himalayan will get its end of season oil change and be put away until spring... or until I trade it in on the new liquid-cooled model. The Harley will probably get its last ride of the year on Friday. Sigh. Winter...

 

Snowglobe SECA

 

Now that the majority of the snow has melted from the seat I did get a few miles on today, officially we picked up 6.3 inches of slop. Bike really didn't want to crank this afternoon, running 20W50 conventional in the box now and it was 48F... honestly I didn't want to crank this afternoon. Might get a few more rides in this week, possibly early next week but a spot in the garage has been made and the battery tender is plugged in and waiting. Really don't want to hang up the helmet.

 

Well the end of the bike season has arrived here. Pulled the tank and drained it out then sprayed the interior with WD-40 and closed the cap, drained the carb bowls leaving the screws out for the winter and brought the battery in to hibernate on a 5ma charger. 7,798 miles this year on the same rear tire, still shy of the wear bars but I most likely will replace it next year anyway... lets see how the economy goes. Might do some work on it during the winter but bike funds are a little thin at the moment, right now it's tucked away in the garage on the center stand next to the snow blower.

 

Sounds like a great season!
Road today in southern New Hampshire but not many days left.
Already starting a list of upgrades for spring time.
List includes but not limited to
Replace front brake caliper,master cylinder and line,
Clutch,
Fork seals
Change gear lube,
And a few more I am sure.
Have a safe winter
Paul

 

Hey Brahtweed
Not sure how to get the word out to everyone on this site but I just ran across a Craigslist post today for a 82 xj550 in Marlborough Massachusetts. Looks complete the guy wants 100.00 or it going to scrap if no one grabs it
Thanks Paul

 

Post the link.

 

Here is the Craigslist ID 7800037940
Type in search and it will pop up

 

https://worcester.craigslist.org/mpo/d/marlborough-82-yamaha-550-maxim/7800037940.html

 

A minor oil leak brought on the need for a periodic valve clearance check followed by new cam cover gasket and bolt seals. I live in South Florida so there was a nice ride, too, to check my work. All was well.

 

Finished cleaning, replacing all the rubber and incorrect parts, and reassembling the carbs for the XJ900. Still need to align them, check the fuel levels, install, and sync.

 

In the process of rebuilding the quad downdraft mikunis on my vmax. They are a right pain to set the float levels - you have to do them individually because the float cambers face inwards - even then it's a bit of a faff. Maybe I'll make a jig to clamp the top face to the underside of a level surface - holding the carb whilst flushing fuel out and holding the clear tube needs three hands. One thing I did find helped, I marked the setting on the body with pencil before testing. And after the first one was spot on I found a 7mm drill shank between the main jet and the float was a good starting point for bench setting.
Other issues was a lack of rubber bungs for the jet holders - despite a uk supplier sending me a kit with them supposedly in there, ended up making my own from ptfe rod.

 

Replaced my rear brake shoes today. I neglected to read the safety-critical thread while riding all summer, so I was mortified when I realized my drum could lock up at any time. My bike came to me this year with only 3900 miles on it, so the brake shoes were probably the original 1981 units!

When took off the rear wheel, there was no sign of delamination, but there was SO MUCH dust. The shoes seemed pretty crusty and old, so I was happy to replace them. I was told to expect worse braking performance for a bit, but it actually seems better. Old shoes must have been in pretty bad shape.

 

Not much in the way for ventilation on the rear drums for these, mine did have a delamination and it got caught up and dragged by the rust & dust inside on the highway. No damage but it made quite the mess.

