bansheeryder21 Posted February 26, 2007 Report Share Posted February 26, 2007 Here's what happened. Let me know if anyone has ever experienced this!!!! I got my motor ported a few months back! I had the cylinders honed and was still at stock bore! 64mm. I bought brand new wiseco 64mm piston rings for a fresh top end! Pistons were in great shape as well as the cylinders! Looked brand new except the bitchin port job I got done! Well after everything was put together, the bike ran great and was fast as hell! Just what I expected! I had about 4 or 5 trips to the desert with that motor and wanted more power. So I was going to get shearer pipes and a bigger port done. (Mine you, the bike is still running bad ass. took it out last weekend) Well I sold my T-5's and was ready to tear the motor down. I pulled it apart yesterday. This is what I found: On the left side, the lower piston ring snapped. One end of it bent down about 1/4 inch and was pressed into the side of the piston. That cylinder is now cracked at the bottom of the intake port and the intake port is gauged in all four corners. That cylinder is ruined! On the other side, the bottom piston ring managed to spin itself around, moving the opening of the ring where the little pin goes, to the other side. Thus making the piston ring wider than the cylinder! Every port on that side is gauged and the exhaust port is the worst! Both cylinders are ruined. No bore can fix these. I have no idea how this happened! I used 64mm rings on a 64mm cylinder. I made sure I measured the gap in the piston ring. The bike was running rich, so I know I didn't burn anything! Has this ever happened to anyone before? I posted some pics! Here's the link: http://s106.photobucket.com/albums/m261/ltzryder21/ IF ANYONE HAS STOCK CYLINDERS THAT THEY ARE SELLING OR KNOW OF ANYWHERE I CAN GET SOME FOR CHEAP, PLEASE LET ME KNOW AND SEND A PM MY WAY! I NEED ALL THE HELP I CAN GET! THANKS! Quote Link to comment Share on other sites More sharing options...
thegroup Posted February 26, 2007 Report Share Posted February 26, 2007 just have them re-sleeved Quote Link to comment Share on other sites More sharing options...
trex banshee Posted February 26, 2007 Report Share Posted February 26, 2007 looks like to me the clearances were too big and the piston had too much room allowing for excessive front to back movement causing the ring to come out further catching the exhaust port. I had this happen before on a set of stock cylinders i used to have, the bore was just simply too big for the pistons. Quote Link to comment Share on other sites More sharing options...
BigRed350x Posted February 26, 2007 Report Share Posted February 26, 2007 There is a possiblity that your cylinders were not true on the bore. Bigger on the bottom or on the top and when the piston got to that point, the rings had enough play that they could move and when the piston would travel back up the cylinder wall it fucked ya. There's all sorts of stuff that could have happened. My guess is the cylinders were not true or something along those lines. Also, how did they port them and not bore them. You would usually bore the cylinders after a port job... Quote Link to comment Share on other sites More sharing options...
FireHead Posted February 26, 2007 Report Share Posted February 26, 2007 just have them re-sleeved Re sleeving is no big deal. If you are wondering why that happened I would be willing to guess that the exhaust port was opened up to wide, the allowing a ring to hang. Thus, you get a result like you seem to have had. :thumbsup: Quote Link to comment Share on other sites More sharing options...
trex banshee Posted February 26, 2007 Report Share Posted February 26, 2007 I would be willing to guess that the exhaust port was opened up to wide, the allowing a ring to hang. Good point here :thumbsup: . Didn't think of that, obviously you can see how far the ring isn't supported. Quote Link to comment Share on other sites More sharing options...
