gatesy Posted May 9, 2005 Report Posted May 9, 2005 I hope you're 'touching wood' as you say that! Don't you think it's time you at least changed the rings and wrist pin bearings? Does what you see above not tempt you to replace your pistons aswell? Rare. 366798[/snapback] Mine is an '04 , and the pictures are nearly enough for me to start replacing stuff hope you get her back together soon!!!! Quote
Rare Scottish Tree Badger Posted May 9, 2005 Author Report Posted May 9, 2005 I hope so too! Thanks gatesy. Rare. Quote
Klotzban1 Posted May 10, 2005 Report Posted May 10, 2005 No, it's not good. ... There's a real mess inside the cylinder. I've taken a few pics and will get some more up in further posts.Oh shit, u mean all that came out of the exhaust? I think that would make me throw up. It was all just lying in the front pipe when I removed it from the cylinder. And yeah, I'm not feeling too good about this. Here's the first few of the pics: I've pulled the head and the bad side doesn't look too bad. Should clean up ok. (That's a NEW plug in the bad side. I just put it in there for washing the engine). Surprise, surprise, I still have two pistons! ... But both are at the top More interesting stuff to follow. Rare 366110[/snapback] YIKES!!! that isnt good at all.....check her out good. Those really look wore out. Quote
XxMeltIcexX Posted May 10, 2005 Report Posted May 10, 2005 Runnin 6 years on a set of stock pistons and rings is pretty fookin' amazing if you ride hard... light at that... U just jinxed urself tho... it's bound to happen.. i'd change them before you do yourself more damage... Quote
wayfst Posted May 10, 2005 Report Posted May 10, 2005 sorry 2 c that. i've heard of cold seizure, but dude, holy crap. top of the piston sticks and yanks the wrist pin out! imagine the force it takes to do that. it's not dead till it's in the ground. Quote
lincster Posted May 11, 2005 Report Posted May 11, 2005 Sounds like you got a better set of pistons and cylinders out of Yamaha than most people. Six year old bike with 140 psi is pretty good, what was your starting compression with that cool head? 366909[/snapback] About 152 with my 20cc domes. Quote
lincster Posted May 11, 2005 Report Posted May 11, 2005 Runnin 6 years on a set of stock pistons and rings is pretty fookin' amazing if you ride hard... light at that... U just jinxed urself tho... it's bound to happen.. i'd change them before you do yourself more damage... 367134[/snapback] No worries. I just built a LS1 powered sand rail. The Banshee just sits in the garage now. Quote
lincster Posted May 11, 2005 Report Posted May 11, 2005 Ok, no need to be sarcastic. ... I don't believe that briefly giving the bike full revs with no load was the cause, it should have coped with it. But doing that when not up to temperature probably WAS. It's not something I would usually do and like I said, I have been so frustrated with my sticking slides that I thought I had cured that problem and wanted to check. I was just too impatient. ... "My stupid fault". I don't wish bad luck on you, but 6 years on original rings is asking for trouble. ... Rings wear, and to me, changing them periodically is 'preventative maintenance'. Rare. 366888[/snapback] If my rings were bad, I would have low compression. Quote
Rare Scottish Tree Badger Posted May 11, 2005 Author Report Posted May 11, 2005 Update: Spoke to my engine builder today. ... He's managed to save the cylinder by boreing out to just under 1mm. I'm not exactly sure what he means by that, as 1mm is 0.0393" . If it's out to 0.75 mm then that's 0.0295". Anyway, Wiseco pistons going in it now. I need to send down the crank to have it checked out and have the bearings and bent rod replaced. I wish this flywheel puller tool would hurry up and arrive so I can get the cases split! He said that if I had seen the piston before this, I would have seen lots of crack marks which is why the piston broke up into so many pieces when something failed. He also reckoned that the damage had been done on the previous running, which was my plug chop run. So I guess this was going to happen anyway. I forgot to send him the bottom ring and wrist pin with what's left of the wrist pin bearing, so he'll work out what failed when he gets the crank and these other bits. Rare. Quote
SANDSTAR Posted May 12, 2005 Report Posted May 12, 2005 That stock head might give you trouble if it isn't resurfaced. All those dings and nicks will give you hotspots. Might be time for a coolhead with some high comp-domes. Quote
Rare Scottish Tree Badger Posted May 12, 2005 Author Report Posted May 12, 2005 (edited) He's done, or is going to do a clean up job on the head. He told me it would be fine, so I'll trust him on that. I just scored a complete bottom end from an RD(RZ)350 today, so that gives me a crank and rods. ... Just need to get it welded when it arrives. I'll probably get a coolhead at the end of the year, when the funds have been replenished a bit. In the meantime, I've got 'Engine Ice' to go in on the rebuild and I'll fit a temperature guage. Rare. Edited May 12, 2005 by Rare Scottish Tree Badger Quote
Jdawg82 Posted May 13, 2005 Report Posted May 13, 2005 That is exactly what happened to my piston on my bike, looks exactly the same piston blown to pieces and all. The funny thing is my spark plug on that side was finger tight. I contribute that to my piston failure. It seems as though it is the same thing that happened to yours. Quote
Rare Scottish Tree Badger Posted June 3, 2005 Author Report Posted June 3, 2005 Hey Guys, Shee's back in business again! Fired up on 3rd kick. ... It's quite a scary moment after such a major rebuild eh! Just switched off from her 1st 5 min session of idling. ... If it lasts through Sunday's MX race I'll be chuffed! The RZ crank was a bit out of spec and I didn't have it trued and welded, so I don't know how well Shee's going to go or how long Shee'll last. I just couldn't afford the extra expense. ... Fingers crossed. (False economy, I know, but needs must! ) Only had to take the cylinders out to .040 (from .010) and there's Wiseco Prolites in there now. Show me the dirt!!!!!!!! Rare. (and saved from extinction! ) Quote
dajogejr Posted June 3, 2005 Report Posted June 3, 2005 Good to hear...RSTB. Good luck in your motoing!! Quote
BANJO Posted July 4, 2005 Report Posted July 4, 2005 what did u do to clean up your head i have the same problem small nicks from my blown up piston.. and i dont really have the money to buy a new head.??? peace devin Quote
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