Boring/Honing

[tother]

Hey Everyone - new to the forum. I recently got my hands on an ATC 200. Seemed like it was leaking oil between the cylinder and the cam's (head gasket I believe).

This will be my first attempt at a rebuild, but I have studied the manual like its going out of style (:

Anyways few questions.
I am from Mississauga, Ontario and I have called everywhere trying to find a shop/machinest that can bore the cylinder for me. So far un-successful. The piston, rings and cylinder appear to be in good shape, but everything I read says if you are going to do it right that you will need to get it bored out and get new rings/piston to match. Is this really needed?

Next question is valves - I have ordered replacements off ebay as well (why not while im doing it)... The manual starts to get a bit confusing when it comes to valves. What is really required to change them properly?

[beets442]

Welcome, Others might disagree but I say no, its not needed. I've reringed several times without boring. Ask them to measure the Cyl. and piston, it might just need a hone and rings. Take your head and valves to them too and have them matched. I've used automotive machine shops too.Good luck Beets

[ratvespa]

there is no yes or no, in your manual it will give you the max runout specs on pistons clearance, and ring end gap clearance. You should check those while you are in there. is the piston is OK, and the rings are little bit towards the end of the spec, go ahead and toss in some new rings. Make sure you get to the right rings, ie if you have a standard piston, use standard rings, 1st oversize, 1st over rings. Some times you can clean the top of the piston off and it will be stamped on it, some times you have to measure it. If it looks like its never been open its probably standard.
Now, if you do put new rings in it, you want to give it a light hone, it's easy, and the hone tool is pretty cheap.
http://www.amazon.com/Engine-Cylinder-Hone-2-7/dp/B000I12TY6
or the better option is to measure the bore (or look it up in the service manual) and order a ball hone, they are about the same price, but will only be good for that size cylinder. FOLLOW THE INSTRUCTIONS ON THE HONE!!!! do not hone for too long. you are pretty much "breaking the glaze", google how to hone a cylinder.

yes you can use your stock pistons and rings, but my logic is, why you are in there...why not?

also, if the piston is out of spec, you will need to go to an oversized piston, and have it bored out. You might have to mail it to a machine shop, search around on line. most all auto machine shops will do it.

finally. CHECK YOUR RING END GAP OF YOUR NEW RINGS. I cannot stress this enough. here is a pdf write up.
http://www.wiseco.com/PDFs/Manuals/RingEndGap.pdf
they show a ring gap grinder, you can do the same thing with a file

[tother]

I am thinking about sending it to one of the online motor shops. Get the cylinder bored with matching piston and rings. Also send the cylinder head with the new valves and have them seat them properly.

Will simplify the re-build. Any suggestions on places to send it?

[bcredneck]

if you want to do it your self and theres no serious damage hone it with a brand new drum brake honer if it has damage it will
cause it to lube it with 2 stroke oil and hone untill the glaze is gone and put rings in it must be de glazed or it will not brake in properly i did this with my xr75 2 years ago it still runs good now

[bcredneck]

if you got the head off polish the exhaust port and use 600 grit on the intake the air turbulence from the roughness mixes the air and gas better its a noticeable difference in power

[camoweasel]

G&H ATV Discount Supply They are out of Tennessee I believe and do wonderful work. I just sent in my 350x cylinder and it came back less then 2 weeks later bored, honed, and bead blasted to an individual piston. Pretty sure they have rebuild kits for about all ATCs. I highly recommend them. IT cost me about 220 for shipping, machine work, piston kit, and gasket kit.

[atc500x]

I can bore your cylinder,I have a boring machine and honing stone.40$ for the job + shipping,I'm in quebec so shipping isn't expensive.Let me know,you just have to send me the cylinder and the oversize piston

[tother]

Thanks ATC500x will keep that in mind -dont suppose you do Valve jobs too (: ?

Another question. It doesnt look like mine has been taken apart before, but i only see 3 dowel pins. manual if I am counting right shows 5.
Took a look at the lubrication and it appears that the one shoots the oil to the top of the cylinder, but there wasn't even a dowel pin there? starting to get confused at how the oil gets up there at all.