Runs when it wants

My KZ1000 has decided to run only when it wants. It will start very easily when cold (rich maybe) and once it warms up a little it dies. I have tried very much to adjust and get it to work but I have to leave it until it cools back down. With the air mixture screws nothing seems to make a difference. Once it's warm, it will only idle poorly with the idle screws nearly all of the way out but giving it throttle is a no go. It also backfired this way. It does seem to flood easily but then it will act lean. Could some of my floats be dumping too much fuel all of a sudden? Or does this seem like an electrical problem such as the coils have become weak and get weaker with the heat? In what way would I test the coil to make sure they are up to par? I couldn't even get it to move yesterday because it would choke out and die.

I'm almost to the point of selling it for scrap steel.:ohmy:

I'd look at the valve clearance, if you haven't.

Plus also a good carb cleaning would be adviseable, to the point where you pull them off, tear them down, and blow out all the passages.

But I am betting on valves if you haven't already checked them.

Coil test: I am pretty sure that between the positive and negative post you should read between 3-4 Ohms, and between the plug wire hookups 12-14 Kohms. The plug caps I believe should be 5 Kohms each for your bike.

But check the valves/ get the valves checked. If you have already done that, then we can look other places.

Valve job has been done. It has had seafoam ran through it. Drained the fuel bowls and so on. I may just rebuild the carbs that way it will be done.

can you get a plug reading after it quits running? i know you supposed to do it under a load and wide open throttle but at least you can see if it has gas on the plugs..i would guess jets are clogged up and your running on the choke till warm

It just started this recently which is why I don't understand it. I'm going to pull the carbs this weekend and clean and check float levels. I've also got a whitish colored smoke coming from the left exhaust. That's never happened before either.
What parts do I need to get if I pull the carbs apart for cleaning?

Pull the vacuum line from the back of your petcock as well, make sure it's clean and dry. If it starts leaking, pure un-atomized fuel will be sucked right into the vacuum of the carb boots and into the cylinders. I've only seen it happen once, but I've heard about it happening countless times.

Alex_KZ1K wrote:

Pull the vacuum line from the back of your petcock as well, make sure it's clean and dry. If it starts leaking, pure un-atomized fuel will be sucked right into the vacuum of the carb boots and into the cylinders. I've only seen it happen once, but I've heard about it happening countless times.

I've had it happen to me. My bike ran like that when I got it, and it ran similarly to what you've described. Once it was good and warm (5-10 minutes of idling, with me fiddling with choke and throttle a lot of the time) I'd rev it to about 5000 rpm and pull out sloooowly. Once I got going, though, usually things were reasonably okay.

If you find that this is your problem, it's probably worth an oil change. I had gas in my oil after running the bike like this, and I can't imagine that's a good thing.

I just rebuilt the petcock due to the diaphram going bad. That part seems to be working fine now but I will double check. I'm about to try and remove all of the carbs. Wish me luck.

Alright, got that done now. Carbs look to be good and clean. I will break them down more on Friday for closer inspection.

Post edited by: pidaster, at: 2006/02/16 18:14

The previous owner of my bike had just rebuild the petcock, too.... It might be a long shot, but it's easy enough to check.

G'luck!

what about the fuel filter, if new is it on the right way? limiting the gas flow

No filter right now.

It sounds like a carb problem. I'd get some kind of filter on there. It doesn't take but a tiny speck of something to clog up a port in the carbs or hang up a float valve or whatever.
WiredGeorge? He'll have seen this and hopefully will comment on it!