Top end rebuild (Stuttering, Elec. Issues Prior) (Pic heavy)

I'm trying to track down an issue that started once I got home from the ride to Pennsylvania. Under hard acceleration, the engine bogs/stutters a little bit. It's especially noticeable around 4th gear, 45mph, 5k RPM -- I give it a good bit of gas, and it hesitates, and after two or so seconds it starts to pull.

Normally this would be a simple fix, but I've tried all the obvious things I could think of and nothing affects it.

In the past two weeks I:

- Got a new air filter

- Changed the oil

- Changed the plugs

- Put the valves in spec

- Cleaned the carbs

- Set the floats

- Adjusted the carbs with a Colortune

- Synced the carbs

- Rebuilt the clutch

- Checked all vaccuum hoses/boots

- Checked the resistances on the ignition coils

But no luck, still hesitates under hard acceleration. Sometimes it even feels like it's going to cut out. What haven't I checked?

It can't be anything like wrong jet size or something like that, because it always ran GREAT. After the 1,300 mile trip, something changed or broke or moved or wore out.

The only thing I have yet to check is the electrical system behind the ignition coils.

 

Re: I need your brains

Check the slide diaphrams for leaks. Take them out and hold up to a light. You should not see any light comming through, pay close attention to the outside and inside edges. Pull the diaphram a little and look for cracks. Check the slides and make sure they moove frely and pass the clunk test. Check your plugs, they are probably a little black from soot.

 

Re: I need your brains

You forgot the FUEL PUMP. Your bike has a fuel pump. Maybe you have a loose wire; or a piece of crud got into it.

Sure sounds like fuel delivery, unless you have one or more spark plug caps that are loose (or their CORES are coming loose.) Look inside the plug cap, there are two screwdriver slots on either side of where the top of the plug goes; ensure the resistor core isn't loosening up. You might also want to unscrew the caps from the wires, "lop off" about 3/8" and screw the caps back on.

But I vote fuel delivery.

 

Re: I need your brains

mlew, I did thoroughly check the diaphragms. No cracks/tears or anything of the sort. Also polished the bores real well so they clunk very satisfyingly.

Fitz, I checked the coils and wires last week, even lopped a little bit of the end and screwed them back in like you suggested. Everything about the coils checked out. Could it be anything electric before the coils?

I have not tried testing the fuel pump -- next thing I'll do tonight. It was odd to me because when I checked the float levels last week they were really low (well, not really low, but just out of spec) and I thought "well daggum that has to be it"...but now that they are set correctly there is no change. You could be right that the problem is getting fuel to the carbs. I am running a fuel filter -- no gunk in there -- and the petcoque is new.

 

Re: I need your brains

Is your exhaust and intake stock or have they been modified in any way? I'm curious to know what color the plugs are.
Fuel delivery is a good possibility, make sure your bowls are staying full first. The location of that filter is also critical, don't mount it to high or the pump will have a hard time pushing fuel to the carbs.

 

Re: I need your brains

Everything is stock.

I just checked the plugs. They come out very light brown -- almost too light. At least that should tell us that it's a lack of fuel rather than too much.

The fuel filter is half way in between the pump and the carbs (that hose is probably about 6-7 inches long). The vacuum line from the intake to the fuel pump could be in suspect. Need to check that too.

It runs really well, better than it ever has, except for that first little but o' throttle.

 

Re: I need your brains

The wire lopping and screwing back on was in reference to the spark plug caps. Also be sure the resistor cores inside the plug CAPS aren't working loose.

But I agree it sounds like fuel delivery.

 

Re: I need your brains

Update on this:

I re-tubed the whole fuel system, from the petcoque to the carbs, put on a clear fuel filter, cleaned/tested/rebuilt the fuel pump, replaced the vacuum hose from the #2 intake to the fuel pump....same result.

A plug chop would tell me everything I needed to know -- so I chopped the plugs and they were white. Looks like my gasoline is playing hide and seek.

!!

Floats are correct, even a little on the high side. Like mlew said, it could be the diaphragms, which I already throughly inspected. Time to inspect them again.

 

Re: I need your brains

Plugged gas cap vent?

 

Re: I need your brains

Update on this debacle:

I "rebuilt" the gas cap. It was in good condition, nothing out of the ordinary like dirt or old gas clogging it up. Same bike performance.

