at about 7500-8000 rpm in any gear only at 85% or more throttle, the bike loses power. it seems like i have a misfire like i droped a cylinder or something. if i back off the throttle it doesn't do it anymore. i already tried replacing the spark plugs and that didnt make a difference. i'm trying to distinguish if the problem is fire or fuel. it just started doing it about a week ago. the bike is a 94 f2. thanx for any ideas and info you might have.

-Rodney

 

I had this same problem with an F2 that I bought used. I finally fixed it by installing a Dynojet and installing bigger jets than what came with the kit.

 

My guess would be that you need to have your carbs looked at. Maybe they just need to be re-jetted, cleaned or overhauled.

 

thanks alot i gonna give that a try. thanks again
rodney

 

first things first. As an engine increases in speed, it requires a greater flow of fuel. Firstly remove the fuel filter (located in the fuel tank, under the petcock) check the screen for silt build up and clean. This must be checked before you go pulling down carbs or you could waste a days work for nothing. Also check the fuel tank breather lines for blockage. This can also restrict the flow of fuel to the carbs.