Resurrecting my new XJ700X

Got the second set of carbs today. They look really nice inside and out! I decided to just swap over the carb bodies that I messed up instead of the whole rack, but the carbs got a good cleaning anyway. I bench synced, set the floats, and the bike fired right up.

I still seem to be getting some of the same symptoms, though. The bike will rev from 1500RPM to redline with no hesitation at all, but going from idle (which I set to 1000RPM) to redline makes the bike choke on itself and want to die. It also idles a bit rough for my tastes (almost sounds like it has high lift cams in it). I haven't been able to test the bike out under load as I have my front master cylinder out for a rebuild and it has been raining off and on here.

Any ideas? I have the pilot mixture screws backed out three turns this time (I only had two turns before). I noticed that the carbs I just bought were all set to somewhere between 3-1/2 and 4-1/2 turns out, but who knows if these were set right or not.

 

I couldn't resist - I had to ride the bike around a little bit today. Some thoughts: It's not very fun to ride in its current condition. When leaving from a stop, the bike wants to die on me and did a few times during my brief 15 minute ride. Anything above 1500RPM feels good all the way to redline. When the bike really warmed up, it wouldn't even stay idling for me and would dip below 1000RPM and want to die. I had to give it a little bit of gas in quick spurts to keep it going.

I think I may have found a leak between the carb boot and the cylinder head, but I'm not 100% sure on that yet. I'm going to spray some propane around the suspected area and listen for an increase in engine speed. I'll keep you all posted when I get around to doing that.

 

Pull your plugs now that you rode it around better yet if you can on the way back to the driveway for the last 10-15 seconds or so run the bike at 4500-5000rpm then hit the kill switch and close the throttle and coast in. Let the bike cool and check the plugs. It sounds like you are still rich to me.

 

I was kind of thinking the same thing...glad we're on the same page. Plugs are out and I'll get a picture up as soon as my digital camera gets a charge in it. My impressions are number 1 looks good, 2 and 3 can be leaned out a bit and 4 can be leaned out a lot. I'll let the picture do t he talking as soon as I can get it uploaded.

 

Here are the pictures of the plugs:

 

I don't know if it is just the lighting but 3 looks the best. THey all could use a touch of leaness for me but I like to run on the edge.. Now here is what rick has said over and over!! Turn the screws in just a DEGREE or two at a time No 1/8th, no 1/4 turns very very minuscule amounts at a time then pop them back in do a run in the 4500-5000rpm range cut the engine close the throttle let the bik ecool and recheck. Idling will give false results, hitting the kill and keeping the throttle open to wash the plugs will produce a false result.

 

Yea, may just be the lighting as 1 and 3 look almost nearly identical in person. I'll give them all a touch of leaness, as you put it before I put it and see what that gets me.

 

So I leaned up the pilot screws up a couple of degrees (not turns!). Now the bike won't start at all. It has spark and I assume it's getting fuel as I rode it all around today, but the thing just will not start.

I had a similar issue earlier today when I squirted down the bike a bit with water to get some mud off the front and rear fenders. I've heard these bikes are very sensitive to moisture so I just let it dry out a bit and it fired up a little later. I went to top off the coolant level after I pulled the plugs and a little bit spilled over so I'm thinking it hit some sort of electrical connection that it messing me up now. I swear, this bike is cursed.

Sidenote: I pulled the plug wires to test for spark and I was holding the hard plastic part of the plug boot and cranking over the engine at the same time and I was getting little shocks through the plug boot. Nothing that would knock me out or anything, but you could definitely feel some electricity in there. However, I wasn't getting shocked when the plug boot was installed back into the cylinder head. Either way, probably time for some new boots/wires?

 

Wombat,

On the water sensitivity....supposedly the problem (or one of them) is micro-fractures in the stock OEM ignition coils (sometimes even new ones if you can find them). I've not done this mod (yet) but supposedly you can replace the stock coils with aftermarket Dynacoils though its a tad tricky. See description of the mod at www.maxim-x.com.

 

There is also this repair that I've found and might attempt if this sort of behavior keeps up: http://www.surenet.net/~verhey/x-coil/x-coils.html

 

The "guts" of the spark plug caps come apart.
They unscrew from the ends of the plug wires. It's not a bad idea to cut a little off (don't make them too short) and get a new clean connection (might have been mentioned before)
Pull the caps and unscrew the guts to check for corrosion.
There are some resistor sections above the plug contact screws.
I can't remember what the total resistance of the caps are supposed to be...but you will probably find a bunch of rust in there

A little leaner on a couple, and a good sync, and then put a couple miles on it to burn out the cobwebs.
Mine seems very sensitive to "out of sync" conditions. Even modest adjusting the mixtures requires a re-sync to get back in line.

