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Speedy 400ex
06-07-2008, 11:17 AM
Im putting a home made EHS air box lid on my ex and it has been jeted for the stuff i have in my sig but not for the lid. it curently has a 40 pilot and a 155 main. i noticed that the main is some what adjustable should i adjust it or move up a jet size? by the way i ride from sea lvl to 2000ft.

Also what size are the bolts the hold the carb float chamber? My mine where so stiped i had to make them flat heads to get them off.
drew416ex
06-07-2008, 03:18 PM
Leave that where it is. That mainly adjusts 1/4-3/4 throttle (needle circuit). I messed with mine once and thought I would never get it back how it should be.
Speedy 400ex
06-07-2008, 03:27 PM
ok what do i need to change then?
drew416ex
06-07-2008, 03:42 PM
I would get a new spark plug and run it and see how it is on that main jet. Even if its lean it wont be lean enough to hurt the engine. You shouldnt have to go up more than one or two sizes if any.
GPracer2500
06-09-2008, 06:10 PM
The part the main jet screws into is not an adjustment point. It should be bottomed out into the carb body (not too hard--we're talking brass screwed into cast aluminum here) and then the jam nut locks it in place.
drew416ex
06-09-2008, 07:52 PM
Originally posted by GPracer2500
The part the main jet screws into is not an adjustment point. It should be bottomed out into the carb body (not too hard--we're talking brass screwed into cast aluminum here) and then the jam nut locks it in place.

Mine wasnt bottomed out from the factory. I can remember exactly but it had about 1/16" of threads showing.