Then I re-cleaned the carbs, doubled checked the diaphragms, but everything is good as new. Bike still hesitates.

So then I realized the last major thing I did was service the valves, so I checked the valve clearances again. They are still in spec.

Finally, last night I realized I hadn't run a compression test in a while. All plugs were pulled, and I hooked up the gauge to #1. Wide open throttle aannnndddd....the starter turns over a couple times and the battery starts to die. Which is odd, because I have been riding every day trying to diagnose and the battery should have been fully charged.

I let the battery charge overnight, and this morning I run the test.

#1 165
#2 156
#3 155
#4 162

The manual recommends 145-167. WHEW Ok, no leaky cylinders, but now I'm starting to think I have a problem with my battery or charging system. ON TOP OF hesitation in acceleration.

This is the point I start to feel like a dope, after all the advice I've given other people but I can't figure out my own simple problem! :roll:

 

Re: I need your brains

Unscrew the plug caps and "OHM" them out, just the caps.

Replace the plugs with brand new ones.

However: Your "battery and/or charging system problem" could be related...

(Nice compression numbers, BTW.)

 

Re: I need your brains

The caps check out. Checked them all when I snipped a bit of the coil wire a couple days ago. They're only a year and a half old (I replaced them all when I got the bike). I just got done disassembling them all and inspecting the insides.

New plugs, check.

And you're right -- the battery is on the charger now, and if I go take a ride when I know the battery is fully charged and there's no stutter for a short distance, it could very well be electrical.

Gonna break out the multimeter and see what voltages the battery is giving me.

I'm surprised about the compression numbers. This bike was one of those "needs to be rescued from the hands of the abusers" cases.

 

Re: I need your brains

I really don't see ignition problems causing white plugs on a plug chop. Since the symptoms match fuel starvation, I think you were on the right track originally.

Kind of a hard thing to check off of a dyno, though. Is the fuel filter clear (as in see-through)? If so, can you compare the fuel level versus any air bubble in the filter when the bike is running well to when it's started bogging under load?

Is the filter new? Old? Did you try a new one?

Does you setup allow you to run on Prime? If so, try that to see if it changes or removes the bogging issue.

 

Re: I need your brains

Yea, no matter what I've been working on, it's ringing in the back of my head "The plugs were white...no fuel."

The fuel filter is brand new, and clear. I positioned it so I can see it while I ride. It stays full no matter the riding conditions.

I checked the petcoque, too. Same problem even when set to prime.

It is good I checked the electrical system, though. I do indeed have problems in that department. The battery is reading 12.8v @ 5k RPM, which is well below the recommended 14.3v - 15.3v. Looks like the lean problem is going to have to go on hold while I slap in some new alternator brushes.

The more I ride it, I realize the stuttering before acceleration only happens sometimes, and even then only below 5k RPM. Sometimes I'll be a cruiserist at 4.5k RPM and punch it, and it will stutter for two seconds and then accelerate, sometimes I'll punch it and it-will-fly.

And I'm pretty confident it's not the carbs -- you can only clean and rebuild those so many times before you go to bed at night and have dreams about them, which is the point where I'm at with 'em.

(thinking out loud) It's something that's keeping gas from all four cylinders. If a float was set wrong, they'd all have to be set wrong. If a boot was leaking air, they'd all have to be leaking air.

 

Re: I need your brains

Try getting it warmed up and see if you can reproduce the problem.....once you can reproduce it consistently, then turn the choke on a little bit and crank the throttle again.......this adds fuel from a separate circuit from the normal pilot and fuel circuits..........if, with the choke on slightly, then you've confirmed it's a fuel delivery problem, and that narrows your search a bit.

 

Re: I need your brains

Just got back from watching the NHL game @ Taco Mac -- darn those Red Wings.

However, the stuttering got progressively worse as the engine warmed up. Once it got to optimum running temp (about 10 mins of riding, smooth 1200 RPM idle w/ zilch choke), any acceleration I did made the engine sputter and almost cut out -- you'd think it was running rich! Basically had to take the roads where I could coast home.

Chacal, while it was sputtering @ 1/4 throttle, I gave it a little choke (then a little more and a little more) and there was no change. No positive change, at least. It started to bog AND sputter. Bog like it's running rich. Sputter like it's....lean?

