No one knows how to fix this problem

[Riddellw1]

So I've been on here, craigslist, and meeting experienced professionals in person, and nobody knows what the problem is here.

My motorcycle RANDOMLY shuts off, any given time. It does not bog down, it does not sputter, it just immediately shuts off at random times. Sometimes I'll go a couple of days and be able to ride it WHEREVER for however long I want, and there won't be a problem, and then I'll wake up in the morning, go get on it and five minutes into the drive it shuts off.
I don't know why I'm continuing to post on here for help, because literally no one knows how to fix this.

THINGS I HAVE DONE:
-Completely replaced the fuse box, and all connectors on it, to the modern "blade" style fuses.
-Cleaned the contacts under the ignition button with sand paper, and made sure the ones under the killswitch were clean as well.
-Checked the ignition coils for any problems as best as I could
-Cleaned the spark plugs, and also used different ones to make sure the wires were working properly
-I've taken the kickstand safety relay off, and it has still stalled with it off, so I put it back on.
-Fiddled around with literally every connection while it was running and none of them made the slightest sound or error.
-Taken the headlight off, checked all connections in there, they're fine as well
-New Battery


Any ideas? Or is everyone else as stumped as I am. This is impossible.

 

[drewpy]

diagnosing bike problems up to 5000 miles away, can you not blame us for not being like a local mechanic?

we try and help most people, but if you don't know why you post here because we can't help, sounds a bit ungratefull

as with all random problems, the only way to crack it is to check sparks and fuel delivery when its misbehaving.

Is it points model, could be the condensor is breaking down. check for sparking across the points ( there shouldn't be any)

 

[leedutcher]

hyjack sorry! so there shouldnt be sparking?

 

[hmusket]

Sometimes the problem goes beyond the explainable and you need to call a professional in.

Seriously though, as Drewpy said, we're giving as many ideas that we can think of, based on what you're telling us. They may or may not help, but they are worth checking out. Your TCI could be defective, your regulator/rectifier may be shorting out. Maybe there's a frayed or broken wire in your wiring harness.

There are ways to test everything electric and electronic on your bike. I posted a link to an online manual for your year bike in one of the other 3 threads you started. If that manual is not enough, here are some links to ebay auctions for service guides:
http://cgi.ebay.com/ebaymotors/1982...Motors_Manuals_Literature&hash=item1c1f14d21f
http://cgi.ebay.com/ebaymotors/YAMA...Motors_Manuals_Literature&hash=item588fbbad46
http://cgi.ebay.com/ebaymotors/YAMA...Motors_Manuals_Literature&hash=item43a814a03b
http://cgi.ebay.com/ebaymotors/1983...Motors_Manuals_Literature&hash=item2eb38a1f40

Since very few of us on the forum are professional mechanics we do the best we can from the years of experience of trying to keep our rides going.

Good Luck.

 

[XS-Time]

Like Drewpy said "Hold the bike closer to the screen so we can get a better look."

But seriously, you sound like your on the right track. You are doing the right things.
No one here will be able to tell you "how" to fix it. It is a process of elimination. First of all you need to tell us the make and model of your bike. That makes a lot of difference. Then when it does quit again write down the conditions, is the bike hot/cold is it wet out, was the bike under load or was it idling Ect. How long till it starts again?
The way you describe it with it just quitting with no chugging or sputtering, it sounds electrical . Maybe your TCM (if equipped ). It does sound like you have checked the kill switch but it might be worth a second look.
Sometimes we overlook the obvious because we think the problem is complicated. Many people have tried to track down an ignition problem when there tank was empty. It's embarasing but it happens to the best of us. Just take your time and think it through.

 

[darkside]

sell the bike. buy another one that dosent do that.

Posted via Mobile

 

[bcware]

I would immediately suspect the wiring harness. A wire or contact could be corroded. This type of troubleshooting requires a lot of patience and time. Closely inspect every wire and harness, but there is always the chance of electrical tape covering something up.

