I have a 670 bored and stroked to 800cc with P85 primary and arctic cat hymark secondary, crank shop 50mm carbs, SLP twin pipes and stock can. The first question I have is what rpm should I be running with these pipes? It is running 7,900 right now and I cant seem to get it any higher, I have tried lighter weight, lower/higher mains, different springs and it does not change. The engine pulls hard right off the bottom but seems pretty flat on the top end, if that makes sense? Any advice on what I should change to get this engine to run better? All of this is at 3,000-6,000ft. Currently my main jets are 580, 600 @ 3000ft. Any help would be greatly appreciated.