When your bike is warmed up properly and you give it choke -- you know what I mean -- it bogs because you dumped a bunch of gas in there. That's what the bike did as I was riding and pulled the choke... except it still sputtered and hesitated as well. This is where my brain explodes.

I need to stop riding it. Probably doing more harm than I realize.

 

Re: I need your brains

I don't suppose it could be something as simple as a bad tank of gas

 

Re: I need your brains

I wish! I suspected that at a point, and now I have like 11 quart-sized oil containers in my garage filled with gas, haha.

 

Re: I need your brains

You mentioned you re-tubed the fuel lines. I had a problem much like yours and it ended up being the new fuel lines I'd installed. What was available was a blue plastic aftermarket variety sold by a local bike repair shop.

What was happening was the bike after some running became hot around the rear of the carbs, that was all the fuel line needed to bend over on itself & it started choking the supply. Repositioning the line would get it running again but it was a temporary fix & invariably it would shift and bend badly, I had to replace it with line that was more rigid & less prone to a case of the bendys.

Just relating my prior joy...

 

Re: I need your brains

Try running her with out the fuel filter. I hand a lack of fuel problem on my 750 and it turned out that the filter was causing fuel starvation.

 

Re: I need your brains

KA1J, I eliminated any chance of tube-kinkage when I put in the new lines. The original fuel tubing was arranged in a way that certain points of the tube could have bent over on itself, but the tube was so old it was pretty much "baked" into a certain shape. Or maybe that's the way it comes from the factory? Regardless, I put in the new lines with kink-proof tube in a kink-proof fashion. Refer to my unnecessary drawing below.

Ground-Hugger, I did try that at a point, but to no avail.



I need to fix the charging system before I take it out on the road anymore -- just to eliminate that possibility. Also going to check the color of the plugs one more time to see what last night's ride did to them.

 

Re: I need your brains

Have you considered your TCI module? The ignition timing is controlled by it and you could have an intermittent going on with a bad solder joint or a dried out electrolytic capacitor. From your diagnosis, it sounds like the problem occurs under acceleration and therefore could be timing related? Sounds like you've gone over the fuel delivery so maybe the problem is electrical, just a guess...

 

Re: I need your brains

and of course there is no way your fuel filter is connected backwards

 

Re: I need your brains

STUMPED

Plug chopped again, and I've never seen a plug like this before. On one plug, half of the tip was white-ish, half was sooty. :?

Last things I've done:

- My stator coil was OHMing out of spec, new (used) one came in today

- Replaced the battery

- Reset the cam chain tensioner

The CDI module is the next thing I'm going to try. Even used they are pretty pricey. But there's no way to test the darn thing other than trying another one.

Correct, they were kind enough to put a "flow arrow" on it

 

Re: I need your brains

white tipped carbon dusted plug. Doesn't that fit in with your theory of the engine starving out at high speed? Just for the hell of it - remove your fuel filter and try to have your fuel line's curves as subtle as possible. It doesn't cost anything, it's an easy job and it will at least eliminate another possibility. I installed a fuel filter early in the spring because I only had the one in the tank. First ride - engine starved out. The line must have kinked just enough to restrict the flow. I removed the filter - no more problem.

 

Re: I need your brains

I'm following your post because I think I have your exact same problem on my 86 maxim x 700. A lot of the people I spoke with said they had a similar issue that was fixed after they replaced the stator. How is your issue now after replacing it? Have you replaced the regulator/rectifier as well?

 

Re: I need your brains

The gas ate through the plastic on my fuel filter, so it looks like I'll be trying your suggestion while a metal one comes. I wish that could have been the problem, but the bike started acting up before I changed anything in the fuel lines.

I put in a new stator and I'm waiting for a new regulator/rectifier to come, and then we'll see what happens. My manual doesn't give any test reccomendations for the regulator, it just says "try everything else first and if your voltage at the battery is too high or low, replace the regulator/rectifier."

Good to see another GA local, too.

 

Re: I need your brains

Wow! The gas ate the fuel filter??? NOT normal, that could be part of the problem. Did you get an automotive/motorcycle filter? REALLY odd that is.
Voltage regulators are not hard to test, just look at the voltage from idle through 3000 rpm. If the voltage doesn't rise from static above 2500 rpm (or thereabouts) you either have bad brushes or the regulator isn't happy. Check all connections and ohm out the lines. If all else fails, I would agree the regulator is at fault.

 

Re: I need your brains

Yea I've never seen that before on a fuel filter. I thought maybe it had melted somehow when I first looked at it, but I hadn't run the bike for two days and the plastic was cold but goopy.

I think I posted the numbers before, but when I have the multimeter on the battery, it's at 12.5v at idle and only rises to 12.7-8v at 5k rpm, whereas the manual specifies somewhere around 14.5v when things are as they should be.

The stator lines OHMed just slightly out of spec, but even that can be kind of misleading because a stator with in spec wires could have bad brushes (like you said). I found a good used stator from an earlier model XJ, and it OHMed in spec, plus the brushes looked alot better.

Just waiting on the regulator to come and we'll see what happens.

 

Re: I need your brains

Have you checked the vent on the gas tank? Could be stopped up preventing fuel from entering the carbs

 

Re: I need your brains

Yea, BigFitz mentioned that before. I took the entire thing apart and no one told me it had a zillion little parts to hold the key flap closed, lol. Luckily I tracked down all the parts that flew off.

 

Re: I need your brains

- Removed fuel filter

- New fuel pump

- New stator

No change in performance. Regulator/rectifier still inbound.

 

Re: I need your brains

Is your bike losing power when it sputters? Gauges and headlight flash and almost go out. Mine was and after opening up the cluster I saw that my ignition switch was damaged by PO and it was very loose and hardly making a connection. I repaired tonight so hopefully it will be fixed tmo when I go for a test run.

 

Re: I need your brains

hahaha i thought i was the only one... turned out to be that i was setting the float heights using a gas-resistant ruler which had 1/16" marks on one side and 1/32" marks on the other--which i mistakenly mistook as mms. big duh moment.

coils can be intermittent under certain conditions; they'll ohm out ok, but when they get hot, or vibrate at the right frequency, they'll open circut... which seems consistent with this only occurring below 5k rpm. but then again, you had 4 white plugs when you chopped. so hmmmmmmmm....

i cant remember if you said you changed your plugs or not. whenever i have a bizarre running issue that completely stumps me, 6 times out of 7, changing the (seemingly fine) plugs will do the trick. definitely try replacing them if you havent (cant hurt).

does this only happen when you snap the throttle open fast? and/or does it happen when easing it (more) open? does it do it in neutral? or only under load? is it worsening? your battery sounds sad. i would have tried a different/new one before the stator coil. like sh!t gets all in the bottom and starts to short it out. its a long-shot but, maybe, when you accelerate, the crap in the bottom moves towards the rear and shorts out a few cells. but it doesnt do it at high revs. so hmmmm. you got a real stumper there... sorry man i know how you feel. all like: 'i know my sh!t, ive fixed every issue that this bike has thrown at me, big or small... this should be easy I SHOULD KNOW WHATS WRONG!' and then you sit there and you feel like the solution is about to pop into your head, but it doesnt. so then youre all 'well if i just go through the carbs one last time then maybe ill see something ive overlooked'. and they're all spotless and perfect and just like new, just like how they were when you just put them on last. (well perfect except for that one jet that the PO kinda gnarled-up)
well maybe i cant speak for you but thats how i would be feeling. at least its not that feeling where you know which part needs to be replaced, but its the most expensive one on the entire bike. or is located deep in the bowls of the engine and requires much disassembly and new gaskets and labeled tupperwares.

i would save the CDI till last. im thinking no on that being the cause. or maybe theres a loose connection/broken wire somewhere around there that vibrates just right, or moves when you accelerate just right... as someone said, check the ignition switch. mine cuts in and out sometimes too. is there a magic rpm where the whole bike acts up? maybe, given your speed limits and gear changing habits, you happen to only cross that rpm while accelerating? also check your battery posts (or whatever they're called). i had too long of bolts in there once, so i thought i was getting it tight, but the bolt was running into the battery a little and was constantly vibrating loose and would cause crazy intermittent power loss. (more random tho).

anyways... good luck with your heavy burtation, im interested to know how you finally resolve this.

