Starting main jet suggestions

[cabowabosam]

Motor has a fresh build on it, and I am getting prepared to put it back in the quad for some heat cycles but wanted some advice on what main jet to start with. 207cc, no port work, FMF Gold series, FMF power core 2, K&N filter, no air box lid, oil injection has been removed, Mikuni VM 30 (30mm) carb, new stock reeds, 892 feet elevation level. Current main jet is a 250, thinking I need to be 280-290 range to start with. What do you guys suggest? I will be doing plug chops but wanted a starting point. It has been a long 4 year wait to get this back together...

 

[Blaaster]

Start with a 300-310 main, and then after full break in plug chop to confirm.

If the main jet proves to be too big it will not affect the heat cycles or any throttle opening below 3/4 open.

 

[jus_me]

Was this carb run on this bike before the rebuild and all ok ? I only ask to be sure your pilot is ok and not extremely lean since it is a 30mm carb and not knowing what make model it was designed for.

 

[cabowabosam]

Yes it was on it before but with a smaller bore and stock head pipe.