Dies while riding! Heat related? Patient passengers.

Ok, Im going to describe this problem in the best detail possible, because that will probably give someone savvy the best chance at solving it. But Im open to non savvy responses too because I am willing to try anything just to learn my bike better if nothing else.

I recently got a tune up and carb cleaning, when I bought the bike a few months ago. It wasnt running that well but it got me all the way from pleasanton to SF without a problem. My first time on the road and I took major highways and it was raining, and I didnt have gloves, and I went over the bay bridge in traffic, of course splitting the lanes as we are so lucky to be allowed to do in california. So began the learning.

After that, the bike began to have a strange problem; it would die while I was riding it, a few minutes after beginning my ride (starting up and running perfectly until then) and then would need to sit for a few minutes (3-10) and then would start again, and run for another few minutes, then die again. I took it back to the mechanic because I didnt know what to do and didnt have a place to work on it myself (I was sharing a room in a house with 7 other people and no garage or backyard), and they changed out one of the ignition coils and it ran fine for a couple of days, and then the problem came back, worse than before. Though I should have brought it back to the mechanic, I had it parked in a place where it could sit, because it was raining every day. I let it sit there under a cover, for a month or so. I had it towed to the mechanic, a good one called werkstatt that came highly recommended, and they cleaned it up again and then it ran well for another 4 days. Now the problem has come back. I dont want to bring it back to the mechanic just yet because I think I might be able to fix it myself.

The bike starts up fine, warms up and sounds great, has plenty of power, seems to sound fine to me and others, and all the plugs look just like the healthy plug picture in the owners manual.

So then I start riding, and after about a mile the engine just cuts out. I pull over and start looking at the bike. The exhaust smells normal and not like gas, and when I pull the plugs out, the holes dont smell like gas too much, and the plug tips arent wet with gas. when I take out a plug and hold it to the engine so it grounds, there is no spark! But if I just wait a few minutes, the bike will start back up and run fine, and I can go another mile through the city.

The cutting out happens sometimes when I am accelerating, sometimes when I have the clutch pulled in, and sometimes when I am just cruising at one speed.

Flooding is a reason that an engine might cut out and start back up in a few minutes, and the bike seems to burn a bit more gas than I might have thought, but I thought someone might have another suggestion? The bike doesnt seem to be overheating, but I thought there might be some kind of kill switch that is shutting the engine off to prevent damage somewhere, and I can try substituting parts in the electrical system because I scrounged an entire electrical system off another old maxim 750 that my friend was parting out.

BTW my friend has a maxim 750 frame, engine, gearbox, and other parts in his backyard that he would love to get rid of, in Aptos, CA. just reply to this post if you are interested. engine started and ran fine before it was laid to rest.

Thanks for reading, and thanks for any suggestions you might have!

-Justin

 

Does it die only when it is raining, or with all dry weather too?

When it only occures with rain, i think the sparkplug cables lose current when they are wet.

Try: when it's dry dark, start the engin, till it's runing smoothly. Take a plant-spout, and spray some water over the sparkplug cables. you might see sparks hit over to the engine. when sparks hit over, please replace the sparkplug cables with a major brand.
Had the same problem once with an old bike, replaced the cables with silicon cables of NGK.

 

Just had the exact same problem, most thought it was the fuel tap but it turned out to be the TCI, fitted a new(ebay) one and not had a problem(well cutting out anyway) since.

 

Here's how to check out your TCI:

Go grab the TCI off your friends bike. Put it on yours. If problem stops you know it was the TCI.

 

And of course be sure to ad your bikes model, motor size and year to your signature.

Steve

 

Yep, I'm with changing out the TCI with a known good one to see if the problem goes away, too.

 

ok Ill change the TCI and then Ill let you know if it works. And I want to try to lighten my mixture but I dont know how to do that, I might just have the mechanic do that.

 

ok, TCI is changed. of that little assembly, there are three parts. The black box, which is the tci I guess, which I changed and am about to go for a ride with, the metal thing that gets hot and has one plug, and another small metal box that has one plug of wires. What are those things? Should I change them all at once?

 

Welcome Justin,
Changing multiple items at once will mask the problem. You will only find what causes the problem by replacing one thing at a time.
Change the TCI (little black box w/two plugs). Test. Problem gone? You found your problem.
My second suggestion is to check out your ignition pickup coils. Make sure they ohm out correctly. Heat will cause them to drop. Typically when they die, they stay dead but that isn't always the case. My money is on the TCI. It can be rebuilt and they do have a tendency to suffer cracked solder joints so pop it open and touch up the solder runs. The capacitors in the TCI also like to drop dead, consider replacing them. There was a write-up in the last two weeks on this topic, look around the archives.
The metal box w/one connector is your voltage rectifier/regulator. This will not cause your problem.
The small metal box w/a bunch of wires is a relay for some system on your bike (I'm not 550 savy so forgive me). It won't cause the problem you are experiencing either.
Buy a manual for your bike. Best investment you will ever make. Saves money and trips to the mechanic.
Pleasanton to SF, in the rain w/out glove splitting lanes across the bay bridge is riding on the risky side. Have you taken a rider safety course? Highly recommended and also worth every penny. Always good advice to start off right and learn good habits rather than try to break bad ones.
Lastly, and I don't want to steal Rick's thunder here, check your alternator brushes. Another wear part that goes un-noticed on our beloved XJs.
Welcome to the fold.

 

it worked! I just replaced it and now it works great! We rode around the presidio and to the beach and all is well. Thanks for the suggestion micarl and acer!

 

please post results of your test ride, I'm having a similar problem.

 

edit, guess I posted a little late. Thank you