prb Posted October 8, 2012 Report Share Posted October 8, 2012 Has any body else had a piston ring rotate and catch the exaust port? This just happened on my banshee.I did a full rebuild 2 years ago always ran great, but I was out the other weekend and I had to start choking it to get it to start even when warm. It would run great after it started.Then I was sitting for a moment with it idling bliped the gas twice and it shut down,well I just tore it down and the left pisto ring rotated and caugt in the exaust port.The locating pin is still there. It has wiseco pistons in it and a wiseco crank basicly a stock rebuild with pipes asnd k&n .I did a leak down test before I tore the top end off and it passed with flying colors 6psi for 6 min.just wanted to make shure I had no air leaks ,thinking that is why I had to start choking it to start .It probably was from low compression. Quote Link to comment Share on other sites More sharing options...
Dahl87banshee Posted October 8, 2012 Report Share Posted October 8, 2012 Was the piston for the right bore size? Almost sounds like the ring wasn't tight enough to the ring clip. I had it happen twice with my Vito's super stock pistons. Wasn't sure why because they matched the bore size. Quote Link to comment Share on other sites More sharing options...
SAVAGE420 Posted October 8, 2012 Report Share Posted October 8, 2012 Piston rock or ring end gap too big ect. Quote Link to comment Share on other sites More sharing options...
prb Posted October 8, 2012 Author Report Share Posted October 8, 2012 (edited) Was the piston for the right bore size? Almost sounds like the ring wasn't tight enough to the ring clip. I had it happen twice with my Vito's super stock pistons. Wasn't sure why because they matched the bore size. Yes it was .I gave the pistons to the machine shop before they bored it and I have had them do about a dozen other cylinders for me 4 and 2 stroke over the years and never had this happen or had a problem with their work.I have over 2 years on this motor since the rebuild(my son rides this one ) he said my motor lasts longer because I ride like an old man ha ha . My banshee has 6 years since last top end is still strong . Edited October 8, 2012 by prb Quote Link to comment Share on other sites More sharing options...
prb Posted October 9, 2012 Author Report Share Posted October 9, 2012 Detenation can cause this. you say detonation will cause your ring to skip around your ring pin and rotate (how) Quote Link to comment Share on other sites More sharing options...
Man-O-Steele Posted October 9, 2012 Report Share Posted October 9, 2012 is the pin still in the piston? Quote Link to comment Share on other sites More sharing options...
prb Posted October 9, 2012 Author Report Share Posted October 9, 2012 is the pin still in the piston? yes the pin is still in and only the bottom ring spun Quote Link to comment Share on other sites More sharing options...
joey83 Posted October 9, 2012 Report Share Posted October 9, 2012 Did it break the ring? I just had something similiar happen and somebody pointed out that the ring broke qnd then spun around. It caught on the intake port. It was my own fault bc I just threw a completely stock used top end in it just to make the bhq ride and the ring end gap was a metric mile wide. Stupid and costly mistake. Curious what was the compression on the good cylinder before you tore it down? Quote Link to comment Share on other sites More sharing options...
prb Posted October 9, 2012 Author Report Share Posted October 9, 2012 (edited) Did it break the ring? I just had something similiar happen and somebody pointed out that the ring broke qnd then spun around. It caught on the intake port. It was my own fault bc I just threw a completely stock used top end in it just to make the bhq ride and the ring end gap was a metric mile wide. Stupid and costly mistake. Curious what was the compression on the good cylinder before you tore it down? The good cylinder s compresion was like 60 but my guage must be bad because it wouldn't even had run if it was that low .Update I just took of the other jug and that bottom ring was also turned around almost to the exaust port. But when I looked close at the ring gap you could see how thin the ring was worn, almost down to the dished part that goes over the pin.I sure my problem was the top end just wore out and gave the rings enough room to rotate past the locator pin.Thought I should get more than 2 years out of a top end ,also I clean the air fillter every ride it is a k&n and run golden spectro oil 40:1 same as my other banshee also premium gas Edited October 9, 2012 by prb Quote Link to comment Share on other sites More sharing options...
Paulie B Posted October 14, 2012 Report Share Posted October 14, 2012 I didn't even think that was possible with the pin still in. Quote Link to comment Share on other sites More sharing options...
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