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Honda4life05
03-28-2008, 09:42 PM
what jet size should i use on my 300ex?. I have a fmf q2 full system,K&N filter,air-box lid removed,and an outerwears cover on the filter.

thanks, aaron
JohnT_98300EX
03-29-2008, 02:08 PM
I have a similar set up. 300EX, FMF Q2, and 6 Uni filter vents in the air box lid. Info from the FMF web site says a 128 or 130 main jet and no other carb changes from stock. I went with a 128 main jet.
The change in throttle response will make you smile. Mine starts, runs, and idles like a stock set up. But the difference in the way it pulls 3rd and 4th gear is worth removing and putting back all the plastic and the tank.
Honda4life05
03-29-2008, 03:22 PM
ok thanks for the help, the 28 is the biggest jet my dynojet kit came with so ill put that in. Do you think i can run it with the air-box lid on with that set-up or does it have to be off? its a little louder with it off.

thanks
JohnT_98300EX
03-29-2008, 04:41 PM
Personally I won't run without a lid. I'm to lazy to clean a filter that often and engines hate internal sand.
The instructions from the web site were vague at best. They just recomended "air box relief". I went with 6 Uni filters. I have not bothered to do a real plug read with fresh plug yet. So I have no idea how close I am to "perfect" jetting. The plug that's been in it all along looks decent to just pop it out and look.I do know that it starts and runs well and smooth. There is no exhaust fog from being rich and the pipe is not getting to hot. When it was to lean it would turn some intense blues and gold.
bwamos
03-29-2008, 11:13 PM
A 128 dynojet jet should be about perfect with the airbox lid off.

dynojet jets and standard keihin jets don't really compare. A keihin jet you'd be about a 132.

Keihins are numberd by flow rating. Dynojets numbers are orifice diamater.
JohnT_98300EX
03-30-2008, 04:37 AM
And mine is a keihen jet. (to early to spell). I just learned something new. I had no idea size varied by brand.
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Honda4life05
03-30-2008, 12:26 PM
if i left the air-box lid on an drilled like an inch hole in it would it be ok? would it be as loud? or what is the best size if its ok to drill a hole?

thanks