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Poor Mid range and flat spots Please help!!!

Posted: Wed Aug 29, 2007 8:27 pm
by garyp3398
Hi.
Its a 2001 Zxr400 L9.Its got a k&n filter and a full Micron exhaust system.The bike went well before i fitted the above parts but now its really bad.Its revs free enough when stationary but when ur out on the road its got a huge flat spot at 6.000 rpm and it doesnt fell back up to full power untill at least 9.000 rpm.Ive spend a bucket load of cash and its turned out worse than it was before :smt013 .Is there any fixes anyone know or is it a rolling road tune up it needs.Ive thought about a jet kit but i really am stuck.If its a rolling road tune up does anyone know anywhere.Im in Ayr Scotland approx 30miles South of Glasgow.Thanks for any help.

Gary who cant accelerate :smt010

Re: Poor Mid range and flat spots Please help!!!

Posted: Wed Aug 29, 2007 8:31 pm
by carsounds_dan
rolling road setup, with your new breathing mods the engine has less back-pressure so power will be down in certain areas.
cheers
dan

Re: Poor Mid range and flat spots Please help!!!

Posted: Fri Aug 31, 2007 1:21 pm
by zimm
im running a full micron system, KnN and dynojet kit on my L4, cant remember what clip position my needles are on, but one important thing was removing the intake snorkel from the airbox?* oh and im running #105 main jets (standard kehin type, not dynojet).. mines got a lovely midrange, pulls nicely from 6k, and really flies from 9..

*some folks say leave it in, common sense told me to take it out as the KnN only takes air from the sides and blocks off part of the snorkel.. then i just chucked in the biggest jets i had at the time to compensate for the extra airflow.. happened to be fairly close..

best bet ? dynorun :)

Re: Poor Mid range and flat spots Please help!!!

Posted: Mon Sep 03, 2007 10:05 pm
by garyp3398
Thanks for your replies.Ive booked a dyno run.What kind of wee things could i do improve the read out of the run e.g. airbox mods, spark plug change ?.Stuff like that.I just want to make it the best i can.And yous guys must know some wee tweeks???.

Thanks for all ur help
Gary