hey guys, the other week my bike started backfireing and wouldn't really rev above 10 000 rpm whilst riding. i figured that it was the fuel filter so i replaced it with a new one, which was more labour intensive than i thought it would be. That seemed to improve the situation a lot, it stopped the majority of the backfiring but it still doesn;t want to do much above 10 000rpm whilst riding. Now to my question, would replacing the air filter rectify the problem?? the old one is in bad shape so it has to be done anyway so i have one coming in on friday. what had me confused was the fact that his came on really quickly, it went from good to bad in about 2 days, any ideas why ? cheers
could possibly be a bad batch of fuel (Have you filled up since it happened? don't use shell optimax - i reckon normal unleaded 95 RON is fine) Otherwise maybe the air filter (worth replacing anyway, should improve engine running if the old one is stuffed) but it seems weird that it went downhill so quick. Other options i can think of would be spark plugs or ignition leads or something wrong in the carbies. Hey i'm no mechanic, hope that helps a bit!
Are you meaning when you rev it beyond 10 000 you don't get much power at all? Or can it not rev past 10 000? If there just isn't a power increase I am stumped. If it can't rev past 10 000 then it could be something to do with the exup not openning (as it usually opens in that range).
when i said it wont do much over 10 000 rpm i meant that there is very little power there at all, if any and once you hit 10 000rpm it takes a long time to get to say 14 000rpm, it feels very restricted. i checked the plugs when i replaced the fuel filter and they were black, but that could have been caused by a lot of low speed riding that i had to do to get my P's.... yay i got my P's... but i replaced them not long ago so i cleaned them up and put them back in. the exup motor and cables seem to be turning freely so i dont know whats going on. hopefully this new air filter will come tomorrow and it will rectify the problem, but i will post the results when i fit it
I'd suggest wiring the exup open first (see third post at <!-- l --><a class="postlink-local" href="http://www.fzr250.com/viewtopic.php?t=676">viewtopic.php?t=676</a><!-- l --> ). It is relatively easy to do (don't even have to take off fairings) and if it solves your problem then you know that the exup is the issue. If it doesn't solve the problem then it is only about 20 minutes of your life wasted.
