well i found out what was wrong!!!!


New Member
Aug 14, 2007
Well when i put my posts on here to ask if i was ready for a rebuild and how to get the swingarm bolt off( still not off, but took the tank off and took the head out that way) I found out that my piston shattered! Now how can i get those little chips out? The Bore is still mint!:-D!!!!!!!!!

Now since i have the motor out im redoing my whole blaster. Paint, parts, motor rebuild etc

let me know what you think


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the enigine block has to be split if u want to do it right, same thing happened to mine before it was rebuilt
can i take it in and have it cleaned? Or use a high powered air compressor?

i dont want to split the cases, but i really want it clean!:-D
If that piston shattered like that you will need to split the cases to get any fragments of piston out. Unless you want your tranny or crank to lock up
Yup it sucks

Splitting the case is the only way to get crap out and be sure. It really isn't that big a deal if you stay focused and organized. Drop a little coin on a good manual and if you have the tools just take it all apart, clean her up real good and replace the bad crap.

yes, if you score your piston or break pieces off of the piston it is a good idea to clean the cases out
so to split the cases i pretty much just take it all apart right?

any pics of a split case or ppl doing this?
If you dont have the tools, the manual or have ever done anything like it, I wouldn't suggest that you do it yourself. It would probably be better to have your local shop do it.
well what special tools do it need?

is it pretty much taking everything off cleaning and reassembling?

I agree with flyers. Unless you are prepared, it ain't a OJT kinda thing. I have pics, well can take them and pretty sure i have a manual that came with my ride I can give ref. to. It's a whole system, though, and you need to understand the big picture. It isn't like a statistics course, but, it is specific.

It also needs to be pretty dang clean. A couple chunks of piston, sand sized, can make a nasty mess fast.

A guesstimate

To have the top end rebuilt and get the bottom cleaned I'd figure $400-500 bucks. I base this on the fact that I bought a bike in the same boat and that was the quote the the shop gave the last owner. That was splitting the case and cleaning, new jug and rings, new wrist pin and clips and bearing, gaskets and I think the boring/honing on the cyl. and the labor to do it.

I said "OUCH".

How much was it exactly? I wont need the cyclinder rebored because its perfect! All i need is the cases split, cleaned, and top end rebuilt

how much do you guys think it will be

ive got 550 to spend
well if you rebuild the top end completely you should at least have it honed to set the rings good. Cases split and cleaned was about 180 in labor and a total of 240 with all the seals and gaskets that needed to be replaced. But every shop has different rates. So the best way to get a quote would be to go to your local shop and ask.
Also check atv repair shops that are not yamaha dealers, cause private repairs shops are usually cheaper. If you have one near you anyway.
you will need to bore it because the reason the piston shattered is excessive space around the piston commonly refered to as piston slap, I have seen this hudreds of times and when the piston breaks its usually in decent size pieses and you can just wash them out with diesel fuel turning the crank over and over flip the motor upside down and blow it out with compressed air. if when your done the crank spins nicely your good to go! theres really not enough room in the case for anthing to get hidden and it does not go anywhere near your tranny, thats comletely seperated on two strokes.
"I wont need the cyclinder rebored because its perfect!"

how much do you guys think it will be

ive got 550 to spend

How are you so sure your cylinder is "perfect", my freind has a YZ125 that wont run no matter what he replaces, his cylinder is out of round, it looks good to look at it, but its not enough compression to run and he swears up and down thats not it, and thats his LAST option, just because it looks ok doesnt mean its ok, it doesnt need scores or deep scratches to be needing a bore/hone. it kan look smooth as glass and be 1-2mm out of round, enough to make problmes, piston rock being one of them, after so much of this you kan skirt your piston as you already have

and 550 at a decent shop should do it, it was 600 for my old quadracer and that was another left case and a complete rebuild plus a couple odds and ends, and new internal bearings, some things you kan buy yourself to save a tad bit of money and then just take it to them to have it done,. parts including, piston kit, gaskets, seals and what have you, another thing to eat the cost of and get done is new crank bearings, kause you kant go wrong with new crank bearings, and have your crank trued while your at
Be sure that your cases aren't cracked where the connecting rod travels. Splitting is the only sure way to see that.