Have you done a compression check? (can't remember all the checks so far)

 

I have not yet done a compression check as the tester I currently own doesn't seem to want to fit into the spark plug threads on my X. I'm going to borrow my buddy's unit since his came with a lot of little do-dads that might work for my bike.

Took some connectors apart up by the steering column, blew them out with the air hose, applied some di-electric grease into the terminals and the bike fired up. The hesitation is still present, but does seem a little more manageable with the bikes new "leanness." I'll probably take the bike out for another spin tomorrow and recheck the plugs. I still also need to check around the carb boots again to see if I can confirm that the one is leaking. Probably wouldn't hurt to replace the o-rings in there anyway.

 

I'm wondering if that's because the X has 12mm plugs vs 14mm on the other models.

 

Yea, that's exactly why. The tester I have only does 14mm and the next size bigger.

Here is the throttle bog I was talking about earlier. This video was taken at 10:30PM EST. I've since fixed this bog a little bit by leaning out the mixture screws a few more degrees. Seems like the more I do that, the smoother the bike gets. I'll have to take some more recent video of it running.

http://www.youtube.com/watch?v=T045cMvrEmM

 

Sounds about like what mine's doing right now. I had parked the bike (but hadn't run the carbs dry) while I was putting off getting parts from Chacal, including the vented gas cap I needed for the X. Prior to taking the bike offline, I had *just* gotten the thing to idle on its own, with no bogging or hesitation.

I get the parts in, swap the lock cylinder from the old cap, reinstall, tank up, and I get a little bit of bogging at just over 1000, and it won't hold an idle. Subsequent investigation revealed that my #2 seems to be running a wee bit colder than the other three, at least on initial warmup, so I'm wondering if the jet in the float bowl got gummed up. I'm dreading having to pull the carbs yet again, but I'll probably end up doing that after I finally get around to finishing the front brakes on the 750.

 

Care to elaborate on the vented gas cap? Does the X not originally come with one and should have one or were you just replacing it?

Here is a video that I took about 11:10PM EST. As you can see, the hesitation/bogging has eased up a bit, but it's still noticeable if I go from idle to wide open quickly. If I ease on the throttle slowly, there is virtually no hesitation at all. This will definitely make it a lot more enjoyable to ride, that's for sure. But, since I come from a heavy fuel injected background, is this just the nature of carbureted bikes?

http://www.youtube.com/watch?v=wPS6yQCoj7g

 

http://www.xjbikes.com/Forums/viewtopic/t=9616/

Mine is a California model. Apparently didn't come with a vented gas cap, as there's supposed to be some sort of "rollover valve" coming out of the tank and running a hose to an emissions canister located behind the right side cover. As I don't appear to have a California tank, but a gas cap that belongs to one, the tank wasn't being vented. The end result was fuel starvation.

 

The ignition coil repair you point out really shows some ingenuity!! I'm going to have to keep a reference to both of these.

 

A couple days of riding and I'm not real happy with the way the bike is idling/performing down at 1000-1500RPM. It still has a slight hesitation that is a little annoying when the bike is cold and I'm leaving from a stop. The hesitation dies down a bit as the bike warms up, but it's still slightly noticeable. I suspect the throttle shaft seals are leaking as I saw some residue on the outside of a couple carbs around the shaft and it smelled of gasoline. Looks like I need to make another Chacal order

 

I ordered new throttle shaft seals, hex head butterfly screws, and carb boot o-rings from Chacal. I removed the carbs and disassembled the throttle shafts and was surprised to see that the seals were in pretty good shape, but I saw some gasoline leakage on a couple of them so it's better that I replace them with new ones.

I ordered the o-rings for the carb boots just for the heck of it so that I could replace them while I had the carbs off. I'm really happy that I did order them as the ring on the number one cylinder was destroyed. Nearly a quarter of the o-ring was missing and the rest of it was pretty mangled. I'm guessing there was a substantial vacuum leak on that cylinder and I'm hoping it contributed to my throttle hesitation coming off idle.

The parts should hopefully be here early this week and I'll be replacing the seals and o-rings right away and I'll post back here with my results.

