So I guess I’m replacing the head

[Steve]

There are several techniques for getting the barrels back over the pistons. I prefer some wood blocks and hose clamps.

You will want to use wood blocks to support the pistons when installing the head - there are threads here about using them and I will try to to see if I have any pictures otherwise I'll get some this weekend.

Here is what is pictured in the Clymer 850 manual:


Not so sure that those dimensions actually work, you have to measure between the studs to make sure it fits between them.

I have never bothered with hose clamps. The bottoms of the cylinders are tapered/beveled, so simply squeezing the rings with your fingers will be enough to shrink them down enough for the cylinder to slide down. It is a test of patience, though, as you need to start with the top ring on #2, then go to the other side of the bike to do the top ring on #3. Continue with the second ring on #3, then back to the other side of the bike to get the second ring on #2. Continue with the oil rings on #2 and go to the other side of the bike to get the oil rings on #3. It helps considerably if you have someone helping you with this, but it's still a test of patience.

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[alke46]

I found it a lot easier to just use hose clamps on two and three but have them just barely snug enough so that you can tap the top of the piston down until the rings are all in the bores. Just takes a little bit of patience.

[Dan]

Thanks a lot for the tips guys. Super helpful group.
I found some guidance on reinstalling the barrels on YouTube as well.

https://www.youtube.com/watch?v=DeDjQk5Hpio

The pistons are off. I think they look terrible but maybe you guys know better. It does appear most of the carbon comes off fairly easily, but I haven't gotten into it yet.

https://photos.app.goo.gl/UkYCvtPvVWEXEFc26

I'm going to start a separate thread on the rebuild.

Thanks again, Dan

[Grimly]

The pistons are off. I think they look terrible but maybe you guys know better. It does appear most of the carbon comes off fairly easily, but I haven't gotten into it yet.

https://photos.app.goo.gl/UkYCvtPvVWEXEFc26

That's just carbon. What matters is what wear marks (if any) are on the sides of the pistons and in the bores. You'll need to invest in a set of digital calipers and some bore gauges - both of which are available cheaply enough to provide some measure of reassurance. Mostly, the cheap ones are accurate enough to work with, but there are some lemons out there. Iow, it needn't cost a lot to know exactly where you stand with it. Chances are, if the pistons and bores look undamaged, you will get away with a simple hone and new rings, but you won't know for sure unless you measure them up.

[Dan]

Thanks Dave, the pistons and walls look good, at least to me. I'll confirm the measurements and get the rings.