My worst nightmare?

This past winter break when I was home from college, I took off the oil pan b/c I had to rethread the oil drain plug. I pulled off the pan and found two decent size chunks of metal(sorry no pics). They fit together and when combined were about the size of half-a-penny(a penny cut in half). My father and I both concluded that it was a part of the piston skirt. The goodnews is that there were no metal shavings of any sort. Anyway I was hoping somehow I would just forget about this and everything would work out fine, but I've realized that probably isn't the case. The engine has never burned any oil and I have ridden it since this incedent.

So pretty much to sum up, how screwed am I? I bought the bike for $200 and have invested about $500, so it wouldn't be the biggest loss in the world.

Thanks for the help,
Nate

Could it be the core of one of the cam cover plugs? Maybe it got chewed up on the way down or something..seems like the right size.

Have you opened it up to look at the pistons?

I have not opened it up yet. I'm not sure what the cam plug core looks like, but these pieces had a curvature of what would be appropriate for a piston.

. . .must. . . post . . . some . . . pictures. . .for . . the. . . imagination . . impaired . . . because . . . our . . . diagnositic . . . skills . . . are . . .

crippled . . .


The literal sense is the gruesome 'to cripple (someone) by cutting the hamstrings'; though not found in the historical record until slightly later, it must be the original. The sense development is paralleled by the example of cripple itself, which originally meant 'to make a cripple of; lame' but then developed a figurative sense 'to make nonfunctional; hinder; thwart'

I won't be able to post pics as I am still at college so for the sake of converstation I'm going to trust my dad(he was a race-boat mechanic, 2-strokes I know but close enough) on the fact that it was a piston skirt. So what do you think is going to happen?

the worst thing will be a rattle in the engine, which will in time go from bad to worse when the piston breaks, but that could be a long time depending on how you ride. and it will smoke some from the rings not being able to seal well.


Just had a thought, could this be from a previous repair?, and they never pulled the pan to remove the broken pieces?

If the oil pan is off, can you look up at the bottom of the pistons to see where it came from? Maybe you can replace the one piston, or like BSK said, maybe it's from a previous repair. You could verify it by looking at the pistons.

Yea, I tried that at the time but with the crank and oil pump,there was to much junk to get a good view. I'm have no idea on it being a previous repair I have only had the bike for a year and a half.

Post edited by: Shoey949, at: 2007/04/19 15:24

At the risk of sounding like an idiot, from your description it sounds like you may have come across the remains of a choke flapper. The TK carbs are famous for losing these things and nobody seems to know where they end up. You may be the first to actually find one.:S

I would love to have that claim to fame, but I'm 99.99% sure that it is not a choke flap, it definately apprears to part of the piston skirt.

BSKZ:
I have noticed a rattling that I can't remember from when I first had the bike. What is the physics behind the rattle, is it because the piston is out of balance? Also what is going to happen to the engine when this piston craps out?

Post edited by: Shoey949, at: 2007/04/19 18:32

It probably is part of the piston skirt, and piston skirts usually break because of excess clearance between the piston and the cylinder bore. I am surprised that it is not burning any oil though.

As to what could happen, it depends on exactly how the piston breaks, maybe it will just make more noise, maybe it will be a catastrophic failure, no way of telling until it happens.

Probably the best idea would be to get a top end gasket set and pull the top end off to see exactly what's happened.

steell wrote:

It probably is part of the piston skirt, and piston skirts usually break because of excess clearance between the piston and the cylinder bore. I am surprised that it is not burning any oil though.

As to what could happen, it depends on exactly how the piston breaks, maybe it will just make more noise, maybe it will be a catastrophic failure, no way of telling until it happens.

Probably the best idea would be to get a top end gasket set and pull the top end off to see exactly what's happened.

agreed

a 60 dollar kit and a case of beer wont hurt anything, however riding it and just shrugging it off will.

and if it is a piston skirt then you can stick a big bore kit in it for some fun:evil: