thecableguy006 Posted April 30, 2008 Report Posted April 30, 2008 i just rebilt my motor had it all ported polished did coolhead bigger pistons and everything. it ran good during the brake in took it to the dunes for the weekend and came back did a compression test it had 150lbs in the left and 30lbs in the right tore the motor down pistons were black and one was missing half of the clip an there was chunks outta the top of the piston and the cylinder is damaged. i did gear saver oil in the motor and mix castor 927 in the gas with a 40:1 ratio. what happened? what should i do different next time? Quote
jbooker82 Posted April 30, 2008 Report Posted April 30, 2008 Did you check piston to cylinder clearance? Ring End gap clearance? Maybe the guy you had bore your cylinders didnt chamfer the ports so a ring caught a port. Quote
thecableguy006 Posted April 30, 2008 Author Report Posted April 30, 2008 Did you check piston to cylinder clearance?Ring End gap clearance? Maybe the guy you had bore your cylinders didnt chamfer the ports so a ring caught a port. the guy that did it took about 4 weeks to finish it i had them ported polished and blueprinted he said that they should be perfect but i did not double check. im going back to him tomorrow to see what he can do Quote
jbooker82 Posted April 30, 2008 Report Posted April 30, 2008 I am no expert on decoding engine explosions but it looks like a ring problem. End gap to tight and it bound up, or just plain broke. Quote
thecableguy006 Posted April 30, 2008 Author Report Posted April 30, 2008 I am no expert on decoding engine explosions but it looks like a ring problem. End gap to tight and it bound up, or just plain broke. im starting to think your right on the porting that the ring hit because there is a chunk out of one of the ports and the back of the ring is missing Quote
dajogejr Posted April 30, 2008 Report Posted April 30, 2008 WTF does blueprinting mean??? I know what it means on a car, but that is the first time I've ever heard it used on a bike...LOL... Let's see more pics. Does it have scarring in all 4 corners of the piston (four scrapes?) It could be cold seize...did you let it warm up a while before blasting off on it? Either cold seize or a ring got caught....either way, I'd be finding a new guy to help out on your bike.... Quote
kawiking Posted April 30, 2008 Report Posted April 30, 2008 i cold seized my shit about 3 months ago.. had 5 hrs on it as well. snapped the damn skirt off the piston. had jeff check the cylns... he said that one was alittle to big on the bore.. i feel for u man.. i had the same shit go down. makes u sick. Quote
KaosBanshee44 Posted April 30, 2008 Report Posted April 30, 2008 Looks like a ring got caught with the exhaust burns down the lower side of the piston....I don't think cold seizing it would cause the rings to just rip the fuck off. Quote
dajogejr Posted April 30, 2008 Report Posted April 30, 2008 I agree totally. But it could have multiple problems....that being one of them. It could've cold seized before, left a mark on the piston, ring or skirt...then catching a port smoked it totally... If it has 4 corner scarring, it could be an additional problem... Quote
KaosBanshee44 Posted April 30, 2008 Report Posted April 30, 2008 Dave i think i know what your talking about, hopefully he will show some more pics. Either that or they just put one ring in and left the other one out...lol Who the fuck knows Quote
shanYE west Posted April 30, 2008 Report Posted April 30, 2008 Looks to me like the ports wern't chamferd.. that big snag was right over a transfer port.. Quote
F.BEJARANO Posted April 30, 2008 Report Posted April 30, 2008 Dont want to hijack the thread but what is ring eng gap clearence. Quote
DEADONE Posted April 30, 2008 Report Posted April 30, 2008 Looks to me like the ports wern't chamferd.. that big snag was right over a transfer port.. hey not to sound like a dumb a$$ but did you check you bottom end? i kept have about the same problem and found a rod bearing and one crank bearing shot Quote
jbooker82 Posted April 30, 2008 Report Posted April 30, 2008 Dont want to hijack the thread but what is ring eng gap clearence. You put the ring in the cylinder and use a piston head to make sure it is square in the bore. Then you use a feeler gauge to measuer the ring end gap. Quote
thecableguy006 Posted April 30, 2008 Author Report Posted April 30, 2008 You put the ring in the cylinder and use a piston head to make sure it is square in the bore. Then you use a feeler gauge to measuer the ring end gap. i didnt check the ring end gap or the bottom end i am taking the cylinders back to the guy that did the machine work because there is a big chunk out of one of the transfer ports. Quote
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