Advice: Why is my ZX-6R cutting out?

horuson1: I have a ZX-6R C1H (2005). When I go for a ride it seems to be running hotter than it should then if I stop it cuts out unless I rev it. If it cuts out it won’t restart for about 15 minutes (it turns over but won’t fire). I’ve checked the ECU fault log and even a garage has taken a look and can’t find the fault. Please will someone help?

jaffa90: Running hotter is a sign of a weak mixture or coolant not circulating – with all the sensors on modern bikes I’ve no idea. When you try to start it within the 15 minutes and using throttle just have a smell at the back of the exhaust for a whiff of petrol. This should give you and your garage more of an idea.

smidget: Have you or the dealer done a full exhaustive test of the ignition system? The symptoms you describe can be linked to cylinders not firing or the combustion being incomplete, which would also back up Jaffa’s suggestion.

horuson1: Thanks guys. Yeah all plugs changed, coils checked out and ignition appears to be good. I did think of coolant, but that appears to be good. The only noticeable thing was that the fan came on at 98°C and then it appeared to start misfiring and cut out.

jaffa90: It’s possible your fan is taking too much current if the wrong fuse is fitted.

James600zx: If it cuts out and won’t start when hot, that is typical of a bad pick-up coil (aka crankshaft position sensor) although I’d expect a competent garage to go straight for it, so maybe not in this case. If the fan triggers rough running it could be that the bike is not producing enough electricity to run everything. How’s your battery holding up?

I’ve also heard of an R1’s cooling fan blades chaffing a sensor wire and causing problems that way.

horuson1: Thanks for that, the fuse is correctly rated as per the manual. As for the battery I see your point if it was drawing too much current that may kill the battery, but not sure how that affects the overheating issue. But thanks for the ideas.

James600zx: I was thinking more along the lines that perhaps your alternator or reg/rec weren’t doing a proper job, a symptom being that when you switch more things on, like the fan, there is even less current available to run the ignition and the bike runs even worse. That would probably lead to your battery losing charge too though, hence my question. I ignored the overheating!

oscarthegrouch: It could be a weak battery as four-strokes thrive off a decent supply of electricity to power all ancillaries. Get the battery tested properly and also check charging circuit as it could be a reg/rec fault frying the battery.

horuson1: Thanks guys I think the overheating is the first thing to get sorted and maybe that’s causing the other problems.