XT600e 2002 heavy misfire/bogging
 

Hey folks,

I'm new to the forum, but not new to the xt and the never ending problem sourcing with it.
So to make it short and straight to the point....I've got a problem with the bike and it's been persisting for the past couple of months.

The problem:
The bike either misfires or doesn't get the right amount of fuel going to it, at around 2000-3500 rpm. It idles great and doesn't have any problems running good on choke, but as soon as you shut the plunger back and attempt to give it throttle, it bogs, misfires and throws tantrums. It starts no problem at all, just press the button and on it goes, it may need persuasion on colder days with the choke.

The remedies:
What I have tried so far is to:
1. Change the ignition barrel ( there was an attempted theft on my bike so they cracked the barrel )
2. Change the battery
3. Change the Reg/Rec (reg/rec failed to charge my battery because the pins got corroded due to the salting of the roads ( UK ))
4. Change the relay ( for the heck of it, it was cheap )
5. Swap out with a 550s carbs ( a friend let me try his 550 carbs on and the bike started up and ran no problem, but it would still do that misfire/bogging thing )
6. Ultrasonically clean my carbs ( properly cleaned them out and blew out everything with compressed air )
7. Re-build the entire carb with new jets and o-rings ( apart from changing the diaphragm on the second carb (there are no holes/tears/stretch marks, just no sign of wear on it) )
8. I've ordered a second hand XTZ660 (tenere) carb 4000 miles on it, will need cleaning, but should be a straight swap ( I'll try it and see if it does that still )
9. I plan on checking the stator and pick-up coils, maybe tomorrow if I can get some guidance on it.. :] need help here with what to look for
10. The last thing I can possibly think of that would cause this is the CDI unit...unfortunately I do not have another one to try and they are quite expensive, I need options here...anyone? EDIT (I was wrong here the correct terminology for this make, model and year is a TCI unit)
11. Forgot to mention, I also checked the valve clearances to make sure that its not from air blowing back into the carb from the valves
12. Also the obvious air filter is not the issue here either, it would not cause the bike to act in the manner as it does, at that specific rev range, I've also ran the bike without it and it's the same issue.
13. Changed the intake manifolds as well (so they are brand new and I sprayed starting fluid around to look for air leaks...no leaks)
14. New ignition coil
15. New spark plug cap
16. New spark plug

Further:
I have documented the symptoms of "the problem", please find the video [{HERE (CLICK ME)}].

EDIT:
Sorry forgot to mention, yes I changed the ignition coil and I've tried 3 spark plugs, 2 old 1 new.
Everything inside the carb has been cleaned and replaced with new parts. float height is set to manual specs at 26mm.
The sync is set per manual as well, 5mm on the first carb just as the butterfly valve is rising on the second. mixture screw was adjusted for 3.5 turns out and then altered once the bike warmed up to 4 - 4.5 turns out.
Both slides operate freely and smoothly.
Also the gas tank is completely free of rust and is clean on the inside.
All the hoses that connect the carb parts to each other are clean and in good condition, same with the fuel line to the carb.
No kinks in the hoses either, the flow of fuel is unrestricted.

EDIT 2
The details of how the bike operates:

Engine cold
When the engine is cold, it's a bit difficult to start, but with the choke on it will fire up. It may die for a second, but it will start again no problem.
When the engine is cold, giving a bit of throttle will make it sputter and misfire bad, and it will not be able to go over the 2-3.5k rpm or even die. Unless you put the choke on, then it goes to 3-3.5, and you can drive it on choke, but obviously its just counter-intuitive to make the engine do that.

Engine hot
When the engine is hot, it's easy to start, both with and without the choke. It will rev higher when the choke is on and the engine is warm at 3.5-4k rpm.
When off the choke if you blip the throttle it will go over the 2-3.5k rpm and can stay higher, but if you go slow on the throttle it will die ones it reaches that rpm range.

The specifics of the pick-up coil.
Results:
Engine cold - 225
Engine cold, Ignition switch on - 250
Engine cold, idle - 270-300
Engine hot - 255
Engine hot, Ignition switch on - 282
Engine hot, idle - 310-340
Engine hot, throttle - 350-600

The jet sizes that came part of a kit
Jet kit..............................Original
Main 130..........................130
Secondary 110..................104
Pilot 50..............................48

Hi and welcome! Did you remove and clean filter inside carb? Float height correct? New spark plug? Change the ignition coil and spark plug cap? And adjust the sync on the carb?

So can you ride it around at low revs/ speeds ok? Like on 30mph roads? If so i had a similar issue and have just found that removing the snorkel and a DNA air filter fixed the issue for me so was running too rich and not breathing right.

