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2007 800r Top End Rebuild

2K views 14 replies 8 participants last post by  Mr. Lee 
#1 ·
I decided to start a new thread. Yesterday I got my new MCB top end rebuild kit and I have a few questions.

1. I think it is called the wrist pin. When I install it into the piston and caged bearings, should I lube it up with something. I was thinking motor oil should be okay?

2. When I install the gaskets, do I need some sort of sealant too? For the skinny and non-rubber gaskets.
 
#6 ·
Well, the normal ski doo protocol says a thin coating of Locktite 518 anaerobic sealer on the base gasket. We use a coating of Vaseline (Petroleum Jelly) on the head gasket O rings to help them seat into place. Both are good practice to insure no leaks in these critical areas.
 
#9 ·
On lining up pistons to cylinder walls.... it's 2 circles; one goes in the other.
If you mean compressing the rings to slide in the cylinders, you can get a harbor freight motorcycle piston ring compressor; they are different than car ones. But, some do it with hose clamps and if you're gentle, you can just kind of cock it a little (barely) sideways and push the rings in with your fingers.
Ring end gap, direction and where you put the gap is critical. And make sure you put the base gasket on first.
 
#10 · (Edited by Moderator)
Rotate crank so one piston is up about 2 inches more than the other. Keeping cylinder square with the case, lower cylinder onto 1st piston (the one that's up the most obviously), compress top ring with fingers, cylinder will drop on, then compress bottom ring and cylinder will drop on. Repeat for second piston. Easy on the bench, little more difficult in the sled. Be patient.
 
#12 ·
Thanks guys for all the comments. So if you remember I did not remove the engine. It is hard to balance the cylinder walls and compress the rings at the same time. I got MCB pistons. Do they have to be in a certain position to fully compress?

I will try some of your suggestions:

1. Be more patient and use your fingers to compress the rings

2. Piston ring compression tool. An automotive 4" one is all I saw on Harbor Freight. http://www.harborfreight.com/4-inch-piston-ring-compressor-97709.html

3. Call Mike. Whats your favorite beer/pizza/sandwich/rec. weed/etc.
 
#13 ·
Thanks guys for all the comments. So if you remember I did not remove the engine. It is hard to balance the cylinder walls and compress the rings at the same time. I got MCB pistons. Do they have to be in a certain position to fully compress?

I will try some of your suggestions:
1. Be more patient and use your fingers to compress the rings
2. Piston ring compression tool. An automotive 4" one is all I saw on Harbor Freight. http://www.harborfreight.com/4-inch-piston-ring-compressor-97709.html
3. Call Mike. Whats your favorite beer/pizza/sandwich/rec. weed/etc.
Same process in the sled. Ring gaps must be lined up with locating pins on the intake side. Help is always a nice thing to have if available. ????
 
#14 ·
Rotate crank so one piston is up about 2 inches more than the other. Keeping cylinder square with the case, lower cylinder onto 1st piston (the one that's up the most obviously), compress top ring with fingers, cylinder will drop on, then compress bottom ring and cylinder will drop on. Repeat for second piston. Easy on the bench, little more difficult in the sled. Be patient.
I also use my fingers to compress the rings. I have a ring compressor for 4 strokes, but with two strokes I find it is far easier to use my fingers.
 
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