Piston question

[chesnut84]

I tore my cylinder off my warrior and I want to replace the piston rings. The piston is in good shape I am wondering who made my piston and whose rings can I buy for it. It's marked .040 over and the only other markings say 1ym. Any suggestions would be great.

 

[hammy7734]

add some pictures
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[lbjamm]

It's stock Yamaha. Just get some .040 rings and make sure to measure the end gap. But I would mic the cylinder while it is apart just to make sure you don't need to bore to clean up the cylinder.

 

[chesnut84]

I mis spoke. It says 1yw

 

[chesnut84]

 

[chesnut84]

I also checked the bore while it is apart it's .0003" from perfectly round. And .001 tapered from top to bottom. The finish is smooth. There's light vertical lines in a couple spots.

 

[alex456123]

No reason to replace the rings if you aren't re honeing or boring it out.
That's a factory Yamaha .40 over repacement piston.

 

[chesnut84]

I intend to hone the bore.

 

[lbjamm]

I would crosshatch and replace the rings.

 

[chesnut84]

Thanks guys is there a decent place on the web to order my rings? Tried ebay and there's a bunch of options. Not sure which to run with

 

[alex456123]

I'd go with Yamaha factory .40 over replacement rings over aftermarket.

 

[lbjamm]

http://www.partzilla.com/parts/detail/yamaha/YP-4GB-11610-40-00.html

 

[chesnut84]

Ok so I got rings in the mail and honed the cylinder. What it your guys opinion on .034" for the ring gap. I read it's supposed to be half that.