ZXR400 L9 running on 3 after hitting rev limiter

[ROUTY]

Hi
My ZXR400 L9 has started running on 3 cylinders after hitting the rev limiter. I use the bike for racing and trackdays but it is a standard engine with no mods. I have had new plugs fitted, carbs balanced, valve clearances checked and compression checked. It did fix the problem but as soon as i hit the rev limiter it loses power when the rev's come back down (which it didn't use to). Has anybody got any suggestions on what could be causing the problem and how to fix it . Any help would be much appreciated.

PS Don't say don't hit the rev limiter

Cheers

[parby81]

personally,

I'd whip the fuel tank air box etc off and identify which cylinder isn't firing. Then check for a spark on this cylinder and probably a compression test. Then go from there dependant on results

[ROUTY]

Thanks for the reply
We've tried that so now we've got another ECU and coils so hoping that will sort it out. I will find out in a couple of weeks
so fingers crossed
Thanks again for the reply