I have broken a couple of 686 sleeves.............I read something about someones sleeve cracking with a 102 bore, and they were going to put a 700 sleeve in it. Is that hard to do or is sleeve cracking at 102mm not common?
Stock 660 cylinder bored to accept the 700 sleeve, same for the base, it is bored bigger, the 700 sleeve is twice as thick at the bottom and also stronger at the top.............willy killer how did you make the 700 sleeve fit in the 660 base and did your sleeves crack on your race quad? I don't race (wish I could afford it) Just ride trails so I'm not WOT all the time would this still be something I need to worry about?
Right on, basically jetting changes has more to do with the air box mods then the exhaust, I have run no air box for years and the jetting is pretty well the same even if I change cams or exhaust...........Now that you've stated your mods: 160L/165R Mikunis, 25 pilots, aftermarket needles with clips at or just below middle notch would be a good starting point - you're mileage may vary.