 

Ok, hopefully someone replies to this as I seem to be talking to myself lately

So I installed the new butterfly shaft seals and new intake boot o-rings. Applied a small amount of silicon grease to both to ensure a good seal. The bike started right up after I put everything back together and I adjusted the idle screw ever so slightly to get the bike sitting at a rock solid 1000RPM idle. Excited, I drove the thing around for 50 miles, literally. I came back to my shop when the bike started acting up again at idle. I would be sitting at traffic lights and stop signs and the bike dipped below 1000RPM and wanted to sputter and die unless I gave it some gas. A little annoyed, I pulled it back into my shop, pulled the gas tank, attached my new hanging homemade tank and went to work on tuning it.

When I replaced the butterfly shaft seals, I also replaced the mixture screw o-rings with brand new OEM ones. Therefore, I had to reset the bike back to the default settings I.E. no tune. I backed them out 3 full turns, but that didn't seem to be enough. The plugs were a very light brown and the bike died when I gave it any off-throttle gas. I finally got it to a point where the bike idles well and off-idle performance is much better, although still not perfect. The problem is that my screws are anywhere from 3.5-4.75 turns out on each cylinder. The plugs are now a darker brown and the idle performance is much better than it was, but this seems like too many turns. I was under the impression when I went the default 3 turns out, I would have to LEAN the bike out because it would be too rich...quite the opposite for me.

Anyone have any suggestions or ideas? Are that many turns normal or is there something else wrong with my bike?

 

Well I can't help you on this one, but I sure would be interested in hearing a response as I am having a near same situation.

 

A recent, now solved, issue I've had with my 650J involved poor idling/starting, in addition to a dimming headlight at speed. Turns out it was my alternator brushes. After changing them I feel like I have a new bike. She runs great, starts great (with about 1/3rd choke), and is much more peppy. I doubt brushes are your problem, but worth a look.

Keep up with the updates! Good luck!

 

I'd say it is what it is.
Run it. Or "ride it like you stole it" as someone signature states.

I bet it took over 1000 miles for mine to finally "settle in" after it's multi-year rest and stay tuned.

Plug chop, adjust mixture, re-sync, ride for a week, repeat.
Don't worry about how many turns you are out. Worry about what the plugs look like and how fast you leave the traffic behind.

Check your float levels too. The needle valves may have shifted and settled in a bit too. If your lean, that might indicate low float level.

Patience and persistance. I know you just want it to be right, but you just woke it up!

 

Took it for another little joyride thinking things were ironed out a tad more, but the bike dipped below 1000RPM at idle and nearly died on me. Tried to give it some gas and it hesitated the same as it has been doing PRIOR to my adjustments. Ticked off, I rode back home (about 10 miles) and pulled the bike into my shop and what do you know...she idled back at 1000RPM with only a slight hesitation coming off idle, just like it was doing when I made the adjustments.

I dunno...this bike has a mind of its own. I'll do another plug chop tomorrow and try to fine tune it a bit better (I feel like it might be rich). I'll take a picture of the plugs and post it up to see what everyone else thinks. The bike is certainly enjoyable, but I feel like it would be much more enjoyable for me to leave a traffic light smoothly without the hiccup.

 

You might consider bringing up your idle a scooch to the 1050 RPM mark. Might help, might not.

 

Not sure if I can bump the idle up that little. There seems to be quite a dead spot in the idle adjustment screw. I go from around 1000RPM, turn it in, nothing...nothing, bam 2500RPM. I then back it off and it'll come down to 1500RPM and settle down even further around 1000RPM and go back to it's normal business of bogging down and almost dying.



Cylinder 1: 4.25 turns out
Cylinder 2: 4.5 turns out
Cylinder 3: 4.75 turns out
Cylinder 4: 5 turns out

Yea, I know, I shouldn't be talking in "turns" but I'll start tuning in degrees when I can figure out what's going on with this bike. It seems like the carb with the fewest number of turns out is the richest the vice versa.

Oh well, back to tuning.

 

Guess I'll go with the Designer_Mike mentality - it is what it is.

I took all of the spark plug caps apart and nipped off about 1/4" on each plug wire, put some dielectric grease on all contacts, and reassembled. While I had the ignition system partially apart, I checked the coils and plug caps for resistance. I got between 12-13K Ohms on the secondaries of the coils and between 9.2-11K Ohms on three of the four plug caps. The fourth plug cap came out around 18K Ohms and, coincidentally, is the plug cap that has the worst arcing problem when the bike idles. I'm going to chalk this one up as me needing at least one new plug cap, but I'm really stretching my budget on this bike as it is, so I think I might call it for the season and work on the ignition system in the winter.

I'll probably try to fine tune it a little better in the near future. I'd also like to know why my bike still seems lean at 5 turns out, while everyone else is doing their finer adjustments at 2.5-3 turns.

