No, it already had 310s in it, figured that was big enough. No, I have not done a leakdown test, I don't have the tools for that...never even heard of it on a 2 stroke until I saw in on this site lol. I put new crank seals in and oiled them first (have seen seals burn up in auto applications when put in dry) when I changed the crank. It had the same problem before I downed the engine, but ran fine with the stock pipes.
The problem is that when you run it though the gears, when you hit 6th it starts sputtering like it is fouling a plug. I also like to ride wheelies, and when you are on the back tires and click it in 4th it sputters also. I lowered the floats yesterday and it helped the 6th sputter, but the wheelie sputter is still the same...one more thing, I usually just blip the throttle and shift without using the clutch, if you never lift and just clutch and shift, the 6th sputter is almost non existent.
B8ES NGK plugs.