New pistons

[motokid]

Hi everyone, I'm new to the site and these bikes but I'm 17 and just started my first build on one.

Anyway I picked up some stuff and a seized engine real cheap. I opened up the engine and turned out getting lucky because only one piston was seized but both were pretty carbonized. a valve was stuck open but the bottom end is in great shape.

The stuck piston got destroyed getting it out so I am just going to replace both and go to the next oversize and get it bored. It had the 3rd oversize so I am looking for suggestions on pistons. what do you guys think about these? I'm open to any suggestions

http://www.ebay.ca/itm/Yamaha-XS650-670cc-kit-with-pistons-and-rings-for-74-84-XS-650-HP-COATED-/330926300514?ssPageName=ADME:X:RTQ:CA:1123

Thanks for any help, I'll be on here asking questions a lot

 

[TwoManyXS1Bs]

Hey motokid, welcome to the forum.
Take your cylinders to the machinist who'll bore your cylinders. He needs to inspect to determine salvageability and bore size...

 

[Sonnylynnvick75]

Welcome man! I'm 21 so its glad to see some more young folks joining in. Like twomany said, Take the cylinders to your mmachine shop, try for an engine machine shop instead of just some random shop btw. If it had 3rd oversize and one cylinder is really boogered up you may be in need of new sleeves. If thats the case I highly suggest ordering everything from the same place, my parts choice is mikesxs.net but thats just me. I'm currently in the middle of doing a complete rebuild on an 81 so send me a message if I can help. Also, whoever you take the cylinders to would also be where I would take my head to have a valve job done. Get a price for the boring and a 3 angle valve job. You'll have to order valve guide seals as well if you're that into it. I'd also check that cam chain guide and cam chain. The Guide will probably need replacing and the cam chain itself wouldnt hurt either.

 

[TwoManyXS1Bs]

You go Sonny!

 

[motokid]

Thanks guys... Not too many machine shops around me and I don't think there's any engine ones. I have an independent guy do anything I usually need done like spacers but i don't know if he does engine stuff. the sleeves are actually in good condition no scoring just a ton of carbon build up around the one. Is there anywhere I could send the cylinders to have them done?

 

[XSLeo]

As was mentioned you might want to start by taking your cylinders to a shop. Let them inspect them. With your third over and one bore buggered a 4th over may not be enough.
There are plenty of options on your pistons. Several places sell a 707 cc piston set. Check out Hoo's Racing.
Another option if you really want to use those pistons is to buy a used stock bore set of cylinders and get it bored to match those pistons.
Leo

 

[Sonnylynnvick75]

Thanks two many. I don't know a whole lot but I'm learning more each day and I know enough to get me by lol

 

[Sonnylynnvick75]

Try finger lakes auto machine inc. I googled your location and searched for machine shops and it popped up so I'd call them and check to see if they did that stuff.