BANJO Posted October 17, 2006 Report Posted October 17, 2006 i had my piston skirt blow apart.. intake side.. i bought this engine and its a 98 bored .50.. it started up fine but it had a knock inside the engine.. it ran fine.. idled fine.. my plogs were a dark brown all the way around and down after a 2hr run.. so im perty sure it was rich.. i have the 2into1 trinity.. (personaly dont think it works true..) anyways i was ridin and pop.. at first i thoght it was a rod bearing... i rode this engine even know it knocked cuz why fix it till its broken... and i got about 5hrs out of it.. but im wondering why the piston skirt broke into peices??? jetting?? slaping??? what ever the knock was??? also the engine is sapost to be ported??? but the ports are still black inside.. its a rough black paint.. isnt it sapost to be raw metal if ported?? unless the porter sparyed it?? the holes look bigger but im not sure since its still black.. a clean up port is what its sapost to have.. questions... - why piston skirt blew apart?? and its not ported is it... sorry no pics... thanks devin.. when i removed the crank.. the bearings were ..well dead... they wobbled perty bad.. so im thinking the crank was shaking.. causing the piston to slap.. and making the knock??? what you think?? Quote
gumby6t9 Posted October 18, 2006 Report Posted October 18, 2006 The "knock" could be from both the bad crank bearings and a worn cylinder bore. I would measure the bore to see if it needs to got to the next oversize since you have the motor apart. Quote
BANJO Posted October 18, 2006 Author Report Posted October 18, 2006 clinders were tight.. lots of compression... but i got bigger pistons anyways.. still dont know about my port work... do some porters spray paint back over their work?? devin Quote
gumby6t9 Posted October 18, 2006 Report Posted October 18, 2006 I doubt that if it was ported that it would be painted black inside the ports. I would still measure the bore to make sure it isn't worn but like you said the bearings could be your major culprit. Quote
Ducman Posted October 18, 2006 Report Posted October 18, 2006 If it has a rough "cast" look to the entire port then it is not ported. It could be painted but that would be very unusual. I would take it to a mechanic to check the rod end play to see if it is in spec and you should flush the case to make sure all the bits of metal are out. Sounds like the piston was slapping, probably incorrect cylinder tollerances. Hopefully getting it bored correctly might fix the problem, but you need to have the crank checked out too. Quote
BANJO Posted October 18, 2006 Author Report Posted October 18, 2006 .... lol... yeah i figuerd it wasnt ported.. and i have the engine in peices.... i got all new parts/internals from jeff at f.a.s.t.. great guy... thanks devin Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.