Rebore or hone

[doubleextramayo]

In the process of a top end rebuild on an sohc 400. So the jugs are off the bike and after a visual inspection, I'm not so sure what the status is. When I take it to the shop, should I ask for a rebore or just a hone? And can I get away with ordering just new rings (oversize or standard) or do I need new pistons as well?
Sorry if pics aren't the greatest.

 

[rshutchinson]

Well they will measure and if in spec then just a hone and new standard rings. The specs are in the manual, I don't know them off hand.

If out of spec, I'd get new pistons in the oversize you can find rings for as well. Oversized rings and pistons I don't believe are easy to come by. Then take the jugs and pistons to the shop and have them bore it for those pistons.

 

[BBS360]

It all depends on how badly the cylinder is worn.
If the crosshatching from the previous honing is still visible on the cylinder walls you might get away with the bare minimum.
If the cylinders look perfectly flat, no crosshatching, you'll want to have the bores measured first and go from there.

Edit: Dave beat me to it.

 

[doubleextramayo]

Thanks for the quick responses guys. I'll bring it to the machine shop this weekend and see what they say.
So anyone out there in xs400-land know of a seller that has oversize pistons? I know oversize rings are available off of ebay but I haven't looked into pistons much.

 

[rshutchinson]

There are a small few of the first oversize pistons available on ebay right now.

Pistons:

http://www.ebay.ca/itm/YAMAHA-XS400...ash=item1c51af5457:g:dDcAAOSwstxVNsK6&vxp=mtr

http://www.ebay.ca/itm/YAMAHA-XS400...ash=item5686396708:g:4JAAAOSw2GlXLAs1&vxp=mtr

http://www.ebay.ca/itm/NOS-Yamaha-P...ash=item1c4f6f41ef:g:u7QAAOSwZjJU9P99&vxp=mtr

http://www.ebay.ca/itm/NEW-YAMAHA-X...ash=item2ee0ab6536:g:ZlMAAOSwPgxVOn5F&vxp=mtr

Rings
http://www.ebay.ca/itm/NOS-Yamaha-1...ash=item542b2ae5ba:g:skoAAOSwll1W1bXp&vxp=mtr



Or here is the whole thing, pistons, rings, pins and circlips

http://www.ebay.ca/itm/Yamaha-XS400...ash=item1eb15c80a3:g:x24AAOSwH6lXQxeS&vxp=mtr

 

[esmith87]

www.scheuerlein.de, stuff is legit. I've ordered from them, and always get what I ordered. Just run the URL through a website translator first