I have a 91 yamaha blaster and the piston is seized. I got it for free, and was told that it would cost a lot for a shop to fix this. Is there a repair guide out there for this. Anybody know if this is a difficult repair to do? I would like to do it myself if its not too dificult. Yes I am a noob so go easy on me.

 

I think the easiest way to fix it is to load it on a truck and ship it to me [img]i/expressions/face-icon-small-smile.gif[/img]. Just kidding. It's not too difficult to do but figure that it's going to cost about $200 by the time you are all said and done. You need to remove the top end (the cylinder) and send it to a shop to rebore it and match it to a new pistion. You will also need new gaskets (head and base) and it wouldn't hurt to put in a new wrist pin bearing. If you can't find a shop to do it for a reasonable price let me know and I can give you some contacts for a few. Otherwise if you need any help with anything else let me know.

 

Thanks for the advice. Any info on where I could source the parts that I need?

 

You can find the gaskets and wrist pin bearing at your local yamaha dealer otherwise www.denniskirk.com should have them for a reasonable price. I would let the machine shop/speed shop get a pistion for you that way they can measure it and machine the bore to match the pistion perfectly with the proper clearance. Other than that take you time putting it all back together. Coat the cyliner with some two stroke oil and make sure that the wrist pin clips and piston rings are in the right position before you fire it up. Also make sure you break it in after you get it running before you really start romping on it. Be sure that you let it warm up before you start riding it. I would hate to put all the work and money into the thing to just blow it up again.

 

do not let it idle... be sure you are always reving it.. it doesn't have to be just constant.. just burp the throttle a little every couple seconds

 

A 91 Blaster, do you know if has been rebuilt before or how much it was ridden. The lower end may also need to be rebuilt to. Anyways redoing the top end and if worst comes to worst the low end is easy to do to. Here is a link to a online service manual and a article Rick Ritter wrote about cylinder boring for ATV Connection. He is a sponser of this site and does engine work and has the parts you will need. Also if you send your cylinder bored I would send the cylinder head to get milled for increased compression, it's cheap horsepower.

Cylinder Boring
Service Manual