Best Pistons for Summit 700-On a Budget.

[Backcountrypro]

Best Pistons for Summit 700-On a Budget. Pic Added

I am helping a friend rebuild his 02 700 Summit and I would like to know what piston kit would be good to use. He is on a budget. I checked my High Performance Engineering catalog and I could get a piston kit for roughly $52.00 each. That sounds really cheap to me for a piston, ring, circlips, and piston pin. Has anyone used these cheaper kits? Where can I find caged bearings to replace the old cageless bearings? Thanks.

 

[dieseldog800]

Contact Big John here on the forum. He'll help steer you in the right direction.

 

[Crasher]

Stock 670x pistons are the ticket. Turns the 700 into a 700HO

 

[Zachmandu]

I've ran the cheap, moly-coated SPI/kimpex style pistons in my 670 with twins for about four years of hard riding...with no problems. If your clearances are right, you will not have any problems running the cheaper pistons.

I can't recall the caged bearing part # at the moment...

 

[V-Man]

When do most people replace them? I'm at about 3k miles on my 700 and its still running strong. I've never done a pressure test or taken a peek at them through the ports. I used to replace them yearly on my 2-stroke dirt bikes.

 

[Backcountrypro]

Ok I found a MCB kit. Everything we should need including gaskets and caged bearings for a little over $200. This would be a moly coated, dual ring piston. How about going this route?

The 670 piston mod sounds good, but I want to keep things simple on this one. Ok so this sled has been torn apart for over two years. My buddy says everything has been covered and packed with rags and is clean. Any precautions I should take going into this?

I have the failed piston that can from the motor. To me it looks like a four corner score, possibly cold score. My friend started the sled when it was really cold and I don't think he gave it enough or any time to warm up before driving it out of the garage. Once out of the garage he said he let it warm up but about 5-10 miles down the trail the motor lost power.

I will post piston pics later.

Thanks.

 

[Backcountrypro]

700 Summit Rebuild-Piston Pic

Here is a picture of the bad piston from this engine. It looks like a four corner score to me, but I am no expert. I noticed on the top of the piston on the exhaust side there is some kind of splatter, it feels just like the splatter that you get when welding. I am thinking it is some of the melted aluminum from the piston but maybe someone know for sure why it is there. Well thanks for any advice.

 

[Backcountrypro]

ttt

 

[WannaB]

I ran the spi pistons in my 2000 700 and they ran great, not a lick of problems...Check your base gasket size, I remember increasing to a thicker gasket and I wanna say it was a five or six hole...check around but I doo know that after the rebuild and base gasket change the 800 couldnt out doo me by much even on the hills. Also make sure your epoxy glue the buttons on the ends of the dpm sensor box so they dont leak and cause other problems. I miss that sled it was a great one, has 3500 miles on spi pistons and still runs strong...