Anybody out there still running with lid on with fmf exhaust and k&n filter? Mine seems to run so lean that if I put the lid on it runs much better.
air box lid
- Thread starter jaddict
- Start date
That's because you need to reject for the increased airflow allowed by the pipe. Increased air = need for increased fuel. Without rejetting....you're gonna melt your piston AND it defeats the point of having the FMF. If you're not gonna rejet, then at least put the stock pipe back on before......KABOOOOM!
After running it lean like that, I would do a compression check to make sure the top end didn't take any damage. I don't know how long you ran it like that.
It ran lean with a 310 in it, I Put the lid back on and it ran great good ,good plug chop. I couldn't get a good plug chop until a put a 340 in it with lid off. So I put the lid back on. Was just wondering if anybody has the lid on still with the same mods I have. It seems that a lot of people don't use the lid. Compression is at 150 , no leaks
Wow, 340 is BIG, it almost makes me wonder if you don't have a vacuum (air)leak somewhere. I really can't imagine that it would be that lean otherwise. 310 is Toomey territory & I don't think the FMF is the same beast. Start checking elsewhere man.
Could the carb be letting in some air when it is bolted up, is the little nipple on the oil intake on the carb.
#340 main is really big for a FMF without the airbox lid on.
What oil/fuel ratio do you mix to?
#340 main is really big for a FMF without the airbox lid on.
What oil/fuel ratio do you mix to?
340 was with lid off. I have 310 with lid on,Nipple is on carb,checked for leaks with carb cleaner. 32:1
What jet were you running in summer? I was running 310 in summer with lots more done to it with no lid. Tho spraying around outside is a good quick check, it cannot detect seal or case leak. Do a proper leakdown test, use soapy water and find leak. Thought someone else would have also responded.
hey i can back jaddict up on this one... u all can search my thread cuz im not going to go into explaining it again, but i had done numerous checks for leaks such as leak test, compression, sprayed carb cleaner around carb when running to see if there were leaks there, and no.... but none of my plug chops are as dark as the tutorials on here... and i did about 10 chops... all held wot for 30 sec at least... but i must say in my situation, the blaster runs great, although i havent tried putting the lid on to see what happens... its just the chops dont agree...