 

If I remember correctly, the plug caps are SUPPOSED to be around 5K ohm.
What did the insided of the caps look like?
The "snap connector" that slips over the top of the spark plug un-screws with a flat blade screw-driver. (make sure it's the right size or you'll strip it)
The snap end is probably corroded a bit, but I believe the part is brass, with a steel snap clip.
Pay attention to the order the parts came out. I believe the next part is the resistor core and then a spring.

Clean the parts up, and measure the resistance of the core.
I have heard others that replaced the "resistance core" with a solid piece of copper or aluminum. IIRC it is 2mm diameter. If you go solid, now you will should have almost zero ohm resistance (which isn't great for the coils in my opinion), but will get more juice to the plugs.

I'm betting that you will find a lot of rust on the resistor core and the spring. The spring also has to conduct the juice to the plugs so it needs to make good contact too.

 

Interesting. I was under the impression that the X plug caps had 10K ohms for resistance, but I could have read that for another bike. I need to get my hands on this XJCD quickly!

I was unaware that you could unscrew the "guts" of the plug caps, but I'll definitely be giving that a shot. Thanks for the tip!

 

I popped off the plug caps on cylinders 1 and 4, since they are reachable with the tank still in place. I wanted to see how hard it would be to take these apart and what I would be in for tomorrow morning. Turns out they're really simple if you keep all the pieces together. So the two caps I removed had ohm readings of 9.8K and 10.2K before I unscrewed them, used some real fine sandpaper on the contacting ends of all internal parts and even used a very small amount of dielectric grease for good measure.

Interesting results. Post ohm readings on those coils were 1250K and 23K, respectively. Hmm. Not good, but lets see how the bike responds to it. I screwed the caps back on and stuck a screwdriver in there and tested the spark. MUCH stronger than before and I don't see any arcing against the valve cover...yet. It normally will only do that when the bike is fairly warm, which I haven't been able to test yet. A little puzzled by the post-fix ohm readings, but the bike doesn't seem to mind. Tomorrow morning, I'm going to pull the tank and take apart all four caps and clean them all up. I'm thinking the grease added a lot of resistance? Perhaps I should clean that all off?

 

Seeing as how dielectric grease is NONconductive, I would imagine that it did add resistance, if you put it between mating surfaces before reassembly.

Maybe I'm missing it, but the service manual on the XJCD doesn't mention plug cap resistance. Hap's site has a "page not ready yet" message for the plug caps, so...

 

I think I'll remove the dielectric grease, then. I love using that stuff on anything electrical. Hell, I would put it on my pancakes if it tasted good, but it doesn't. I know this for a fact.

 

VOID....

 

I MISSED SEEING THE MOST IMPORTANT PART OF ANY CARB REBUILD...

COMPRESSED AIR BLOWED THRU ALL PASSAGES AND JETS....

THEIRS PROBABLY SOME SOLID CRUD IN THERE SOMEPLACE

 

schmucko, these bikes either have 'R' plugs or resister caps, but not both, if you have 'R' caps they shoud be removed before testing.

 

I have been trying to get a handle on this for some time now...

Wombat - do you have the original caps with the orange insulator boots? How do you get at the connector when its buried so deep in those tall caps?

If you read through Chacal's plug cap advice in his parts for sale post
http://xjbikes.com/Forums/viewtopic/t=2 ... t=192.html (scroll way down to coils, plugs etc) it says that the original caps (with the orange insulator boots) were 10k resistance (and insanely expensive at $42/ea) but then he recommends a couple suitable replacements which are only 5k resistance? In addition, HAP talks about the difference between 85 and 86 Max-X w/85 using non-resistor spark plugs and 86 resistor type. What I also wonder is was there a difference in cap resistance between 85 and 85?

Maybe more importantly...does any of this really matter

Chacal...if you're listening could you clarify any of this a little?

 

Here is my take on the whole thing.

Yes, I have the original caps with orange insulator boots. If you work at those orange boots, they WILL come off from the plastic portion of the cap. Then, all you need is an appropriately sized flathead screwdriver to reach down in there and unscrew the visible portion of the plug cap "guts." Out will fall the spark plug snap connector, a piece of I-don't-know-what resistor, a very tiny circular brass/copper ring, and a long spring...and in that order.

So, the difference between the 1985 and the 1986 X plug caps are that piece of I-don't-know-what resistor material. I assume in 1986, they changed that to something else with a much lower resistance, but then required the bikes to use resistor plugs to make up for the lost resistance. In 1985, they simply used that piece of I-don't-know-what resistor as the sole resistance in the ignition system, which is why the 1985's use non-resistor type plugs.

