kaptainbutler

2007 Honda 400EX Aftermarket Combination?

6 posts in this topic

I have a FMF Powerbomb Header, FMF Powercore 4 Exhaust, K&N Filter and a Dyno Jet kit. Powerecore has a decent dent in the side from a wreck, but I dont think it is affecting the inner flow, the cylinder inside seems to be just fine. However, Im getting spanked everywhere except a little on the low end. I even had a factory get me the other day on a straight away race. The only thing he had done was remove the baffling. I thought I had a pretty good combination, what am I dont wrong. i am at a wall and can not get it tuned in. Thanks ahead for any suggestions.

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Three things could be a factor here. One, riding style, if someone is getting a better launch and is shifting at a more optimal RPM, he can win in a race against a more powerful machine. Two, rider weight, a heavier rider means more weight that the motor has to move, I think that one explains itself. Third, your machine may not be tuned correctly, you may need to make some tuning adjustments like jetting, vavles, are you running an old plug?

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also, if youve flipped the bike recently you might need some carb cleaning! i would suggest you get rid of the fmf package, there are many underdogs making great performance pipes like SUPERTRAPP. might also look into repacking that fmf?

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Thanks guys, i didnt flip I was spun and the guy rode up onto my rear tire hitting my exhaust. Either way i did recently completely clean the carb. Im running the suggested Dyno jet for an aftermarket pipe, would I be wasting time to go up one more and see if it helps? Thanks again

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No, you would not be wasting your time, jetting off a chart is not the best way to go about it. Besides, you need to take the intake changes into consideration too. A pilot jet change may be in order, or maybe just an adjustment to the pilot screw. Learn to read your plug, it is your best indicator for jetting besides engine performance. I could sit here all day and try to explain to you how to properly jet your machine, but I think you would do better to just use your search engine to do some research. Look up "plug chop" and just try to find as much info on jetting as possible and read up on it.

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put a lrd full exhaust on after market cdi box and change your gearing.... then kick every bodys but on the trails and track

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