Bike dies after a run of about 16 miles...

I am assuming that it is an ignition problem, had no tools with me the 2 times it happened. It acts like someone just turned off the ignition switch. will not start right back up however the engine turns over, verified feul flow and is good. After bike sits and cools for about 30 minutes the bike starts right back up like nothing ever happened. Have cleaned and/or replaced all terminals in wiring harness and done in depth resistance checks all throughout. I have checked the pickup coils after the engine has warmed and both check well within tolerances. I an really leaning towards the T.C.I. box as it really acts like a chevrolete with a bad ignition module. any input would be greatly appreciated.
Thanx in advance,
Gary

 

Running out of gas? Gas cap needs venting? Do you have a fuel filter?

Could be your float bowls aren't filling fast enough due to a restriction upstream in the fuel line, and slowly drain of fuel until there isn't enough to run. Let it sit for 30 minutes, and they fill up again.

If it was electrical, I'd suspect the coils, as they are known to crack and then expand from the heat of the engine.

I don't think TCI would give you intermittent problems. When they fail, the ignition just doesn't work.

 

Have done a flow test on gas coming from inline filter between carbs and petcock, found results greatly acceptable. carbs have been chem-dipped, cleaned polished and assembled as per spec. feul flow gets me about a quart of feul in roughly 20 seconds. Vacuum to petcock is at about 16 inches at idle. also have checked feul bowl contents while running through bowl drains via clear rubber tubing and while it does dip about an !/8th of an inch at about 9,000 rpm's when snap throttled, however regains correct lvl within a second or so. I will try replacing coils with those from my 650 maxim and see if that does indeed remedy the situation. I have read an aticle in the archives that describes this situation down to the last detail (with the exception that mine will go much farther) and was thinking that it may be the ticket to having my bike being reliable.
I am including a link to the article for any that are interested. hopefully the coils are the culprit. I will let you all know later tonight after I have had a chance to try it.
http://members.tripod.com/dave_jack/id41.htm
Again thanx for the advice,
Gary

 

Just to keep with the fuel theme...just in case. Is your fuel filter clear? Do you have a bubble in it?

Have you tried to open your gas cap when your bike dies, to check the venting? Just to elimante the simple things.

 

Have you checked your valve clearances yet?

It could be purely mechanical too... tight valves tend to work OK "cold" but then once the motor warms up, not so much.

 

Feul filter is a High flow glass Mr Gasket unit from jegs and it has a small bubble in the upper corner. tank has been cleaned stripped and lined with the "creem" system. the fuel low was checked with cap both closed and opened and also in all 3 positions on the petcock. when the bike died i did check feul and found that if i kept cranking it would flood. (not visually however gas smell was horrible after about 3 or 4 minutes of cranking and when it did start back up it gushed black smoke) on another note i do need to get new seals for my gas cap as it does leak after a fill up when shaken.

 

also-

Did you "wet-set" your float levels to spec?

 

I have the same problem and I checked and I found that im losing spark... I think mine is the TCI also because there are 2 coils and if one was goining bad wouldnt you still get spark on 2 cylinders? It would be realy weird if both your coils went out at the exact same time...Anyone know of a way to test your tci box on these things?

 

Have you tested the side stand saftey circuit? It is a common problem and your symptons kind of point to it.
A faulty relay will cause your problems.

 

Fuse box? I had a fusebox problem shut mine off one time as if the kill switch was hit. Was the first thing I checked--easy to check, in my case the neutral light wouldn't come on when it was in neutral.

In most cases a fuel problem doesn't just shut you down the same way an ignition shut down would, it kind of sputters to an end.

I feel like it's worth mentioning that for the last several months I've had an intermittent of varying frequency (from once a day to once every 3 weeks) that will shut my bike down about 2 miles down from first take off of the day or so, and after a while will start right back up. I've gotten good at it and now, since I'm usually on the highway when it happens, will just pull in the shoulder and coast for 30 seconds on the clutch--then, I shift down to 4th, release the clutch, and the bike 'bump starts' and is fine. Will be fine the rest of the day. Can't figure out what it is.

Before I got used to it I used to park it on the shoulder for a minute or two, and then it would start up fine. I thought it might be petcock for a while (bowls emptying, then filling up? fits the 2 mile zone, not so much for yours) but I have a new petcock and problem didn't go away. I suspected TCI, but decided that didn't make enough sense in the end. I do have a spare TCI, I guess I could try it for a month and see if it goes away or not. Some people do describe symptoms like this (and yours) and claim it to be TCI, so it's hard to say.

Best of luck. Try sooner than 30 minutes, say every 5 minutes or so, and see how long it really takes to start again. If I don't wait 30 seconds-1.5 minutes on mine, it will give zero response, but if I give it the time it needs it will start right up like there's no problem.

 

Hello everyone.
Thanks for all the sugestions. Well I have had a few days to test this and check that with the bike. Still no closer to getting it right. I have changed out all of the old relays and just for grins and giggles bypassed the kickstand safety switch to no avail. however I did get lucky and have it do this to me 4 more times except this time i had test light, multi meter and spark tester with me. I am losing spark to all cylinders until the bike cools off. I timed 3 of those times and the shortest was 25 minutes to 34 minutes before it would start again and if I take off again immediately it will die again in a few minutes.... 4 to 5ish. I have cleaned all terminals and or replaced them and checked ohmage throughout the complete circuit for the ignition system and all safetys. checked for pulses coming from ignition pickups and both were sending pulses as per spec. also borrowed a set of coils from a known good bike and still the same result.

i really am looking for any other way out than replacing the ignition module. does anyone have any more ideas?

 

I have been having a similar issue with my 81 xj650, i originally found a bad connection at the fusebox and repaired that, however the itermitent cutout (like turning off the ignition) persisted. I have a testlight installed spliced into the power wire at the TCI and it stays lit when the vehicle dies. I have no spark when it dies and the pick up coils and associated wiring check ok, although i havent been able to test them when it has failed since it has been brief and infrequent (sometimes it immediately restarts and sometimes it takes 5 mins) Never has it left me stranded for more than 10 mins, I have a spare module now (thanks Abeja) and i am in the process of testing it on the bike to see if the problem reoccurs... I'll keep you posted. My setup is stock and original, as far as ignition and wiring goes... headed out for a ride.

 

Sounds like something is getting hot in the TCI and going open. Wouldn't hurt to pop the cover off and inspect the board real good.
We test boards like that with a hair dryer. Get the bike running and warm up the TCI and see if it kills on you. Then if it does turn the heat off and blow cool air on it untill it will fire up again. Pretty much narrows it down.
Do the same with the pick up coils and see if they act up when warm.

MN