Topic: replacing the rings

[eigenvector]

A little scary just how easy it is to remove and replace the rings on a 550.  While probably not the preferred method, simply grabbing it with needle nose pliers is sufficient to spread them apart enough to slide them off.  I'm glad it's easy, but it sure is uncommon.

I noticed the 2nd oil ring was broken on the #2 and 3 pistons.  Fortunately I have a scrap engine to scavage from.

As to installing the pistons, I'm using a hose clamp as a ring compressor and lowering the cylinder onto the piston.  Is that not a good idea, should the pistons drop into the cylinder and the install the wrist pin?  Seems like the bottom of the cylinder sleeve is beveled to alllow installation from underneath.

[flybox1]

ring compressors, like you are using, work just fine.
just be sure the clamps have no burrs scratching the pistons as you slide them down.  I used a thin plastic strip between the rings and the clamp...
light oil on the inside of the cyl helps, too...
new rings would be preferrable.

[eigenvector]

Check the clearances on the rings?  I don't know where you do your work, but I wrench on my bike under the shade of a tall tree.   (Actually that's a literal truth, it sits under a big Douglas Fir).  Your comment about the rings is understood, I'm not really worried about it for the moment, this is an engine that I'm doing some testing on.  The bike doesn't even have a wiring harness.

That said, I have a new bottom gasket and rings on order for when I do put it all back together - properly.

[eigenvector]

Testing, when I say testing I mean turn the crankshaft by hand.

Remember that post I made a long while ago about printing a new cam chain return guide?  Well I have a bunch of prototypes and I'm just manually turning the engine to check fitment, see where and if they're hanging, where they're likely to wear, small tweaks.  Not even sure why I bothered replacing the oil rings, other than I saw them and it bothered me.

[eigenvector]

Let's say I do remove the pistons, can you substitute snap rings for the wire retainers that are used right now?

Personally I find snap rings easier to install than wire retainers - but I have snap ring pliers.  Seems like those wire retainers always want to shoot off in random directions, typically just before you're about to finish.