Jetting for TT500

Can anyone give me jetting specs for a 34mm VM round slide Mikuni for a 1980 TT500? I'm replacing the stock dual throttle cable carb with this one. I know everyone uses the 36 or 38 as the replacement but I'm not looking for more power just simplicity. Also, need a throttle cable to fit a Gunner Gasser and the 34mm Mikuni. Thanks

:cry: Thumpnut,

Try a posting on Lots of vintage TT/XT/SRs there. Got lots of info a few years back when I built and HL500 Replica. I'd use a 36 or 38. Mine ran best with a VM38. Jetting for a 34 should be basically the same. Pilot jet, needle jet, slide cutaway, etc. should be about the same. Main jet will be a little smaller. My notes went with the HL so I can't give you specs.

If that's an old two smoke carb, be prepared to throw away/replace just about every metering circuit inside$$$. They use different needles, needle jets, slide cutaways,air jet, etc. Pilot, main jet are the same style just different numbers. It's usually cheaper, unless you've got a big pile of VM mikuni parts, to find a VM36/38 that came off a TT on ebay or buy a prejetted VM. Try or (vintage flat track)

Don't know about the cable for a gasser. Good Luck!!! :cry:

If you are after a reliable turnkey setup then the stock goods are great. Very easy to work on too.

If you are looking for a simple setup that provides good performance then use a 36mm roundslide. The 34 is rather small and I don't think anyone has gone through the hassle of jetting such a small carb. For a 36 or 38 or even a 40 it would be easy to come up with some jetting specs. It would help to know the build of the engine... Airbox? Exhaust? Etc...


It would help to know what altitude you are jetting for. I'm at 5000 feet and run a 2.5 slide, 180 main 30 pilot and a 159 series nozzle. There are different combinations of nozzles and needles that can be made to work with one another...I recommend a Mikuni tuning manual. Check Ebay for one. They are invaluable and you will learn what changes affect the carb's performance.


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