Need help with Main Jet starting point!

[TRX23rider]

ok guys, i got my carb apart and i have a problem! i am at a 170 MJ right now, and i dont have any bigger jets. i had a K@n powerlid and filter, and i put on a HMF pipe and FMF header. where should i start with the MJ? i live in upstate NY, and it is like 30* out right now. do i need to go as big as 180? with someone with this similiart setup please help me out? thanks alot!!:)

[400exstud]

A 170K should be quite a bit too rich. I would say closer to a 160K.

[TRX23rider]

when i took my quad to the honda dealer to get it jetted they put in a 170 mj and it ran fine. then i got a pipe and header and it needs to be rejetted, so your telling me i need to go lower on my main jet?????

[400exstud]

Yeah, a 170 is pretty big.

Pappy and Mobiledyno are very good with jetting. They may be able to steer you in the right direction.

[tprender]

If you still have a stock engine, the main jet should not be any larger than a 165. Most likey it will need to be around 160. Are you talking stock jets, not the dyno jet kits??

[440exnacsracer]

the highest i ever ran in my 440ex was a 180, but if it was running fine with the 170 before the header, try a 175, considering the cold conditions, it may be acceptable. i would not go to a lower jet if it is not stumbling or hesitating right now though. it is better to be a little rich than lean.
Ben

[the Z Man]

I have a hotcam stage 1 open airbox and a GT Thunder full system, I run a 200 main and a 52 pilot, this thing rocks!!!! and she fires right up everytime!!
I would try a 190 and go from there,

[400exstud]

I have a hotcam stage 1 open airbox and a GT Thunder full system, I run a 200 main and a 52 pilot, this thing rocks!!!! and she fires right up everytime!!

When I tried a 180K my bike wouldn't even go in 3rd gear!

[the Z Man]

My bad, I was thinking 450r, I run a 160 in the ol 4 hundy, open airbox hotcam stage 2, HMF pipe..oh, some port work too..