440EX jetting

[patrick delao]

I need some help on my bike's jetting. I'm installing my 440 kit this weekend and need some info on where to start at with my jetting. I have a 440 kit 11 to 1 piston I have the XR head gasket and cam I had the base of the jug milled about .030 so I'm about 11.5 to 12 to1. stock carb, FmF P/C4 with power bomb header, K&N filter with no lid. I'm at 5600 feet and I have a 160 main & a 40 plt. needle one clip down. I was thinking of going to a 175 main what do you think ? any help please

[oynot400]

I can't remeber what mine was at when I had the stock carb, may be a 170 main and 42 pilot. I am not for sure. Check with FMF they have a pretty good jet guide, that is what I did when I did my 440. ;)

[patrick delao]

Did that 39mm carb make a differance on a 440?? Was It hard to get use to a a twist on whoops? I just put mine on and only have like 2 hours on it , little hard to get use to.

[oynot400]

Yes it did make a difference, huge difference!:D I noticed power gains all through the power band. I was lacking a little on the bottem end and it sure helped it out. I can pull a 3rd gear wheelie now.
As far as the twist I didn't like it, it felt too loose or something. It didn't feel right to me, so I went back to the thumb. I am sure I could of gotten use to it, but for the $12 for a new cable I have a choice now.

[400exJOE]

can i expect these kinda gains from a Lectron 38mm with a 440? Anyone have this set up?

[Chef]

i dont know if this helps or not, but i have a 195 main and a 60 pilot in 45 degree weather in washington, and its just a tad bit lean i think

[oynot400]

Originally posted by 400exJOE
can i expect these kinda gains from a Lectron 38mm with a 440? Anyone have this set up?
You should see some power gains with any larger carb, mainly because it is letting the engine breath easier. :)