Maul Posted June 12, 2009 Report Posted June 12, 2009 just rebuilt the top end fresh .30 over bore and new wiesco's but i'm only getting 85 lbs of compression and the bike has no bottom end. Why would my comp be so low thanks Quote
#1JUANstunna Posted June 12, 2009 Report Posted June 12, 2009 Not trying to be a smart ass but did you put on the rings? Are you checking it at WOT? Did someone that knows how to bore a two stroke with tight tolerances bore it? Maybe it was overbored. Quote
Maul Posted June 12, 2009 Author Report Posted June 12, 2009 Not trying to be a smart ass but did you put on the rings? Are you checking it at WOT? Did someone that knows how to bore a two stroke with tight tolerances bore it? Maybe it was overbored. Yeh I put in the rings but I bet there has been someone out there that hasn't. Yes checking it at wide open had a napa machine shop here in town bore it. I guess its possible that they could of over bored it. I did give them the new pistons when they bored it so the could match it up. How much clearance should the pistons have. i did check the rings and they were ok. Quote
AKheathen Posted June 12, 2009 Report Posted June 12, 2009 were the ports rechamfered? which direction did you install the ring bevel? Quote
Maul Posted June 12, 2009 Author Report Posted June 12, 2009 were the ports rechamfered? which direction did you install the ring bevel? No on the ports and i installed the rings with the markings up which i think makes the bevels face down Quote
AKheathen Posted June 12, 2009 Report Posted June 12, 2009 No on the ports and i installed the rings with the markings up which i think makes the bevels face down the ports need to have a chamfer to them, or they will chew up the rings Quote
black sunshine Posted June 12, 2009 Report Posted June 12, 2009 Did you cross-check with another gauge? Your tester could be garbage. Banshee's have no bottom end. Quote
AKheathen Posted June 12, 2009 Report Posted June 12, 2009 Did you cross-check with another gauge? Your tester could be garbage. Banshee's have no bottom end. i beg to differ. mabey not that of a 4 stroke, but i'ts there Quote
Maul Posted June 12, 2009 Author Report Posted June 12, 2009 the ports need to have a chamfer to them, or they will chew up the rings I bet you hit the nail on the head with having the ports chamfer. Bet they justed bored it since there more of a automotive machine shop. When I first had it done I thought maybe the rings didnt seat so I threw a new set in there but had the same comp. Can I get the ports chamferd without re boreing and is this something that I should send off to get done. Thanks for the help guys. Quote
jbooker82 Posted June 12, 2009 Report Posted June 12, 2009 I bet you hit the nail on the head with having the ports chamfer. Bet they justed bored it since there more of a automotive machine shop. When I first had it done I thought maybe the rings didnt seat so I threw a new set in there but had the same comp. Can I get the ports chamferd without re boreing and is this something that I should send off to get done. Thanks for the help guys. You could do it yourself but I would send the cylinders and pistons to a builder to look over napa's work. Quote
Maul Posted June 13, 2009 Author Report Posted June 13, 2009 (edited) You could do it yourself but I would send the cylinders and pistons to a builder to look over napa's work. How would you recommend on the west coast Edited June 13, 2009 by Maul Quote
#1JUANstunna Posted June 13, 2009 Report Posted June 13, 2009 Send them to Kevin at Herr Jugs Racing, he's a site sponsor. I think he's in CA. Or send them to Jeff @ FAST, he's a site sponsor too. I deal with him great guy and costomer service is great too. Quote
gregrob Posted June 13, 2009 Report Posted June 13, 2009 .002" is the clearance. .003" actually. But whos counting Quote
Maul Posted June 13, 2009 Author Report Posted June 13, 2009 pulled the jugs last night and there is only scaring on the front and rear of the cylinder the sides look like the rings never even touched them. also the pistons look brand new. i would hate to have to get them re bored and buy new pistons but it looks like that is what i'm going to have to do Quote
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