Hey I am new to this site and need some info. I have a 1986 250 quadracer with everything stock except fmf pipe and silencer......I am going to be getting it rebuilt .30 over with weisco pistons.......boyseen power reeds...k&N air filter. i live in new jersey. Do you think i will have to rejet and if so what to.thanks

 

Call FMF. They should have the jetting specs you require on file.

Joe

 

You may have to jet up just a bit, I take it you are running the stock air filter right now? IS the jetting spot on before the upgrades are performed? If you are just going up to .030" over and adding the reeds and filter then you should need to just fatten it up a bit.

 

right now i have a uni filter and the fmf pipe with no jetting done. when i go and rebuild it with .30 over with weisco pistons.......boyseen power reeds...k&N air filter how many sizes do you think I will have to go up????......And if i take it to the extreme and have my head polished how much more in jet size will i need to go up.........will i need to run race fuel also??

 

Not a huge difference in air flow between the K&N and the UNI, personally, unless you run in the sand, keep the UNI as it will protect your engine a bit more. My concern is if you have the FMF pipe on and never rejetted, you are already running way to lean. Call FMF, they should be able to give you a starting point for your quad and elevation. Otherwise, I have a gold series pipe on my '85 with a UNI and no lid. My bike runs pretty well, I can give you my settings but the '85 has a 1mm smaller carb and I don't know what size my piston is(it just now needs the first top end job since I have owned it.)