Thanks rock !

Sorry forgot to mention, yes I changed the ignition coil and I've tried 3 spark plugs, 2 old 1 new.
Everything inside the carb has been cleaned and replaced with new parts. float height is set to manual specs at 26mm.
The sync is set per manual as well, 5mm on the first carb just as the butterfly valve is rising on the second. mixture screw was adjusted for 3.5 turns out and then altered once the bike warmed up to 4 - 4.5 turns out.
Both slides operate freely and smoothly.
Also the gas tank is completely free of rust and is clean on the inside.
All the hoses that connect the carb parts to each other are clean and in good condition, same with the fuel line to the carb.
I will try a new spark plug cap tomorrow, since its 23:00 :D...don't wanna be a dick to the neighbors ^^

It's the opposite I can ride at high revs, but misfires and throws tantrums when I attempt to cruise at 2000-3500 rpm, that is if I am lucky enough to get it off the line without the choke.
It's not that andy, definitely sure on that since, you can see the bike is running without the side covers for the airbox.

Its 2,5 turns out and was it not 7mm gap?

I tried the manual specs at 2.5... that didn't work for me, it may be because of the aftermarket exhaust it's basically a straight pipe. But yeah it seems to work better at around 4 turns out. You are right it is 7...might need to come back to that one

Well i have aftermarked exhaust and KN filter and still no problem 2,5 turns, it only works on low rpm. Maybe you need bigger main jet, what size you have?

The jets came as part of a repair kit

Primary 130
Secondary 110
Pilot 50

check spark plug for colour if its lean, would try the 140 and maybe do the 120, dynjoet kit is 115. My bike runs perfekt on this kit.

the spark plug is good, neither white nor completely covered in carbon, it's dry as well, it's burnt halfway through the tip so I think the jets are good
Plus it ran on the 550s carbs no problem, but it was still doing that misfire thing

A suggestion came in saying it could be the pick-up coil, anyway to check it:?

Pickup coil resistance: 184-276 Ohm at 20·C (68·F) (Blue/ Yellow - Green/ White)

Measure in normal temp and then heat it and check again.

I just went and measured the resistances on the pick-up coil.
Results:
Engine cold - 225
Engine cold, Ignition switch on - 250
Engine cold, idle - 270-300
Engine hot - 255
Engine hot, Ignition switch on - 282
Engine hot, idle - 310-340
Engine hot, throttle - 350-600

your thoughts :?

Its in range as you see, think back when did problem start, have you done any changes before this or did it just start over night? Open CDI unit and check all connections.

Think it could be the TCI?
the advance curve
https://scontent-lht6-1.xx.fbcdn.net...45&oe=5946F920

EDIT
I think you are right...my reg/rec died and it didn't charge the battery, so I got stuck in the middle of nowhere when that happened...hahahah how lucky...anyway fortunately for me I asked a guy to give me a push and I bump started it...at the time I didn't know what the problem was and why my battery was completely dead, now that I look back on it, what happened was that the reg/rec failed and after that bump start upwards of 20V were going into the TCI...if that is possible...I think this may have damaged it

But honest to god I cannot remember how the problem started

Its hard to tell whats doing it, try find a box to test for your bike or buy a spare. Its never wrong having double of all the parts for easy fix of problems that takes hours and days to fix else.

I had posted on ADV that it sounds like the pick up coil/pulse gen failing . It still sounds likely with the numbers posted the resistance was good cold but went way high and out of spec as it got warm, may not be an issue. However I see here it has been said that it can get above that stumble and run high rpms fine . That's odd. From the other site I understood it would only get to the certain rpm range and not go above. These TCI's are fairly solid reliable and I've not heard of one failing , but an overjuiced one could have issues. At this point I'd definitely try to find a known good one to swap , wouldn't take but a couple minutes if you know anyone with one of these bikes.


I got your video to play this morning , watching it is difficult to see. If the motor is warmed up does it run on full choke like that ? When you had the choke all the way out it seemed to run up the rpms fine , did it ? The way your video showed it seemed more fueling than anything but the miss had some strange sounds that's hard to pinpoint. Some finer description of what it's doing at what settings ,choke-no choke, hot/cold ect.. fast throttle twist or slow twist . More precise info will help .

The university technician I mentioned has a couple of 550s, I'm not sure if their CDI/TCI is a match for this one. It looks like the 550s motor is similar to the 600, and I couldn't see points on top of the cam shaft, so it could be a pickup coil set-up.

