252wheelieking Posted March 2, 2012 Report Share Posted March 2, 2012 (edited) Bad news again BHQ fam, I blew my motor again today. I dont know what could have cause this to happen. I had fresh bored/hone by HJR with brand new wiseco prolite pistons (64.75). wiseco gasket kit, chariot coolhead w/ 21cc domes, & new oring kit from JL, +4 timing. I put everything together by specs. from Cylmers manual. I did leakdown test & it pass. I ran 32:1 castor 927/ pump 93. Today I went to start it & the kicker was light as in low compression. So it kicked it three times & it started on the third kick which was normal. It wouldn't idle so im thinking it won't idle because the weather was in the high 70's today & it was jetted for 40-60 degrees. I lightly held the throttle until it warmed up & took it down the road when it shutdown. I pull in the yard & it started back up but only fired on one cylinder. I tore the topend down to find this: What didn't i do right? Edited March 2, 2012 by 252wheelieking Quote Link to comment Share on other sites More sharing options...
sprinklerman Posted March 2, 2012 Report Share Posted March 2, 2012 Are those needle bearing marks in the domes and on the piston tops? its odd that theres damage on both sides if those marks are from the wrist-pin bearings.. Quote Link to comment Share on other sites More sharing options...
Coupelx Posted March 2, 2012 Report Share Posted March 2, 2012 that looks like mechanical damage. as in something has gone through the engine. Quote Link to comment Share on other sites More sharing options...
dcalsv02 Posted March 2, 2012 Report Share Posted March 2, 2012 Check your crank. Is your crank welded? Could have lost the needle bearings from the connecting rod. Quote Link to comment Share on other sites More sharing options...
camatv Posted March 2, 2012 Report Share Posted March 2, 2012 this happens crank let go. on older motors freshen up the top end and a lot of times the let go after that. Quote Link to comment Share on other sites More sharing options...
sheerider1026 Posted March 2, 2012 Report Share Posted March 2, 2012 Id check water impeller. Or cooling system.. Quote Link to comment Share on other sites More sharing options...
Coupelx Posted March 2, 2012 Report Share Posted March 2, 2012 this happens crank let go. on older motors freshen up the top end and a lot of times the let go after that. http://img.photobucket.com/albums/v114/Fraggster/DSC00388.jpg Quote Link to comment Share on other sites More sharing options...
Infamous039 Posted March 2, 2012 Report Share Posted March 2, 2012 this has happen to me in the past as well and it was my crank bearings that went. Your might as well go 4mill now since you will be changing out the crank. Quote Link to comment Share on other sites More sharing options...
Phelps Posted March 2, 2012 Report Share Posted March 2, 2012 i have a piston just like that from a water pump failing. Quote Link to comment Share on other sites More sharing options...
sheerider1026 Posted March 2, 2012 Report Share Posted March 2, 2012 i have a piston just like that from a water pump failing. i agree with the jew Quote Link to comment Share on other sites More sharing options...
252wheelieking Posted March 2, 2012 Author Report Share Posted March 2, 2012 Are those needle bearing marks in the domes and on the piston tops? its odd that theres damage on both sides if those marks are from the wrist-pin bearings.. I have not removed the cylinders yet so I dont know. It puzzles me also that both pistons are damaged. I am going to pull the cylinders today & they are going to be in the for sale section. Im tired of rebuilding this damn stock stroke. Quote Link to comment Share on other sites More sharing options...
252wheelieking Posted March 2, 2012 Author Report Share Posted March 2, 2012 Check your crank. Is your crank welded? Could have lost the needle bearings from the connecting rod. I hope it isnt the crank, I just brought this crank from a site sponsor & was told that it was a very low hour crank that was used for one season. It was true & welded, installed new outer bearings & fully inspected by the site sponsor. He said it came from his personal bike, so I believe him. Quote Link to comment Share on other sites More sharing options...
252wheelieking Posted March 2, 2012 Author Report Share Posted March 2, 2012 this happens crank let go. on older motors freshen up the top end and a lot of times the let go after that. Everything was replaced with new parts except crank from site sponsor. He said it only had one season on it with very low hours & it came from his personal bike. Quote Link to comment Share on other sites More sharing options...
252wheelieking Posted March 2, 2012 Author Report Share Posted March 2, 2012 Id check water impeller. Or cooling system.. Thanks for the pointer...I will do that cause im as hell right now. it ran good the last time I rode it. it had good compression & all of a sudden yesterday the compression was low. Whatever happen had to have happen the last time i rode it but i didnt notice it. Quote Link to comment Share on other sites More sharing options...
252wheelieking Posted March 2, 2012 Author Report Share Posted March 2, 2012 this has happen to me in the past as well and it was my crank bearings that went. Your might as well go 4mill now since you will be changing out the crank. Yes im most definitely going 4mil cub now. Im tired of building this damn ss stock cylinder shit. Quote Link to comment Share on other sites More sharing options...
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.