[mechcyber]

I have a 1998 ZX-6R which once was a race bike. It was converted back to street when I purchased it in 1999. Currently the bike runs great, however won't start up when the engine is hot. The engine will turnover but won't start. I would have to wait 10minutes before I can start the bike again. I changed the fuelfilter, clean the carbs, changed the air filter, and replaced the coolant. The bike still has the same problems. Does anybody have any suggestions?

 

[michiganarft11]

Check your radiator to make sure that it's not all crusty. Check your spark plugs, that shouldn't make a difference, but always good to check.

 

[bud8fan]

could have cracked or fauled plugs :?

 

[twowheelertoy]

A couple of things spring to mind.

1) Check the cranking voltage when it's hot as the battery maybe getting tired and needs time to recover some charge because if the CDI doesn't recieve at least 10.6 volts it wont fire the motor.

2) An electrical component is breaking down when hot, This is not so likely as you say the bike runs fine.

3) Valve clearances !! Fine when the motor is cold but when hot everything has expanded and one or more may be holding open hence the reluctance to start you will have reduced compression.

4) I had a customer with a ZX7R P4 started cold fine but not hot using starter.
It would bump start within 10 ft.. replaced the starter motor and all was ok.. It was breaking down when hot causing extra load under cranking which led to excessive drain on the battery which resulted in less than 10.6 volts to the CDI..!

Hope this has helped more than confused..

 

[Anonymous]

HOT!

I think the last suggestion was right on...IF you have a multi-meter check the voltage when somebody is hitting the starter switch...the battery is the cheapest, and probably the easiest thing to change. See if the same physical size battery comes in a larger Cold Cranking Amp (CCA), and go for it. If it's not the battery, then you're looking at several other things like the starter motor...esp. if it is dragging when trying to start. One other thing you might do is to actually do a compression check while it is hot. It's fairly simple to do...