KlotzBanshee Posted February 26, 2007 Report Share Posted February 26, 2007 Now I'm no expert, so I may be wrong...but I don't think you should have used wiseco rings in the stock pistons. I believe the stock pistons use two diff thickness rings for top and bottom, and wiseco pistons' rings are the same size top and bottom. plus the champhurs on those ports don't look the best, from what I can tell from a blurry pic /or my blurry eyes Did you break her in good before you hit the desert? :shrug: Quote Link to comment Share on other sites More sharing options...
thegroup Posted February 26, 2007 Report Share Posted February 26, 2007 see, mine did this back in nov. it busted both rings, and what u see on the piston is the way my jug looked. also busted the piston off on the intake side (got lucky and didnt hurt my crank) if u just have them re-sleeved, u wont be wasting all that money from the port jobs Quote Link to comment Share on other sites More sharing options...
FireHead Posted February 26, 2007 Report Share Posted February 26, 2007 Now I'm no expert, so I may be wrong...but I don't think you should have used wiseco rings in the stock pistons. I believe the stock pistons use two diff thickness rings for top and bottom, and wiseco pistons' rings are the same size top and bottom. plus the champhurs on those ports don't look the best, from what I can tell from a blurry pic /or my blurry eyes Did you break her in good before you hit the desert? :shrug: Wow, I spaced that detail. You are 100% correct, Wiseco pistons are made from a forging while the stock units are made from a casting. The CTE of the material are greatly different in respect to the application, thus the rings are made to different shapes and dimensions (I am not sure how noticeable it is). Good catch! :thumbsup: Quote Link to comment Share on other sites More sharing options...
CadillacBanshee Posted February 26, 2007 Report Share Posted February 26, 2007 Same thing happened to a friend of mine twice before he realized that his exhaust port was way too wide. Quote Link to comment Share on other sites More sharing options...
FireHead Posted February 26, 2007 Report Share Posted February 26, 2007 see, mine did this back in nov. it busted both rings, and what u see on the piston is the way my jug looked. also busted the piston off on the intake side (got lucky and didnt hurt my crank) if u just have them re-sleeved, u wont be wasting all that money from the port jobs Interesting, piston ring generally fail more often on the exhaust side of a two stroke engine's piston as it is quite a bit hotter. I wonder why that happend to you? Quote Link to comment Share on other sites More sharing options...
bansheeryder21 Posted February 26, 2007 Author Report Share Posted February 26, 2007 On the side that the piston snapped, it didn't catch the exhuast port! It caught the bottom of the intake port whiched cracked. I don't think I can resleeve with it being cracked like that! The other side, the bottom ring spun around creating bad clearance and gauged out every port on that side! Now I know for sure it wasn't the exhaust port and I know it wasn't because of the port job! Kevin Herr has been porting for years and know what he's doing. He has ported plenty of bikes the same way and with even bigger exhaust ports and has never seen this! If asswhore is correct, then make sure we post out on HQ for people not to buy wiseco rings with stock pistons! PLEASE LET ME KNOW IF ANYONE HAS STOCK CYLINDERS UP FOR GRABS! Thanks! Quote Link to comment Share on other sites More sharing options...
FireHead Posted February 26, 2007 Report Share Posted February 26, 2007 If you are properly motivated you can fix anything. If the crack in the cylinder is weldable, weld it, remachine it, toss a new sleeve in it, and you're done. :thumbsup: Quote Link to comment Share on other sites More sharing options...
bansheeryder21 Posted February 26, 2007 Author Report Share Posted February 26, 2007 (edited) If you are properly motivated you can fix anything. If the crack in the cylinder is weldable, weld it, remachine it, toss a new sleeve in it, and you're done. :thumbsup: The left side is cracked and un fixable! There is nothing wrong with the crank! The crank is already trued and welded. I am just going to try to find cheap used stockers! Edited February 26, 2007 by bansheeryder21 Quote Link to comment Share on other sites More sharing options...
trex banshee Posted February 26, 2007 Report Share Posted February 26, 2007 If asswhore is correct, then make sure we post out on HQ for people not to buy wiseco rings with stock pistons! Asswhor is correct, the bottom rings on stock pistons are thicker than the top ones. Quote Link to comment Share on other sites More sharing options...
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