 

Re: I need your brains

hahaha i thought i was the only one... turned out to be that i was setting the float heights using a gas-resistant ruler which had 1/16" marks on one side and 1/32" marks on the other--which i mistakenly mistook as mms. big duh moment.

Yep, I checked em again and again...I could do it blindfolded with one hand!

coils can be intermittent under certain conditions; they'll ohm out ok, but when they get hot, or vibrate at the right frequency, they'll open circut... which seems consistent with this only occurring below 5k rpm. but then again, you had 4 white plugs when you chopped. so hmmmmmmmm....

Someone was parting out a Seca II the other day and I got him to send me both coils. I'll try them once the get here. That does make sense, because the problem does get worse as the bike warms up. If I was running lean, I'd figure that would be the opposite -- as the bike warms up it'd need less fuel...and the plugs were white that one time. After trying it again later there were spots of soot.

i cant remember if you said you changed your plugs or not. whenever i have a bizarre running issue that completely stumps me, 6 times out of 7, changing the (seemingly fine) plugs will do the trick. definitely try replacing them if you havent (cant hurt).

Yep, I've definitely made NGK rich through this process lol

does this only happen when you snap the throttle open fast? and/or does it happen when easing it (more) open? does it do it in neutral? or only under load? is it worsening? your battery sounds sad. i would have tried a different/new one before the stator coil. like sh!t gets all in the bottom and starts to short it out. its a long-shot but, maybe, when you accelerate, the crap in the bottom moves towards the rear and shorts out a few cells. but it doesnt do it at high revs.

During the first 10-15 minutes of riding, it will only hesitate when you snap the throttle fast. After that, any acceleration and it will stutter -- and I wish I could get people to ride it to see what I mean -- but it's a sharp stutter. Not just a feeling like I'm losing power, but it's like all the sudden the cylinders are fighting against each other. Then I'll give it MORE gas and it will stutter less and start to accelerate.

I did try a difference battery before I put the new stator in there. Same result, as far as what the multimeter told me.

so hmmmm. you got a real stumper there... sorry man i know how you feel. all like: 'i know my sh!t, ive fixed every issue that this bike has thrown at me, big or small... this should be easy I SHOULD KNOW WHATS WRONG!' and then you sit there and you feel like the solution is about to pop into your head, but it doesnt. so then youre all 'well if i just go through the carbs one last time then maybe ill see something ive overlooked'. and they're all spotless and perfect and just like new, just like how they were when you just put them on last. (well perfect except for that one jet that the PO kinda gnarled-up)
well maybe i cant speak for you but thats how i would be feeling. at least its not that feeling where you know which part needs to be replaced, but its the most expensive one on the entire bike. or is located deep in the bowls of the engine and requires much disassembly and new gaskets and labeled tupperwares.


Can't tell ya how many times this week I said I was giving up! But the problem is there, and something is causing it, and I will find it. When or how, I don't know lol.

i would save the CDI till last. im thinking no on that being the cause. or maybe theres a loose connection/broken wire somewhere around there that vibrates just right, or moves when you accelerate just right... as someone said, check the ignition switch. mine cuts in and out sometimes too. is there a magic rpm where the whole bike acts up? maybe, given your speed limits and gear changing habits, you happen to only cross that rpm while accelerating? also check your battery posts (or whatever they're called). i had too long of bolts in there once, so i thought i was getting it tight, but the bolt was running into the battery a little and was constantly vibrating loose and would cause crazy intermittent power loss. (more random tho).

Good ideas, I will check the electricals on the handlebars. It does the acceleration stutter between 4k-5.5k RPM, and that's where the bike has the most vibration anyways. It's very consistent, if there was a loose connector/wire somewhere, you are right that it would be more random. Plus the way it gets worse when the bike warms up tell me it's something else, too. But I will check those things because I never have before.

anyways... good luck with your heavy burtation, im interested to know how you finally resolve this.

My bike is running as smooth as her news report!

 

Re: I need your brains

Are you sure they were spots of soot? I hope so. Running too lean under load starts burning the aluminum of the cylinder head. The effect on the plugs is little specs of burned aluminum.