The details of how the bike operates:

Engine cold
When the engine is cold, it's a bit difficult to start, but with the choke on it will fire up. It may die for a second, but it will start again no problem.
When the engine is cold, giving a bit of throttle will make it sputter and misfire bad, and it will not be able to go over the 2-3.5k rpm or even die. Unless you put the choke on, then it goes to 3-3.5, and you can drive it on choke, but obviously its just counter-intuitive to make the engine do that.

Engine hot
When the engine is hot, it's easy to start, both with and without the choke. It will rev higher when the choke is on and the engine is warm at 3.5-4k rpm.
When off the choke if you blip the throttle it will go over the 2-3.5k rpm and can stay higher, but if you go slow on the throttle it will die ones it reaches that rpm range.


You can also see that the pickup coil is within spec when it cold and hot with and without the ignition switch on. But that being said when you give it throttle or the bike runs it goes out of spec...I'm not sure if this is how the procedure for measuring it goes or if I should even concern myself with how much resistance there is while the bike runs...I just don't know.
In any case once the new carb arrives, that should eliminate the carb issue...if I really have to and the only thing I am certain that is left is the tci box then I'll get a new one, otherwise I'll try and see if the technicians tci boxes will fit.


EDIT
On the tenere forums, user drumnagorrach:

Just got 225 on mine with the injun cold . The fact that it runs seems to suggest that the pickup is working ,all it has to do is tell the ignition unit when to fire and ,not sure about this ,but how fast the injun is spinning .
On my Ducati and my Guzzi there is a crank speed sensor as well as crank position , but then they are both "dodgy Italian " systems which strangely have never given me any grief ,although vastly inferior to Japanese electrics !!!

He has a similar issue, but not as bad as mine, so our pickup coils have a similar resistance... at least when the engine is cold.

Measure is done with ignition OFF.

Thanks for that, also I'll be adding information to the initial post as I progress, this should help in the future if anyone has a similar issue to find all the information condensed in one spot. Let me know if I should add anything else, or if I've missed a crucial bit of information.

Any difference when you open the gap to 7mm?

The 550 cdi won't work on your bike . The 550 similar to the mid to late '80's kick start 600's but once they switched to E-start the cdi changed to a TCI setup, The kick start models run ignition off the stator and can be ridden with a dead battery(or even without ) , yours however runs strictly off the battery and the stator simply charges the battery so voltage is important to how it runs. You'll need a TCI from a '96ish thru 2006 ??? 4PT model IIRC.

A failing pick up coil may or may not completely shut it down depending how it's failing.Quite often yes that is the case. But It reads the leading edge of the signal block on the flywheel for timing , but also looks for the trailing edge and by the amount of time between front to back edge is engine speed for tci to know how much to advance. It need a crisp signal to send and may not read good at certain rpms. I believe there is more to it than that but I'm not great on these electricals. I'm leaning away from this being the cause though.

By the way it will run on choke , even if it is warmed up ,isn't quite right. They should sputter, spit, and flood out rather quick when warm . The newer CV and CVK carbs have enrichment circuits rather than chokes so they add air along with fuel , those will run at a much higher rpm when "choked" , but these carbs don't , unless the newer versions changed , all of mine shut down if I pull the choke and are flooded when warm. We don't have the newer carb over here so I don't know if they changed , someone over there know ?

Sounds like an ignition advance problem to me. (assuming you've done a proper job on the carb - You've swapped everything else you can... Check your coil wires are on the right way around if they can be swapped.)

That can be caused by the pulse generator or the CDI/TCI

An ignition timing gun is only £25 on Ebay. It's not hard to check.


Any engine work carried out ?? Cam timing okay ?

I think the most likely culprit at this point is the TCI, if the bike runs the same with the new carb, then I can almost certainly say it's the TCI.

I think you are right, it should be the TCI, the resistances on the pickup coil seem within spec. So at this moment of time I'm pretty convinced it's the TCI, but obviously that's just guess work, I'll see if I can find a timing gun, my finances are running low for the month.
Would the coil really have the engine running so bad ?
Would it not just..not run if I had the wires the other way?
What do you mean by cam timing ? I haven't opened the engine apart from the head cover, that was to change the oil seals on the valves, because it smoked on start up. I haven't messed about with anything else in there and I changed the oil after I worked on it and made sure nothing fell into the engine.

I have TCI box for you, but iam in Norway so if you are close come pick it up :) So you changed valve seals without removing head, what tool for removing springs? compressed air in chaimber?

Thanks for the offer hahah :D....but we have just a little sea separating us :D
I'm in Scotland ^^

JJ

just found out Tiggs, on the adv forum, had a similar problem although his was quite severe...I'll try and ground it and see if that changes/improves anything...it's worth a try

Also did you ever start/complete that build you were talking about back in 2013?

