700 pistons

Charlie P

Charlie P

Member
Joined
Mar 1, 2020
Messages
57
Location
Springfield,il.
I have a 01 SX700R with 8,000 miles on it. It runs good but I'm tempted to tear it down for rings and check the pistons for wear. Can't seem to find any Yamaha pistons or rings for this machine. Has anyone used SPI pistons and rings with luck? How are they compared to stock? Don't want to wait till winter and find out it needs an overhaul. SPI says their rings will work on factory pistons. Anybody done it?

Thanks Charlie
 

Thanks for the link. I'm going to tear it down to inspect before ordering parts. It will get new rings at a minimum, If the pistons are in good condition. I've never owned a 2 stroke sled with 8,000 miles before, don't know what to expect. Think I'll do a leak down on it before I do anything. The guy I bought it off of said it ran great and didn't need a rebuild. As we discussed that during negotiations. I've heard horror stories about breaking piston skirts and punching them thru the case. Sure don't want to chance that.
 
Measure the pistons while you are in there. That will tell the story.
In a Yamaha tech manual, there are specs for wear limits on the piston, and where to measure it at.
 
I feel that those are good pistons, and have used them in a Ski doo before.
But I would rather have the Yamahas myself.
 
Look at this, couldn't believe this. [
I also got a complete gasket set from amazon for 13.27 plus 5.99 shipping. I thought what the hay, I can always send it back. It came today, complete set, I went to go order another set and they were $125.00. Don't know what the deal was there. When I paid for those pistons with paypal it only came out to $85.00. Don't have a clue, but hope they come in like the gaskets did. I'll put the new parts in anyways for that cost. If they come in and are good I'll order another set for my other 700 engine.

I have deleted the link as I have found out it was a phony web site. I have been refunded by paypal.
 
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Not 100% sure but think they a nicasil coated. Never found any over sized pistons for it, so pretty certain they don't over bore them.

Think that site I linked to above is a fraud. Can't get no info on it or anybody to answer my emails. Turned the site into paypal so we'll see. In the mean time I took a cold compression check on my engine. 132 lbs on every cylinder, never ever seen an engine so close together on compression. Don't think I'm going to do anything to it. Sure can't believe a 2 stroke with 8000 miles could have compression as even as this one. Now I'm wondering if maybe it has already had a topend done.
 
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Correct, cylinders are aluminum, then Nikasil plated.
Cant overbore, unless they are replated, or have a steel sleeve inserted.
 
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