 

Re: I need your brains

oh man oh man oh man. emulsion tubes! check to see if they're ovaling out: (the thing the needle slides into, with all the holes in the sides and jet at the bottom). the orafice that the needle slides into should be round, not oval. check out this link. secondish picture from the top. but then again.... white plugs.... im sure too that the holes in the bottom of the bowls are all free and clear?

o wait i think i may have just found out what it is... from this thread

haha, "umpteenth"
i found that thread searching for emulsion tubes haha.
so do i win the prize? (lol what was it i said about coils, again...)

 

Re: I need your brains

Yeeaa I thought the same thing, but it wipes off with a finger swipe and it very fine like soot.

Oooo, some helpful threads, thanks for pulling them up. I'll check the emulsion tubes and see how they are. I mean, I always clean them and polish them and hold them and caress them, but I'll check for ovalation this time.

Same with the pickup coil, it's just one of those things I would have never checked. It shall be inspected as well.

The coils come tomorrow -- should have some results of SOME KIND by the end of the day. Oh boy!

 

Re: I need your brains

Nothing new, just a quick video status update:

[flash=425,355]http://www.youtube.com/v/uK7c8Djm8eQ.swf[/flash]

 

Re: I need your brains

Put in the new coils, new plugs -- same result. Stutters sharply under acceleration and worsens as the bike warms. Although with the new coils, it eliminated a vibration around 4k RPM, and it revs alot smoother. Odd.

Nothing I've done since the beginning of May has had any effect on the stuttering problem, though. Not even the slightest bit. Exact same. What demon lurks inside there!?

Recap of what I've done since May 4th:

- New air filter

- Changed the oil

- Changed the plugs (5.25.2011)

- Put the valves in spec

- Cleaned the carbs x92

- Set the floats

- Adjusted the carbs with a Colortune

- Synced the carbs

- Rebuilt the clutch

- Checked all vaccuum hoses/boots

- Replaced stator

- Replaced rectifier/regulator

- Replaced both coils

- Tested pickup coil

- New exhaust gaskets

- New fuel pump/lines

- New battery

 

Re: I need your brains

im 87% sure its the pickup coil(s). they'll seem ok on the bench, but at their resonant frequency, they'll act up. sorry man i hate throwing parts into stuff too, without solving the problem.
on the bright side, it'll run better than it did when it was brand new when you get it going right!

 

Re: I need your brains

Yep, gonna try the pickup coil next!

And that's the mentality I'm trying to keep: Once I nail this little issue, this bike should have no more issues for a goood long while lol.

 

Re: I need your brains

Check the grounds!

It's always the grounds!

I always go from the battery terminal to the starter and then ground EVERYTHING ELSE there too.
The cylinder head,
The voltage regulator,
Anything that has a sensor.

Anytime you have something weird blame the grounds first!

THEN check for bad connections.

+1 on the pickup coils mine were bad and I would have bet it was the carbs!

 

Re: I need your brains

Thanks for the suggestion. I have a pickup coil complete with rotor en route, and I'll check the grounds and connections in the meantime.

 

Re: I need your brains

Alright, a little update on this monstrosity.

I put the new pickup coil in, but now have to wait for a clutch cover gasket because it required the penny-in-the-primary-gear technique to get the pickup coil rotor bolt off...point being, can't test the pickup coil 'till Rebecca Blackday when the gasket procures itself on my doorstep.

My battery has been dying overnight. I charge it during the day, in the morning it's almost completely dead. This is while connected to a non-running bike. Yikes.

So yesterday, I took the fully charged battery with me to work. Checked it every hour, and it showed 12.8v all day. Ok, the battery is good. With the multimeter connected, I screw in the connectors on the bike into the battery, the multimeter immediately shows 11.3v. Just drops. There is something pulling electricity out of the battery even with the bike off. Then I start the bike, and even @ 5K RPM, the battery goes 11.3....(two seconds)...11.2....(two seconds)...11.1. You get the picture. Battery isn't charging! This is with a new stator and rectifier.

I removed the entire wiring harness -- the whole shabang. Checked and cleaned all the connectors, fuses, looked for heat trauma on the plastic and for any melted wires. Everything looked to be in good shape. Checked all the grounds, too. But I can't really test anything until the clutch cover gasket comes in.

