keeping oil ring from overlapping

I put new rings on my bike last night, and put the pistons on the rods in preparation for sliding the block on tonight. One thing that kept me from putting the block on last night was the fact that my expander rings seem to have a propensity for overlapping, which my manual explains will cause oil burnage. Are there any tips for keeping the ends from overlapping when I slide them into the cylinders?

patience! :laugh:

PLUMMEN wrote:

patience! :laugh:

x2....and being VERY careful.

You can use large, screw type pipe clamps, to compress the rings and hold everything in place. Just need a couple as your doing 2 pistons at a time.
Makes things pretty easy... if your careful, and patient.

The last thing you want to see as the rings go into the bore is that they are not overlapped. Once in the bore they can't do it.

Tips to make that job easier.

1- If the oil expander rings are not painted, get two different color paint sticks and mark the end of each expander ring so you can see better.

2 - A generous chamfer on the cylinder sleeve will help the ring guide in smoother. Most times when a block has been bored, the chamfer is either gone or marginal. I always use a die grinder and a K-Roll to put that chamfer back in there. Make sure you re-prep the block if you've already prepped it once and are going back in to grind the chamfer.

3 - As was mentioned, large hose clamps make good ring compressors but you have to watch a couple of things.



a] Using some 400 paper, sand the inside surface of the clamp so there are no burrs. Those little slots where the screw grabs the clamp can have burrs on them that can scratch the rings & piston.

b] Apply oil on the inside of the clamp and also to the rings.

c] Apply oil to the bottom of the bore, up to about your first knuckle.


Position the end gaps of the oil expanders on which ever side of the motor [front or back] is easier for you to keep an eye on]

Thanks larry, my block has not been bored so there is still a nice chamfer and my rings have green and red paint on either side of the oil ring end gap.

I have seen videos on Utoob of people using compressors on car pistons, where they put the compressor on the rings, then take the piston, which is not on a rod, and use the end of a hammer to gently tap them into the bores sliding them out of the compressor. Would I just compress the rings as tight as I can where I can still slide them off, then insert the pistons into the bores, and once I have everything lined up and set just slowly pull the clamp down the piston while I drop the block on top? Would this make things actually any easier than just being really careful and doing it without the hose clamp?

you can use the clamps just be carefull trying to compress the rings,and dont scratch piston skirts with them

Fwiw, here's the factory tool for Z1~KZ900.

Am doubtful as to application for overbores, and don't know what's in the plastic bag.

Good Luck!


[Click on image to enhance view]

Stock cylinders with stock pistons will go together without any hose clamps or ring compressor...fairly easy, using your fingers and something to push on the rings.

Just take your time and think positive when you're doing the job.

If you take on any job and have negative thoughts in your mind......it goes much harder. Seriously, think positive!

In the plastic bag in the photo above are piston support wires. The slide under the skirts and would help you greatly with installing the block.....I have had those for many years.

The KAW OEM Ring compressor is bulky to handle IMO. I've used it before and prefer fingers or hose clamps.

Hose clamps work great if you take precautions to prevent scratching the pistons and just use a little common sense.

Install hose clamps so the top ring land is above the clamp. That gives the sleeve something to get hold of so the block starts down properly without rocking the piston all over.

Snug the clamp, then when block is sitting on all the pistons, hold the block down with the palm of your hand and loosen the clamps 1/4 turn. Use a mallet to begin tapping the block down. Start in the center. Tap it evenly and watch as you go.

One all 4 pistons are up in the bore far enough so the rings can't pop out, get the clamps off. It gets a little tight for space once the block is down that far.

hmm, interesting. to be honest, after hearing how to use the clamps properly I think I will try it just with my hands and a chop stick. I have a buddy there to help me out so I will have a nother pair of hands to move the block down for me. I will post results hopefully tonight!

With a friend to help, it will make things much easier for you. The weight of the block itself assists things generously. If everything is nice and lubed, the pistons will gently wiggle right in with a little force.

Its not really that hard. In fact, the most difficult part for me is maintaining a meticulous ring spacing while holding the block on either side from above, and using my fingertips to pull the piston up into the cyl. :laugh:

Good luck.

hmm, interesting. to be honest...

Are you implying that you were not honest previously!
:woohoo: :laugh: