First check your squish, You'll need some soldering lead. Pull your plugs, take a peice of the solder about 8in long bend it to where you can get it to touch the cylinder wall @ 3 and 9 Oclock paralell with your piston pin. Turn the motor over slowly by hand.
This will squish the lead. Measure the lead thickness with a micrometer. Your goal is .060. If its over thats what you have cut. Alot of guys just cut .010 off. Most machine shops can do this for you for about $120
It does clean the sled up pretty good, But you may have other issues causing the bog.