My 2007 Beta Rev 3 250 has always felt just not right at the bottom end.

Couple of blokes yesterday mentioned it just dosen't sound 100% - thing sounds

like it's fighting itself.

Plug is slightly sooty but never had a problem with it oiling up.

Generally the bike runs ok.

Running the mix at 75cc of 2 stroke per 5 litres of fuel.

I removed the carb yesterday, its running a 150 main, 30 pilot and the air screw

was sitting at 3/4 of a turn out.

Any advice on the carb settings before I start tweeking.

Cheers

Ive always had my air screw one and half turns out on all my betas, you may have to adjust slightly from time to time.

Mikuni VM26-208 drop the pilot to a 27.5. You may drop the main one or two sizes as well. I think my 05 has a 140 or 145 main but I don't remember. The 27.5 pilot is pretty much the first thing anybody did around here with the Mikuni. VForce carbon reeds also make a big difference in the way the bike runs low. Adds tremendous grunt.

Agree with Dan's jet sizes

I have the same bike. Mine has 27,5 pilot and 145 main and it runs lean. I wasn't happy.. Now I put 30 pilot and 140 main and it runs much better )

I ride most of the time around 5oom altitudes.

All the Betas are on the high compression side so race gas is kind of a necessity. Jetting rich can help to some extent but you end up with a boggy engine. I suppose you could go with a thicker base gasket to lower the compression if you want to run pump gas.

Fitted a 27.5 Pilot and a 145 Main Jet for a midweek trail.

Air screw out 1 3/4 turns.

If anything - I reckon its very slightly - might need to tweek the needle.

But overall - the differance is just superb.

Even on tick over - the bike sounds different.

Think its not far away now.

Ah now add a VForce carbon reed valve to the beastie and you're done.

Clean the exhaust. It will need it by now. See how it goes after.

Cheers,

Stork.