Bike starts and runs...only if I keep starter button pushed

I love my motorcycle, a 1982 XJ 650, and I really like this forum. But I'm an idiot and I can't figure out why the bike starts and runs - but only if I keep starter button pushed. It will crank but won't stay running unless I hold in the button. It dies as soon as I let off. I've bypassed the button completely and the bike starts and runs perfectly when I turn the key. But the oil light stays lit, of course. Can anyone help a brotha out?

 

Sounds like a bad connection somewhere. check the wires down by the starter solenoid, clean & your ground connection to the frame. Check your fuses to see if the clips are bad in the fuse box.

 

I'd start by carefully disassembling the right hand switch cluster and diagnosing your problem. Remember the "run-off-run" switch is right there with the starter button...

 

Re: Bike starts and runs...only if I keep starter button pus

I think Fitz is right, start in the right hand control here, looking for short, loose connection.
Who knows maybe while pressing the starter button it moves a loose wire on the cutoff switch just enough.
When you say bypass the starter, you have taken the right hand controls apart and jumpered the starter switch?
Does the starter disengage?

Isn't there a latch that keeps the starter from being engaged while the motor is running?
All though if you are holding the starter button in and the starter is disengaging it would appear that it is working correctly.

 

Re: Bike starts and runs...only if I keep starter button pus

Thanks for the quick response. I've permanently bypassed the run/off/run switch (connected the two wires) so I don't think that's it. I've currently got the two starter button wires connected as well. The starter dissengages once the motor is running, as it should. I'd just like to get my starter button working again and I'm also wondering if I'll mess up something else if I run it this way. The fuse box was rewired with new modular fuses...nice. I'll check the connections around the starter relay.

 

I agree with Maxims, but my only question is doesn't your starter motor keep running when you hold the switch in, Id check that cause you will have to replace that in no time at all if that is the case.

 

Re: Bike starts and runs...only if I keep starter button pus

Nope, starter motor doesn't run once engine cranks. Aren't they supposed to dissengage?

I just got back from a 25 mile trip and the bike started and ran fine. I did notice that the oil light dimmed each time I pulled the clutch to change gears. Is that normal?

 

Re: Bike starts and runs...only if I keep starter button pus

The starter should not engage while the motor is running
Oil light should not be on.
The light comes on when there is no oil.

 

Re: Bike starts and runs...only if I keep starter button pus

Well, then I've definitely got two shorts somewhere. When I first bought the bike (used/thirdhand) and the starter button worked, the oil light would come on when I turned the key but then would go off once the motor cranked up. The bike had other electrical issues but they all disappeared after I rewired the new fuse block.

Is there any harm in running the motorcycle this way? She is my preferred form of transportation. I'd hate to keep her in the garage just because I've got a pair of shorts...sorry, I couldn't resist the pun.

 

Tiki, Spend about an hour of your time just going over all the grounds and connectors in the head light and under the tank. Check to see if there is any green fuzz on or in any of the brass connectors inside of those plugins. If that all looks ok then there are a couple of other things that could be a problem, lets start with the basic good connection check first. Make sure your main engine ground is solid too. There is a screw with a bunch of ground wires under the tank also, remove and clean those . Time and mositure is the main reason for electrical failures. You might even find a burn't connector in there somewhere.

 

What's happening here, is that you don't have 12v to the ignition circuit when the engine is in a "run" condition. You only have it when the engine is in "start".

I had this happen on a car once, but it's a little more thought to work it out on a bike because you have a starter button instead of a "start" postion on a key switch.

Remove the bypass wiring you installed, put the key to "run" put the kill switch to "run" and check for 12v going into your ignition coils. You will find that it is missing.

In fact, now that I think about it, the problem may be a faulty ground or an open circuit related to your kill switch.

 

Re: Bike starts and runs...only if I keep starter button pus

I didn't notice; did you say somewhere which XJ650 you have? J, RJ, H, etc? I think they're all the same for the start and run circuits, but it would be helpful to be sure which model we're talking about here.

The starter switch, on the XJ650 diagrams that I looked at, does not provide 12V anywhere, per se. It simply grounds one end of the starter solenoid, engaging it. That grounded line (L/W) also runs to the diode block, though. A bad, missing, or mis-wired diode block would be a likely candidate for strange behavior.

 

Ok based on that, 12v to the coils is routed through 2 places- the key and the run/kill switch because turning off either of those on a normally running bike will kill the engine.

The question is, how is 12v being provided to the ignition when the starter button is pushed? Is it via a diode?

 

Re: Bike starts and runs...only if I keep starter button pus

There are different diode blocks on the different 650 variants. Definitely need to know which one we're talking about before going further down this path.

Interestingly, though, the Oil light gets its 12V supply from the same line that powers the coils (R/W), and gets its ground through the diode block. I doubt that's a coincidence.

 

Sounds like a diode block/connector problem to me?