Seized Piston?

[MachoMouse]

Seized Piston--rings plus??

Hi there...my engine seized a while ago..quite a few of you out there helped me narrow in on why...well, i've pulled off the head to look at the piston and so far I can see that one of the piston rings is split open and is loose on there...the other is not looking too cool either...the head seems ok, but the top of the piston has 3 small gouges in it...here's a couple of pics..can anyone help me with the next step?

 

[MachoMouse]

probably the culprit

well I dug around a litle bit more and down in the gap on the right hand side i found this little pin in there loose, can anybody tell me where he's supposed to go?

 

[MachoMouse]

Shattered wrist pin roller bearing

Hi, I posted before under "seized piston" but I think this requires a new thread...
I started pulling my seized engine apart and found that the roller bearing for the wrist pin has broken into a bunch of pieces, it has left three small gouges on the piston itself, which I'm not sure is too bad, the wrist pin has some worn or maybe dented indentaions too...I've only been able to locate one of the little pins and the outer edges of the housing, so i imagine everything else is hanging around 'down below' preventing the engine from moving...can anyone point me to link for pulling the engine apart enough to locate and remove all the bits and pieces? or is this engine junked?...it ran perfectly until it seized...
thanks
here's some pics to show you what i could find...

 

[Technocyclist]

well I dug around a litle bit more and down in the gap on the right hand side i found this little pin in there loose, can anybody tell me where he's supposed to go?

that's not a pin!!! it's one of the needles from the needle bearings!!! same thing happened to me!!! I suggest you replace the needle bearings with bushings...I've heard that engines that run on bushings are able to reach higher RPM's and less vibration, thus longer engine life... I have not been able to replace mine with bushings because I have'nt found a shop that fabricates it. Also, since you've already opened up the engine. I suggest you have the cranks balanced, and do some porting...

 

[srdavo]

bummer..... what does your cylinder bore look like?

is your engine new?

any warranty?

here's are the only links I know of, about splitting engine cases.... check them out & ask in those threads....maybe we can get some more info together.

http://www.motoredbikes.com/showthread.php?t=4836

http://www.motoredbikes.com/showthread.php?t=7972

new thread not needed....it's still a seized piston

 

[MachoMouse]

Roller bearing

Thanks Technocyclist...you are totally correct...the roller bearing shattered into tiny bits, i've only found the ends and one of the rollers...is this engine junk? or can i pull it apart and remove the bits?

 

[MachoMouse]

piston

Thanks SRDAVO I will check out those links immediately...I'd love to fix this engine rather than scrap it...unfortunately it's not a new engine, so no warranty...maybe 500-700 miles on it...is this what you mean by the 'bore'? the inside of the head is still very smooth...

 

[srdavo]

wow no scratches in the cylinder (bore)....where the piston came out?

lucky.

 

[MachoMouse]

Bore

yeah, the inside is very smooth still and the gouges on the piston are quite small...I looked at the links you sent me...the process sounds a bit beyond my abilities...I imagine that's the only way to get all the little pieces out huh?
If I have to get another engine, i'm going to look into the bushings that everyone's talking about...or maybe a more high performance version of the bearings, because 700 miles is a pretty crappy lifespan for an engine that i totally babied...thanks for your help..

 

[Technocyclist]

Thanks Technocyclist...you are totally correct...the roller bearing shattered into tiny bits, i've only found the ends and one of the rollers...is this engine junk? or can i pull it apart and remove the bits?

It's practically junk... for me, I just bought a new engine and just salvage what ever parts I can from the old engine... The only parts that can you'll find useful would be the crankcase and the clutch assembly. Better you replace the cylinder with steel sleaved one and replace the cylinder head with a smaller dome to increase the compression ratio. Then replace all the bearings in the crankcase with high quality and high speed bearings. But you'll need a very good shop who can do this... Probably Creative engineering or other Go kart shops...