Piston install tips

Toyotech

New Member
So I'm rebuilding my CB350f motor and almost to the point of setting the cylinders on the bottom end. I've build plenty of automotive engines and have ring compressors of all sorts of sizes, just not small enough for the 40mm ones in my bike. Any "substitute" ring compressor tools you've used?
 
I've found using popsicle sticks works well, just get the crank lined up so all the pistons are level and lock it in place however you can, then lower the block over the pistons and use the stick to get the rings in as the block comes down. works especially well when ring compressors are really just too big to use on these tiny motors
 
Yeah get someone to help you out.
I did my 400f by myself and it sucked.
Just did a gs550 with a friend and it went together in about 2 minutes flat.

No ring compressors needed, the cylinders are chamfered, just squeeze the rings with your fingers and slowly lower the clys on.
 
Use a couple wood blocks under your first two pistons square to the bore and start working the rings in with your fingers. Then once those are started pull the blocks and the other two will raise up into location as the cylinder comes down and you then fit the outer two pistons...

1981CB750K329.jpg
 
Hoosier Daddy said:
Use a couple wood blocks under your first two pistons square to the bore and start working the rings in with your fingers. Then once those are started pull the blocks and the other two will raise up into location as the cylinder comes down and you then fit the outer two pistons...

Outstanding, many thanks!
 
I have done it by installing the pistons in the bore first, just enough that the rings are in the cylinders, and the pistons are hanging out of the bottom far enough to slip the wrist pins in.
 
Alpha's route is really slick too, but if you go with that pack clean shop towels in the case bore first...
I spent an hour one time years ago with a case in the parts washer with the oil pan back off trying to flush out the wrist pin circlip I fumbled an dropped down in cavern below. ::)

So... about that Commando... you got it somewhere here?
 
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