bad piston, bored?
- Thread starter badluck91
- Start date
Oh. Well .4972mm over on the cylinder bore is .0196" over. The problem with that (and I'm going to have to assume your friend can measure) is that it is not quite ,020" (but damn close) Either that bore is perfect or very worn. The only way to tell is to measure the piston at it's largest point. That should be on the skirt somewhere (I think near the piston pin but not positive). If you find that the piston is only a couple thousandths (1-2) smaller, then you are golden. If it is a big diff, like .010-,012" or more then it's shot and time for and overbore.
Can you still see diagonal crosshatch lines (honing marks) on the cyl wall? This would indicate a fairly fresh bore.
Have you looked at the manual? It has a very informative section on teardown and inspection for a rebuild, as well as how to clean up the piston if it measures ok.
www.rydindirty.com/blastermanual.pdf
Can you still see diagonal crosshatch lines (honing marks) on the cyl wall? This would indicate a fairly fresh bore.
Have you looked at the manual? It has a very informative section on teardown and inspection for a rebuild, as well as how to clean up the piston if it measures ok.
www.rydindirty.com/blastermanual.pdf
If it was me I would put a new piston and rings in it. If you question wether the piston is good or not might as well throw a new one in there to save you from having to tear down again and have to bore when that old piston shatters in there. And make sure the crank has little to no side to side play. I didnt check that on an old rebuild and suffered dearly when i had to do a top and bottom rebuild only 2 weeks later.
all cranks have side to side movement, up and down is whats bad.
yeah but who knows where he measured that cylinder at you know. actually you would take 6 measurements. x-y axis. top,middle and bottom. if i was him i take it to a shop and ask for there opinion. why throw a new piston in something that your not sure of and waste money or cause more damage.
I was noticing in your pics that the right thrust washer on the crank looked a bit thinner than the left. could have just been the pics but are there any gold looking shavings anywhere. if so the crank is probably going. be sure the crank is good or you will be wasting your money on whatever you buy to fix your piston probs.
the pics of the piston indicate detonation to me and or something coming apart in the botom end of the engine. does the surface of the cylinder head look about the same?
the piston should be smooth on top with a bit of carbon build up and not looking like it was cleaned by dragging it accross a concrete driveway.
the piston should be smooth on top with a bit of carbon build up and not looking like it was cleaned by dragging it accross a concrete driveway.
i was thinking that too but its hard to tell from those pics. pretty frickin blurry! kinda made me dizzy. lol!
This week I'm gonna take it to a shop and get it measured again... The piston looks rough as hell also but the crank and all looks fine.. Their are no scratches in the sleeve of the cylinder whatsoever, it dosent seem worn or anything.. The guy that I got it from was like the 6th Omer of this bike and god noes how long this same piston has been in their..
https://iphone.ebay.com/Pages/ViewItemPic.aspx?pix=1&aid=250698553131&emvcc=0
Anyone ever do this, are have and good r bad things to say about doing this??
Anyone ever do this, are have and good r bad things to say about doing this??
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