Ball hone or adjustable diamond hone?

[moburki]

Getting ready to put my motor back together, and I think I read Eric Gorr's site saying to use a ball hone on stock plating. The Wiseco piston instruction say do not use ball hone, and to use a diamond hone. What the consensus here?

BTW, I think I had the muckiest, most carbonized exhaust valves ever to come out of a KX5. Also had tons of blow by evidence on the piston. Its amazing it ran as well as it did. I'm pretty sure the thing has never had its head off in ten years!!! Can you say danger, shattering piston? I'll try to post pics of the dirty valves.

Thanks in advance

[hughes]

You can use a ball hone but do not use a diamond stone brake cylinder style hone. You will want to use a 280-360 grit ball hone. You just want to put a light cross hatch on the cylinder walls. I can't remmber but I think you will want a ball hone that 10% smaller than the bore.

Yamaha's Ring Free will take care of those carbon exhaust valves. Mine were so dirty that I just reinstalled them and ran ring free through the engine and removed the pipe after about two tanks and they were spot less.

[Brett]

I thought that you should use a diamond stoned hone for all of the coated liners as a normal hone won't leave enough proper oil retention qualities in such a hard lining material.

[moburki]

Thanks, I'll look for one at auto parts store (ball hone).
I have hard carbon deposits, enough that reinstalling the drum valves would be difficult. Is Ring Free a fuel addative?

[hughes]

Yes, Ring Free is a addative. The ball hone works great. It will leave a pretty cross hatch. Mine still has cross hatch after 20 hours or riding. The ball hone will not damage the port openings. The diamond brake cylinder type hones will remove to much material.

[moburki]

Well, I ordered a flex hone, forgot to specify grit...they ended up with a 120 grit. Too coarse.
Then worse, I found a dreaded crack between intake ports...I was trying to do a budget O-haul. I guess not. I guess I'll clean up the ports and send it out for welding and replating. Might miss more of our prime dirt riding season.

[hughes]

Make sure you use 2-stroke oil on the balls and lude the cylinder. The diamond brake cylinder type hones work best on sleeved cylinders.