 

[Maxim-umm]

As many have stated, it sounds electrical. You could remove the safety relay under you seat to help diagnose your problem, just make ABSOLUTE SURE you're in NEUTRAL when you start your bike. This helped me when trying to diagnose my electrical issues. But honestly, I think your best option at this point would be to either replace the whole harness or rebuild it with new wires. It sounds like there is a wire that is corroded/broken INSIDE the insulation where you CANNOT SEE or REACH. Before replacing/rebuilding you could go through the whole things and check the continuity of EVERY wire. This will be a long and very time consuming endeavor if you decide to try it. Not just clean the connections, but connect your meter to each end of the wire and wiggle it. If the signal cuts out when you wiggle it, there's one of your problem wires. There could always be more than one, I found 3 when I checked mine. So, be patient, methodical, and enjoy the adventure

 

[hoganJr]

Nothing is random. You need to systematically troubleshoot.
When it dies will it still crank but not start?
Is there fuel in the float bowls?
Do your indicator lights come on?
Have you eliminated the ignition switch and connections?
Is your gas cap venting?

hoganJr

 

[Riddellw1]

Hey the make and model is 1982 Yamaha Maxim XS400.
And when I said I don't know why I'm posting here because no one knows how to fix it, I meant, I won't be able to get all that much help because this problem is too difficult to fix through a computer screen, no offense to you guys. I'm just taking it into account.

The gas cap is working properly as far as I know, theres a little bit of a leak but oh well
When it dies, it cranks the second I want it to, it just doesn't start up.
There is fuel in the whole system, there is no fuel problem, I've checked what I could
The lights come on (Neutral, oil, highbeams) even when it dies, same with the headlight
I've sanded down the contacts for the ignition switch and I've checked the killswitch, they work properly.

I've been through all obvious connections and cords, they're all intact and moving them around does nothing
I've replaced the fuse box

Darkside, I am contemplating selling it and buying a new one, however, I'm very stubborn and really dislike not being able to fix things, so most likely I will be working on finding this problem for years before I actually sell it.

 

[63-Coupe]

At no point here have you confirmed to us that the plugs are actually sparking. Next time it does this pull one and crank the engine to see if there really is spark at the plug itself. If no spark then start working backwards from there.

 

[striker85]

When I was trouble shooting the non-functioning headlight on my wife's XS, I had read about the relay that switches with the ignition and was ready to start cutting and all that. But when I looked at the schematic I saw this random diode in like. I unwrapped the harness and found this lonely diode in the middle of the bike which had a lead broken off. I solder it back up and everything works like magic.

Moral of the story: as was mentioned, look at the schematic, rule out variables and expect the unexpected. It is not impossible to have a wire rubbing on a frame member for what would seem like no reason. Be diligent and you will find it. From the symptoms you describe, I would bet on it being something like a wire that is grounding out randomly.

 

[Kithegearhead]

Hello

I would check the wires that connect ponts to the condencer, especially right at the points cover grommet. Strip the external insulation, you can always replace it with srinkwrap. The insulation around wires cracks and in the humid mornings plays tricks with shorting to the ground, causing a shutdown. Then when the bike warms up and dries up it runs like a charm.

hope this helps. i will try to take pictures this weekend

 

[OnePhate]

It could also be loss of ground. Sounds like a crazy problem, I'd probably going nuts right now if I were you. I'm going nuts over a carb issue that I can't work out.

 

[lhaolpa]

This might be a good time to invest in a "cable tracker",I got one from Harbor Freight and it works pretty simply. You simply attach one end to one end of the wire or circuit,and ground the other,and move the "beeper"along the circuit in question.When a short is encountered,the pitch changes and gets louder as you get closer.They are pretty inexpensive and really work,at least the one I bought does. good lucl lha

 

[cmoore352010]

Definately sounds like a wiring issue. I would definately be checking every wire thouroughly with a multimeter at the least. lhaolpas idea is great and probably a time saver. i am going to get one to use myself.

 

[wedge98]

A buddy of mine had a bike that would randomly blow fuses, turn off, etc... The problem was traced to multiple wires which had been pinched. Basically his entire wiring harness had to be checked until the found all the issues. After the wires were replaced, the bike ran perfect with no more issues.

It's painful to do but if you find just one issue it was worth the hassle.

 

[leedutcher]

^ it may seem like its going to be a nitemare but it really isnt to bad...just start from the top and work your way down of the wiring harness

 

[Gabys79]

hijack -- Have the wiring harness off, would this be a good time to just check it? If so, with what? Or would it be better to it completely?

 

[226dark]

This thread needs to fizzle and fade away; dude has not updated for 2 weeks and has 10 posts. He posted to whine about something he obviously needs a mechanic for if it's to change a fuse.