So, if you'd like to replace them with 5K resistance plug caps, you can and the system still work fine, and probably deliver you a stronger spark. BUT, there is the chance that you shorten the lifespan of the ignition coils as they were designed around having that 10K resistance in the plug caps. That's completely a theory, so take it with a very small grain of salt.

Regardless of what route you decide to take, I think it is a very good idea to take apart all four of your plug caps and clean up the internals with some sandpaper. I just removed all four of mine and some of them had a decent amount of corrosion on the internal parts. I sanded them down with some 400 grit sandpaper, reinstalled the parts the way they came out, and I wound up with a much stronger spark all the way around. The bike seems to be responding much better now and will even idle for me at a steady 1000RPM. I even did a plug chop last night and my results were rich on all four! You don't know how pleased that made me since I have all of my mixture screws anywhere from 4 to 5 turns out. Finally, I'm getting the results I want!

 

Thanks bro...much appreciate the explanation on dis-assembly of those caps. I tried before for 15 or 20 minutes to get that damn orange boot off but finally gave up. I am going do as you suggest this afternoon and also borrow my neighbors multimeter to check resistance across the board.

One question I had was did any of that cleaning up of the caps help solve your arcing problem or did it just lessen the severity? This is whats been driving me nuts. Hopefully, today's actions will get me closer...

 

Actually, yes! I was getting a significant amount of arcing on the number 2 cylinder, which I had a 18K Ohm measurement on. After cleaning up that cap, it Ohm'ed out to 11K and the arcing went away. I guess the path of least resistance is now through the plug cap, rather than on the valve cover!

 

SWEET! I am pretty excited to get those caps apart and hopefully put this this issue to bed! I'll let you know how it turns out. Thanks again

 

Hope it works out for you. My plug caps had no visible signs of cracking, even under the cheap-o magnifying glass I had, but I would suspect that no matter how clean your internals are, if you have signs of cracking, it will still arc.

Also, I know I said I was going to remove the dielectric grease I put on the plug cap internals, but I left it on and even applied it to the other two plug caps I had not yet dug into. So far, no ill effects other than the initial rise in resistance, which turned out to be my multimeter battery running low and giving weird results.

 

The only thing I found on my caps is if you take off the orange rubber from the bottom there was moisture in there. I put a thin coat of Di-Grease in there and they stopped arcing.

 

Broke down and bought a compression testing set with a smaller spark plug thread. Tested my warm engine, throttle fully open, and a battery charger on the battery.

1 - 170 psi
2 - 175 psi
3 - 170 psi
4 - 175 psi

Cool. This bike is ready to rock

 

That's like brand new!

 

it seems that the PETCOCK preforms no
function WHATSOEVER except to direct fuel from one direction to another,

A HIGH QUALITY BRASS MULTI PORT (NATURAL GAS) MULIT PORT SELECTOR BLOCK CAN DO THIS JOB JUST AS WELL, AND CAN BE HAD AT HOME DEPOT OR GRANGER OR A PLUMBING SUPPLY FOR LESS THAN $10.

YOU WOULD HAVE ONE LINE FEEDING THE IN PORT (GAS FROM TANK) AND YOU HAVE A SWITCH KNOB THAT IS A MANUAL SELECTOR FOR WHICH OUTGOING PORT YOU WANT IT TO FEED... SINCE
YOU USE THE HI QUALITY GAS MODEL , IT IS PRECISION MACHINED, AND DOES NOT LEAK ( ITS BUILT TO PREVENT PRESSURIZED GAS FROM LEAKING) SO LIQUID FUEL IS NOT EVEN A CHALLENGE TO IT..
ITS ABOUT THE SAME SIZE AS A XJ PETCOCK...

JUST A THOUGHT... PUT A "Y" SELECTOR BLOCK IN THE INCOMING FUEL LINE JUST BEFORE THE GAS BLOCK AND THEN YOU CAN SWITCH FROM STD TO RESERVE TANKS...

DONT THINK THEY WOULD EVER WEAR OUT.....

JUST ..THINKING OUTSIDE THE BOX....LOL

 

AS FOR THE PLUG JACKETS ARC'ing... WHEN THEY GET OLD, THEY SHRINK, ( AS IN WALL THICKNESS) AND PERHAPS YOURS LOOK GOOD BUT ARE TOO THIN TO PROVIDE HI VOLTAGE PROTECTION..

 

How would you connect this high quality natural gas "petcock" to the gas tank so that it would not leak?

The plug caps on the Maxim X's won't shrink since they are made of plastic.

Please, please, please, please turn the CAPS lock off. I feel like you're yelling at me.

 

Right!