 

So, learned my oil like works on Saturday.
I have been laxed in checking oil window it seems. I put 800 miles on the bike this summer (I keep it at another location where my boat is).
Took off out of the neighborhood and the oil light came on). I stopped to turn around and it then went off. I took it slow to the house, Put it on the center stand and saw no oil in the window. Took another bike out, came back and a little sliver of oil was showing near the bottom.
Put in about 1/4 quart I think it was , not sure to bring it back to 75% of the window. Took it out later that day for an hour and then again on Sunday for 60 mile ride to and from a bike meet up and all was good.
Nice to at least know the oil switch works
Bike has been a dream all summer. But I'm going to be selling it Making room for something else. Really wish I could sell to either someone I know or at least someone who will appreciate the work I went through. I'm keeping my 78 XS650 though as my vintage UJM.

 

Project loading, will update tomorrow or thanksgiving day..

yes my center stand is absent, no I don’t have a good excuse as to why

 

Ya know if you need some extra space on that top shelf I could put some of that R22 to good use

I do like the bike and it looks like you have a great assistant.

 

Only a few months away.

 

Update to my last post, my helper was helping mom with food before guests today
New aluminum swing arm from Japan, and some BEET side covers!! I’ve waited about 3 years to jump on parts like these

For some reason, Japanese sellers only recently started making these parts available in the us for a reasonable price, I was seeing these side covers listed for thousands the swing arm for about a grand of usd on other sketchy sites.. no way jose.
I picked up both for under 500 shipped from Tokyo on eBay about 6 days ago!
Cutting weight was not my goal, most of my bike is functional or cool aftermarket parts, or parts from other Yamahas, or European XJ400’s, 550’s, and all the 600’s. These are period appropriate Japanese parts and they make me happy.

next up is some Italian rear sets, a “proper” seat, a motogadget mini, completely redo the wiring (when I originally did it I was in a hurry, so it’s routed weird and want to make it entirely new), and a detail polish.
By then it’ll be spring, maybe.

 

I’ve got quite a bit! I will go through it before the end of next summer, though. I work residential and everyone always wants 1 more year with their system, haha

 

Oh I get that one! I have two old packaged relics on the rooftop that seem to have a need for constant attention.

I'm really diggin' the ride, did you just clear coat the raw tank or is that a silver?

 

Is your assistant checking your welding on that frame loop? Hope he passed it . Bike looks great.

 

Got a lead on a 1983 XJ900 motor sans frame but before I jump on it gotta ask how similar is it to the 750 motor in terms of mounting and what's the reputation of these? Front was folded in so the motor was carefully saved leaving everything else behind, I like the 750 motor but being the impatient Norwegian that I am a few more ponies under the saddle would do me well. Information Overload says anything is possible but I'd like to hear from the hands of experience. $450 is the asking on the motor and it has a few zillion miles on it.
Thanks in advance.

 

This should help you @Brhatweed

https://xjbikes.com/forums/threads/900-engine-in-750-frame.29398/

 

physical dimensions of the 900 are the same as the 750 except the head.
The 900 has cam supports on the end of the cam shafts which makes the head wider.
That shouldn't present any problems.
The cylinder blocks are very close in height, not sure if the head is any taller.
You'll want to use the 900's Mikuni carbs so connecting your 750 Seca rubbers to the airbox is a guess if they fit.
Maybe see how close the 900 rubbers are to the 750.
You'll need to move the wires around on the the plugs into the TCI, I don't expect they're in the same configuration.

 

Thanks for the pointer on the conversion, the project funds are a little tight this year so it might have to wait, I've also given thought to just doing a rebuild of the 750 but that too demands some coin. I went to look at the motor this morning and found the #2 rod hanging out the bottom front so it's out of the picture. I suggested parting it out on the 'bay but he's determined to sell it as a whole, might need fewer beers to change his mind. Overall it's in sad shape, no carbs and the top cover is cracked from the original impact.

passed up for sanity...

Maybe this Trump economy will pick up and someone will need an unemployed radioman.

 

And as you said, it had some miles on it so maybe not a good candidate anyway.
Putting a big bore on your 750 would be a great project.
I have 68.5mm ready to go on my 650T using parts from Germany.
58L motors are common there and shipping not bad either when its just an aluminum block.

