The sled is a screamer, and I have had nothing but good luck with the machine. (until recently, read my posts titled "the race" and "the aftermath") Sled always starts on 2-3 pulls and runs great. The only mods so far are 144 studs. I've found that it won't beat a formula III 600, this is really depressing. I thought the trade off for the added weight (75-100 pounds heavier) would be more horsepower. I was totally "frazelled" to discover that the formula III has the same top end. I'm going to look into gearing it for more low end (who needs top end anyway, I don't ride in Canada and it's not a lake racer) or maybe just giving it to my girlfriend and finding a sled that "won't take no crap" from a 600cc.