Also happy Valentines everyone!...hahahah...I'm so alone..

Back in the old days the distance between us was no problem, so find a boat and do like the vikings:welcome:

Sounds to me like you have checked out the problem in a logical way. First, carb and fuel/air supply. At one point even changing the carb completely only to be left with the same problem. If it was air/fuel supply, the symptoms would have changed measurably even if the problem remained. So, assume it is NOT the carb...

Next logical thing to troubleshoot is the electrical system. You replaced the coil, reg/rect, spark plug, leads and pretty much everything else in the ignition system. This also made no difference at all.

As the problem occurs in the rev range when ignition advances, anything that controls advance could be the culprit.- TCI and also the sensor in the front of the stator. Many TCI/CDI systems have 2 circuits (one for retard and one for advance) rather than an actual curve, so there is one possibility (dead advance circuit in TCI or the sensor which is part of the stator). Me - I'm too dumb to bench test a TCI so replacing it with a known working unit is the best option.

A left field suggestion...
1. a rat may have crawled up the exhaust pipe and died. It's amazing how much crap a family of rodents can pack into an exhaust pipe. This will have the effect of reducing the amount of exhaust gases that can leave the system and has a similar effect to limiting the air inlet. This happened to me when I restored an old Yamaha XS750 (with straight-through pipes). Had me absolutely stumped why the bike would not run. Took of the pipes and extracted about 10 litres of "rat house" from the straight-through pipes. After that the bike ran flawlessly.

I wouldn't miss an opportunity to wear a funky hat and kill in the name of Odin hahahah bier

Wow thanks for the compliment, I feel all clever hahahah...
Anyway I did the final test today with another pair of carbs, same problem...
So as the process of elimination, it must be the TCI, since the pickup coil seems within spec...
I'll order another TCI after the carbs have been returned.

Also an interesting test I did, after the comment on having the wires for the ignition coil the opposite way around.
As it turns out, for me at least, no matter which way I switch the wires on the ignition coil, I'll always get good spark hahahah, don't ask me why that is or if it will do something to do coil, idk :innocent:

I hope you can entertain the rantings of an old grumpy rider. First, check the pipes. This is cheap. Bite me, I'm dutch, and do not like to spend money...

THEN try with a working TCI (better if you can borrow one but you might have to buy).

THEN, think about the stator assembly and try another one.

You will notice I have ordered my diagnostics according to cost. Refer to my initial statement...

Aloha and enjoy the journey

Sorry, I forgot to mention, I have actually had the pipes off multiple times. I'm a 100% certain they are clear, I've had all the sections off too and its an aftermarket exhaust too. I had to weld extensions to the engine studs so I can mount the pipes properly. I couldn't get the studs out because my welding skills are not great, but I did manage to secure the pipes on good. They've been on there for the last 7000 miles ^^
Also the bike hasn't been sitting around at all since I got it. I use it as my daily since I don't have a car or another motorcycle.

Does the ECU/TCI for a 3TB model match the 4PT advance curve ? Can you swap the TCIs from the years between 1990-2002 ?
Anyone done that before :?

For instance this one claims to do it all, unless I'm misinterpreting it? http://www.electrostator.com/fr/xt60...re-xt600e.html

Can you use a CDI instead of a TCI ?

I got a hold of a timing light....anyone know how to use it for the XT600 to confirm the TCI?

I figured that if it is the tci then the timing light will not operate as usual when it reaches that rpm range and there will be a difference in the strobe pattern ?

the xt's flywheel has only a mark for idle advance, so even if you manged to see it through the tiny M8 hole while pointing a strobe, it will not tell you anything about the advance curve.

so you need a timing/degree wheel too and attaching it to the crank is not that easy on an xt.... done it to adjust my supermono road racer ignition, but it involved turning an adaptor instead of the flywheel nut, plus some sort of sealing of the oil splashing behind the cover.

but that was worth doing in a very highly tuned motor. the stock TCI ignitions are so reliable that you never need to really check timing with a strobe, even less so the advance curve. personally i think that you are barking under the wrong tree.

AFAIK all the TCI's for 1990 and up xt's, including the carb'ed 660's will work. CDI's are a totally different principle, need different flywheel/stator

Thanks for your response! I'll try using the light today and see if that confirms my assumptions.
A few people mentioned marking up the wheel from the Tenere forum, I'll take the side cover off today and visually inspect the stator/pickup assembly too.
I honestly do not know what to think anymore, I mean 3 different carburetors and the same problem persists, so its either the pickup coil or the TCI as far as I understand?