 

Found the info on that... hmmm $$$$. Looks like it's going to stay a real 750 for now with a new set of rings and valve job. Mine does have a fair amount of blow-by judging by the puffs coming from the breather at idle and I've had past experiences with rings losing tension over time just from age so this might brings everything back to where they should be. Despite the saddle the SECA has to be one of my all time favs and I've had a lot of machines over the years going back to the mid-80s with a Honda 175 scrambler, I was much lighter then. In all honesty I don't want to wreck a good thing and in the 8,000-some miles I put on the bike this past year I can't complain, only one partial failure with the TCI that was solved with new capacitors and resoldering the internals. I've replaced the fork seals, tapped & recoiled the cover bolt holes and gone thru the carbs several times on top of the other maintenance. If that 900 was serviceable that could have been addressed over the winter months leaving the 750 intact.

 

82 XJ650 maxim
New valve cover gasket from Len @xj4ever installed.
These areas, see pencil tip in photos, look odd without any gasket material between valve cover and cylinder head. They’re on the intake side of the cover between spark plugs for 1&2 and 3&4.
Is this normal?
Thanks

 

Sometimes the gaskets are made without that little bit over the unused bolt bosses. If the gasket didn't roll up or pull out of the groove it would be good to go.

 

If its not leaking it will be fine. Ask Len he will know for sure.

 

Got the green light from Len, all good thanks!
Haven’t started it up yet, need to get carb back on after rebuild/benchsych/wet float height setting.

 

Glad to see the site is back up! Thanks @SnoSheriff

A couple days ago I finally got around to installing a garage heater after years of whining about working in the cold. (and therefore, avoiding it)

Today I celebrated by finishing up the rear brakes on the XJ900. New hose, fluid flush, and bleeding.

It was a pleasure to work in a balmy 70F garage. Maybe I'll actually get some things done this winter for a change...

 

Little Christmas present to myself:



After reading the horror-story warnings about how time affects glued-on brake linings, I treated myself to replacements for my '80 Maxim. Now, I'm six weeks into recovery from knee replacement, so there's no way I could pull the wheel off the bike to check fit, but fortunately I have a complete spare wheel set and brake panel, so I popped 'em in and checked.

Since I have pretty much decided to keep this bike at least another year (so I can roll the odo to 12345.6 and trip meter to 789.0; when you have the chance to do something silly like that, you gotta take it), I have to deal with the interaction between the rear brake lever and my lowered footpegs. With the lowered pegs in place, the lever bangs into the pegs and leaves the pedal an inch or so lower than I'd like. I could just stick a hockey puck to the top of the pedal to raise it (rather like how I am going to bolt a hockey puck to my new Himalayan's side stand so the bike stands more upright), or I could get ambitious and see if I can use the induction heater to soften the lever and give it more of a bend. And yes, I have a spare lever as well...

 

I completed (mostly) a front brake overhaul today. The process started a month ago when I ordered an MC rebuild kit and a caliper seals kit from Len. I thought the caliper piston would be fine, but when I took it out, there was pitting on the interior surface. Soooooo, one new piston later, and I finally had everything I needed.

Rebuilt the caliper, rebuilt the MC, changed the brake pads out for sintered metal replacements, and replaced the original (marked 1980, yikes!) brake lines with stainless steel braided hoses. Took her for a test ride today, and the handle was still a little squishy. I got plenty of braking power when squeezing the handle all the way, but it didn’t seem to actuate until fairly far through its travel. I guess there’s still some air in there that I wasn’t able to bleed out.

Still, feel much more secure with all those seals replaced! Back to bleeding the air out tomorrow.

 

Came across my plugs from last summer and gave them a good lookin' over again and thought maybe I should add a bung to the header collector and use my wideband O2 to dial this in... header is off and in the trunk of my car for the trip out to Seleen Engineering in Howard Lake for a date with the TIG welder.