My son was getting about 7.5 minutes with the .28 last weekend at 150 cc's but it is still tight enough that you cannot turn it over by hand, it stops before TDC. We are hoping to get it to the 8-9 minute mark when fully broken in.

The engine is a beast, really strong throughout, top to bottom.

Anyone try the Sportwerks 053 pipe, Jp3 or RB 2045 on it ?