 

Re: I need your brains (Stuttering, Elec. Issues)

next time, just put it in 5th and hold the brake ; )
last night i found a short by just unplugging one connector at a time. you could try that...
or start w/ harness off (if it still is) and start plugging things in one at a time.
not charging, ugh, man... try old rectifier/regulator/coil?
did you start it w/o clutch cover? o_0
just a thought but my short was caused by (prob similar on the 600) uh... so you know that plastic thing that holds the rotor brushes? well one of the screws that holds that little assembly to the alternator cover rubbed through the shrink tubing on one of the brush's wire connectors. i wasnt getting any charge either...

did/does/will your battery drain when key is on LOCK?

dude your bike needs to stop being a rebellious teenager already and start acting its age. maybe its time for a good heart-to-heart.

 

Re: I need your brains (Stuttering, Elec. Issues)

I tried to talk sense, but it's in that "I'm mad at my dad for no reason, going to smoke and get a tattoo" phase for sure

Was just about to update when you posted. Here is where it stands:

- Removing the wiring harness and cleaning it and checking it so very gently fixed the charging issue. There must have been a short/bad connection somewhere. WHEW.

- Test run with the new pickup coil. No change.

HOWEVER -_-

- #1 cylinder is getting no gas. I pull all the plugs and #2, #3, #4 are black, #1 is white. I think the #1 manifold or the vacuum tube is leaking air. Investigating. This could very well be the stuttering issue, however I'm not sure why I couldn't see these symptoms before.

At least a cylinder getting no gas is a visible issue I can sink my teeth into.

 

Re: I need your brains (Stuttering, Elec. Issues)

OK

The stuttering turned out to be an air leak on cylinder #1 -- the vacuum hose from intake to petcoque was the suspect. Why I didn't catch this before, I don't know.

Now, no matter where I set the idle screws, all four plugs foul and are soot covered.

Unless, I take the airbox off. I even tried running with just the air filter out. Runs crummy. But only when I take the entire airbox off, the bike runs fine. Great actually.

So this tells me my fuel mixtures are wrong. Too much gas, not enough air. But no matter how I set the gas (floats, mixtures screws), it will not even ride 5 feet unless the airbox is removed.

About four times today I was ready to push this off a cliff and let it sleep with the fishes. I can't tell you how many times in the past two days I've taken the entire bike apart and put it back together.

I see the symptoms, but for some reason the fix eludes me.

 

Re: I need your brains (Stuttering, Elec. Issues)

Unless your air filter is plugged almost solid, it's doubtful that the air system is the problem.

Your fuel jets are too large (or reversed?), your air jets are too small (or reversed), the fuel levels are WAYY-Y-Y too high, the choke plungers are stuck "open" somehow, or the engine is so horribly out of synch that, sometime in the past, the engine has been "tuned" to only run at an incredibly rich condition, or someone has installed some kind of "hot rod" fuel system kit and messed up a whole number of things all at once.

But I would start, if possible (buy some new plugs), with trying to re-synch the engine. You'd be surprised how many issues that might resolve. If that doesn't solve the problem, then verify the choke system (and not just via the lever; make SURE the choke plungers are actually fully closed by hand and eye), and then pull the carbs and start looking at the jets and the tip of the choke plunger(s).

 

Re: I need your brains (Stuttering, Elec. Issues)

Alright Chacal, I think you were on to something with the choke not closing correctly. There was little to no change in idling between half choke and no choke...that should tell me something right there.

It just so happens that I had a spare rack of carbs I bought a long time ago to use parts off of. I cleaned it up, moved all the parts from the old carb rack to the new one (bench sync, floats, yadda yadda), and sure enough it fired up like normal. The choke was operating like normal, too. Well that's that.

However, now I'm back to square one on the original issue. The bike rides for ten or so minutes, and the stuttering is back. I think it's safe to rule out the carbs as the cause, because I vacuum synced after that run and the stutter was still there -- with a different rack of carbs.

The bike ran great for the past year with stock parts/adjustments/sizes, so I know it isn't an issue where the bike has been modified and I'm incorrectly compensating. Everything is as it should be.

I have a feeling this issue is somewhere in the engine, because nothing I have done on the outside of the engine has had any effect on the stuttering. I've replaced everything on the bike with good used parts (including the carbs now). Well, except for the CDI box, but I doubt that has anything do do with it.

Plus, any time I've test ridden it in the past two weeks, there's a vibration and knocking noise that gets worse and worse every time. I think it might be time to pull the engine and do an overhaul, unfortunately.