Bike idles down and dies once it's warmed up

[grendel]

Thanks for the replies, Smiley. I'm gonna try to make some headway on your suggestions today.. looks like the constant rain we've been having might actually stay gone today!

[Black Lightning]

I don't usually recommend mechanic-in-a-can solutions as they rarely work,

"Mechanic in a can" stuff is useful as a maintenance item. It won't solve a problem that has resulted from age or some such but if used sparingly on an ongoing basis it can help keep things clean and running free. Help mind, it is no substitute for proper maintenance.

[grendel]

I woke at 4am this morning and realized that I had a similar problem with an '86 Concours. It would run fine and then quit until cooled off. It turned out to be the ignitor (black box ignition). It was giving a spark but it was a weak yellow spark when bike would not run. Eventually it quit entirely, 200 miles and a ferry ride from home of course. Swapped it with one off another bike and it ran fine. Bought one at bike wrecker for around $80 and it never let me down again.

Maybe you could borrow an ignitor box to see if it cures problem?

Well, I started it up and let it run itself into death (urgh) ... then quickly pulled the plug wire from the plug, attached it to the spare plug I have, grounded it against the engine block, pressed the starter and... nothing.

No pop, no spark. Nothing.

I don't have anyone I could borrow an ignitor from, but would I maybe be able to do anything to 'resuscitate' mine? Failing that, are these things pretty standard from bike to bike, or are they specific to the make/model?

[Black Lightning]

I don't have anyone I could borrow an igniter from, but would I maybe be able to do anything to 'resuscitate' mine? Failing that, are these things pretty standard from bike to bike, or are they specific to the make/model?

If the "box" is all sealed up, or, worse yet is encased in a block of plastic then you will most likely have to find a new/used-but-good one. If it looks like you can get at the insides then you might be able to fix it. I'm betting it's largely solid state which means it's most likely cratered. The good news is that Kawasaki tends to use things for more than one bike and they also don't tend to change things much unless they absolutely have to. First off, check with the local Kawasaki dealer. If nothing else they can tell you how easy it is to find new parts and, since used bike parts places tend to charge about half the price of new parts, this will tell you roughly how much it will cost to replace. Then check the yellow pages for used bike parts places, or on line. Bike Bandit is the only place I can think of off hand but there are lots around. Some of the web sites you've already looked at might be of some help too. Some enthusiasts have extra parts laying around they will part with for a small amount of money plus shipping.

It would help if you can find a part number. It might be embossed on the box someplace. If not, see if you can find a manual on line. You will want the workshop manual and, if it is separate, the parts manual. They are quite often available in PDF format.

Good luck.

[Smiley]

kawasaki.com On the left side "owner info"> drop down shows "parts diagrams" > quickest to enter VIN and you might be lucky and they still have that model's parts diagrams. When you get the part number the rest should be easy. Kawasaki are pretty good at supporting old models and BL is correct about using the parts for several models.

The ignitors are not rebuild-able, the "J-box" (junction box for all electrics) are rebuild-able, usually by a simple re-solder.

When it won't re-start do the lights, horn, signals etc. still work? If so, the J-box is fine. I still suspect the ignitor but it's all a WAG on my part. Let us know.

[FROSTIE]

I think the choke cicuit is staying on that is why after it quits you have to open the throttle to get it to start.

[Sportbikecalgary]

I think the choke cicuit is staying on that is why after it quits you have to open the throttle to get it to start.

I tend to follow this line of thinking. Work on everything mechanical before going after black boxes. Maybe the cable on the choke slipped a bit after you installed it. Try removing the cable once again and doing the actuation manually see if it makes a difference. As for the weak spark, your ground area might not have been ideal . Do you have the correct spark plugs? gapped properly?

[grendel]

When it won't re-start do the lights, horn, signals etc. still work? If so, the J-box is fine.

Yes, the headlight still works. I didn't really pay much attention to the other components you mentioned - I'll check that this evening and report back.

Maybe the cable on the choke slipped a bit after you installed it. Try removing the cable once again and doing the actuation manually see if it makes a difference. As for the weak spark, your ground area might not have been ideal . Do you have the correct spark plugs? gapped properly?

The choke is just a lever on the carb itself, so there are no cables to mess with. When I had the carb off the bike, I worked the choke lever and verified that it moves things (shutters, almost) on the intake side of the carb. Nothing seemed to be stuck or gummed-up-feeling.

Spark plug is correct as named in the manual, and I did gap it to spec before installing it.

[Sportbikecalgary]

I'd be looking at the carb. Sounds like it's gummed up, as in the fuel isn't filling the float bowel fast enough and the engine is starving for fuel after draining it. If it's filling too slow, then it would makes sense that after a few minutes it's re-filled enough to allow the engine to start again.

Going back the this comment... my old 78 KZ 650 had a prime setting on the pet****. (main, reserve and prime) Prime was a straight gravity feed from the tank. What do you think about putting it into prime and seeing if it runs out of gas. If the carbs were gummed up, flow would still be restricted, but the Prime setting would be the way to get the most fuel you could into the carbs. I think this would be yet another test down the inaccurate float bowl level path.

[grendel]

Going back the this comment... my old 78 KZ 650 had a prime setting on the pet****. (main, reserve and prime) Prime was a straight gravity feed from the tank. What do you think about putting it into prime and seeing if it runs out of gas. If the carbs were gummed up, flow would still be restricted, but the Prime setting would be the way to get the most fuel you could into the carbs. I think this would be yet another test down the inaccurate float bowl level path.

On my bike, I have ON, OFF, and RES - I tried on both ON and RES, and same result - there doesn't seem to be any advantage to one over the other, as far as the bike dying.