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Jetting with an HMF
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Posted by: Green95Hoe

First off, im gonna apologize up front for what may seem to be yet another posted question without searching. All I found was jetting for the 450. Hopefully I can find someone who has my setup and save myself alot of time.

I bought my 400 used with a stock pipe but I have reason to believe it was jetted before I bought it and the shop put the stock pipe back on. Today, im running an HMF Bill Ballance Slip on, factory headers, K&N and outerwear built into the lid. Im also considering scrapping the choke since Ive never once come close to needing it. Looking to know a comfortable main jet size. Ive been guessing 160 based on what ive heard but I need second opinions. I dont even know whats factory. Thanx in advance fellas

~Brad

Posted by: hawaiiansupaman

im running 160 MJ with the stuff in my sig. also lid off a little rich but it works

Posted by: jak1389

stock main jet is 148. i am running a 160 main 40 pilot needle on the 3rd clip, and no clue about the fuel screw, i just adjusted it until it was perfect. just start off at 155 at if its too rich go down a size too lean go up. just start from somewhere you think is close.

Posted by: 400exstud

I am running a 160. May be a bit rich but better safe than sorry. (I don't foul plugs much so......

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Posted by: Green95Hoe

Wow, thanks guys. That answers my question.

~Brad

Posted by: 04'400ex'er

quote:
Originally posted by hawaiiansupaman
im running 160 MJ with the stuff in my sig. also lid off a little rich but it works

Dynojet are bigger than stock jets. 160 main should be a close start though. maybe a 42 pilot.