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Top end power loss

PostPosted: Wed Jan 05, 2011 7:25 am
by desertdance
Hi to all & best wishes for 2011!
There's a pair of ZZR250s (both 2001 models) in the shed: Both used to pull around 160kph.One still does. However, the eldest son decided to use his one without coolant....After replacing holed radiator & stuffed water pump, new spark plugs, oil change and valve clearances, it does everything right: idle, no abnormal engine noises,and pulls cleanly through all gears EXCEPT top gear. It won't budge over 120kph.
Feels like it has a limiter on it.Any advice?
Thanks, Mark

Re: Top end power loss

PostPosted: Wed Jan 05, 2011 11:14 am
by tim
Hope you can work it out sorry I'm of no help.

desertdance wrote:....
Feels like it has a limiter on it.Any advice?
Thanks, Mark


EXCEPT, maybe it's similar to this :D
viewtopic.php?f=48&t=28543

Re: Top end power loss

PostPosted: Wed Jan 05, 2011 11:50 am
by Nelso
I take it he didn't seize the engine when he cooked it? I'd check the compression between the two bikes to see if the overheated one has lost any. It's an easy place to start and will rule a few things out straight up.

Re: Top end power loss

PostPosted: Wed Jan 05, 2011 11:58 am
by desertdance
Thanks Tim.However, I'm not trying to mono a 250 ,just trying to work out what's causing the power loss at full throttle in top gear.
Cheers, Mark

Re: Top end power loss

PostPosted: Wed Jan 05, 2011 12:02 pm
by desertdance
Thanks Nelso, I'll get right on to that compression test.
Cheers, Mark