pushrod seal replacement questions

[ssls6]

I've got a couple of questions concerning the replacement of the
pushrod seals. I've read all the info I could find on the internet
but there are a couple of points I would like clarified.

1) what is the best way to remove carbon deposits from the piston and head? I have removed the piston from the cylinder and connecting rod.

2) I'm using both a big o-ring and yamabond 4 for reassembly. Should I coat only one surface or both with the yamabond? I would guess coating only the cylinder surface would produce the most uniform "thin" coating but I need some advice here.

3) I know some use oil, others silicone grease, and yet others use adhesives on the outer pushrod seal surface so it sticks in the conical hole better. I have some yamabond 7 (rubber to metal adhesive) and I wonder if there is a reason not to use it on the outer seal surface?


Thanks in advance for any words of wisdom.

[yukonairhead2]

Greetings, I replaced the pushrod seals last spring and used yamabond on both surfaces, but only a thin coat - no leaks. As for the carbon, I took the heads, pistons to a local machine shop and had them checked and cleaned I think it depends on how well your shop is set up. I could not have cleaned them up as well as the machine shop - for a 26 year old bike they look brand new and it was a cheap process because I had it all apart.

Have fun! Mike

'81 R100RS

[stardw]

(1) I let the piston top and head cavity soak in simple green for 2 hours. Used a brass brush to remove the carbon deposits. Piston cleaned up nice, the head could have been better:

http://i30.photobucket.com/albums/c338/stardw/Bike/TransmissionRemoval075-R1.jpg



(2) I only coated the cylinder base with a thin layer of Permatex Gray. Nothing on the engine. Cylinder base O-rings were also required. Be careful around the top stud o-rings with whatever sealant you use. Oil the o-rings prior to assembly, and be quick about it. They will swell.

http://i30.photobucket.com/albums/c338/stardw/Bike/TransmissionRemoval078-R1.jpg



(3) Use engine oil on the inside and outside on the seals. Just a small amount to help assembly.

Attached is a link to Snowbums (http://www.cdegroot.com/cgi-bin/mirror/pweb.jps.net/~snowbum/pushrodseals.htm) site on this subject. You may want to purchase Oak's Top End manual. Lot's of good info. I replaced my seals last month. No leaks so far. Good Luck!