When I bought the bike the main bearings were out so I gave it a rebuild, chunks of main bearings destroyed most everything in the engine. Anyways I bought a rod kit and it turns out there is a misprint in parts unlimited catalog and they sent me a 220 rod, since I already had it and had all winter to work on my engine I compared it to my other rod and the only difference is that it is about a 1/8 in.(forgot the exact measurement) longer than a 200 rod, so right a way I thought more compression, so I used it. I had to fab 2 16 gauge spacer for the bottom of the cylinder, I made three but ended up using only 2 spacers and 2 gaskets to get the compression I wanted. The bike runs good just seemed like a little slugish off the start and I think I might know why when I was just changing these jet I found that it had a 30 pilot jet, stock is 25, this seems like a big jump for a pilot jet maybe getting to much fuel at low rpms. However the 330 main jet I put in, I could definitely feel more power. I'm going to switch that pilot jet and see what happens when I go back to the parts store I'll buy a 310 and a 340 give em both a try, it's kinda weird someone would change the pilot jet 5 over and not the main in a what was before a stock bike.