murray jetting

I have my wonderful Murray, running a 68 jet right now. I have a Proma gp pipe, i did the pantyhose airfilter thing, and I have a 12 tooth front sprocket. how much should I upjet?

I'm not too sure what size carb i have. I'm pretty sure its a bing, because there was a small be on one of the parts of the carb.

The upgrades I made hardly affected the performance, so I'm hoping some carb cleaning and upjetting'll help. Any suggestions for someone with maybe a similar setup??

Re: murray jetting

plug chop.

Re: murray jetting

You should have a Bing unless someone changed it around. Check the Bing wiki article for pictures and info. If you look closely at it (you might have to take it off), you'll see three numbers on it -- 1/12/213 or 1/14/536 or whatever. The middle number is the size. 12 = 12mm, 14 = 14mm, etc. If you didn't upjet after you added the pipe and changed the air filter, you will probably need to. The sprocket size shouldn't really have any effect on how you're jetted, although it certainly will affect your speed. Check for air leaks and run a plug chop and see what that tells you.

Re: murray jetting

When I added a Tecno Boss pipe to my Murray with stock 12mm Bing and airbox, I only upjetted from 68 to 70. Anything higher (72, 74 and 76) just kept flooding the motor. Is that normal? I didn't perform a plug chop, just worked my way down from four sizes up.

Re: murray jetting

I think the air leaks might be a prob. I'll check that out. I got my carb all taken apart, so I'll slap that back on and then plug chop when it gets warmer. Thanks for the advice linda and other people. Hoping I'll gain a little speed for my investments

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