By Brian Young on Unrecorded Date: Edit

I have a JLO Rockwell twin cylinder snowmobile engine in my MaxII with a tillotson carb.the carb has a adjustment screw on the side and one on top.it started running kinda rough so i thought i would mess with the adjustments not realizing that when i lowered the body down last time i was pinching a fuel line.now i cant get the carb tuned right for the life of me..any sugestions besides having a REAL mechanic look at it?

Brian

By david berger (Davidrrrd) on Unrecorded Date: Edit

are you shur it's a tilotson?
i have only sean the ones with 2 screws on the sides, with them start with 1 1/4 turns out on both and then adjust, i did one once by driveing my attex across a large airport sized parking lot on a sunday all by myself with the throtle wide open while i fiddled with high screw and low screw, each time adgusting back in forth and centering best points and trying again to see how it acilerated, ect..ect..
with a max you can remove the tires and chain to a tree with hubs on sheets of plywood maybe to simulate a load, you need to be under a load when you adjust carb if you realy want it to run like when you adgusted it, this way you can tweek it while runing like your rideing, it's not the safest thing revin without being under a load anyway, and wach your eyes for backfires and flying oil from chains ect.. id ware some safty gogels ,the uper body might mouse trap you too with all the extra vibration, be shure to tie some rope threw cooling openings around prop loop and do this on flat serfice so loop dosent bend to one side or something, better yet be shure someone helps you when your heads inside the body and your reving the shit out of the drive train while doing yer adgustments,

By Kevin Percy on Unrecorded Date: Edit

Take a look at the picture on the following link.
http://www.mercurysnowmobiles.com/hrcarb.htm
I think in the hard to read print is says how to adjust the needles, I'd only add that after adjusting the high speed needle to obtain maximum RPM, open it 1/8 of a turn so you leave it a little rich. Gas is cheaper than pistons !
You may only have one mixture needle, the high speed may have a fixed jet with a plug over it.