Top end rebuild

[Trails Boy]

So i went to have my cylinder measured and it came out at 66.03mm and was told i need a 65.98mm piston... Problem is I've only been successful in finding one that size on ebay (new) made by pro-x specified for a crf-150 would that work? If not Wiesco makes a 66mm piston... Would that work?

[Julien D]

Is this the 87? If so, that is within factory spec. You can put a std wiseco in it and be fine, or a pro-x b/c/d.

[rbates9]

A four stroke piston won't work in a two stroke.

[Trails Boy]

Yes its the 87. So your saying the pro-x that i sa on ebay will work?

[Julien D]

Yes its the 87. So your saying the pro-x that i sa on ebay will work?

If it's a STD piston, it will work.

[Trails Boy]

How do I know if its a STD piston?

[Julien D]

The listing should say if its standard or oversized.

[Trails Boy]

It does not say Guess I will need to keep looking

[Julien D]

Link?

[Trails Boy]

http://www.ebay.com/sch/i.html?_nkw=Pis ... acat=10063

[david]

Instead of searching for that size piston, search for one for your spacific bike.

[gopack4749]

https://www.denniskirk.com/wiseco/pro-l ... M06600.sku

https://www.denniskirk.com/piston-assem ... stid=68911

http://www.rockymountainatvmc.com/p/44/ ... Piston-Kit

http://www.rockymountainatvmc.com/p/44/ ... Piston-Kit

I think any of these should work.

[Julien D]

Instead of searching for that size piston, search for one for your spacific bike.

Exactly. You just need a standard KDX200 piston. Same part from 86 and up I believe.

[Trails Boy]

Okay! That helps so much! Thanks!

[Trails Boy]

The 66mm would be the best since its the biggest right?

[Julien D]

The 66mm would be the best since its the biggest right?

66mm is just the stock bore. The piston will actually mic out a bit smaller than that. Wiseco does not do incremental sizes, pro-x does. I think you're over-thinking. If you want forged, standard size is your only option. For a cast, you could go with a standard C or D pro-x which is very slightly over size. Not enough to make a difference imo.

[Trails Boy]

Okay.. I just went with the Wiesco 66mm.

Thanks for all the help!