Katit's 1978 KZ650 project

Engine apart (except flywheel - waiting for special tool)
Had to make special tool to remove needle bearing (and to reinstall it I guess)
Rough cleanup of parts to get oil and major dirt out.
Next to blasting. And not sure if I should paint or just leave it bare aluminum after bead blasting..

Nice bearing driver! I need one just like it to take mine out.

Some time with bead blasting. First time using glass beads. Not sure if this is result I should be expecting. Looks good but some oxydation very hard to remove. I use like 60 psi. Definitely better than it was, but now I am thinking about painting hard

It's called polish, not paint. Ed

Side covers maybe. But not sure, don’t have patience for this

If you are dry blasting you will have a duller finish. I use a friends shop where I dry blast the grime off and then wet blast for the nice shiny finish.

Wet blast, or Vapor Hone is the only way to go.

Mikaw wrote: Wet blast, or Vapor Hone is the only way to go.

If you have one - sure. I want to do as much as I can on my own. Wet blasted parts sure look great

So far (didn't measure yet) everything except head looks great.
Today took head off my "spare" motor. Now I know why it didn't turn.

But head - looks to be in great shape. All parts and threads there. No broken fins, etc. Looks completely serviceable. Some rust on valves which I don't think will be a problem. Some very small rust on cams. But I have another pair, hopefully will have a good pair picked.

You might want to run a bottle brush through your original cylinder to see if the marks on the wall come out. If not, in addition to the suggestions given already you have the option of looking for a clean used cylinder. I've rebuilt several similar engines this way with excellent results. Just be diligent when searching to make sure the new/used parts aren't also damaged/worn. You can use a 750 cylinder & pistons from a 750E or 750H too so keep that in mind.

Nessism wrote: You might want to run a bottle brush through your original cylinder to see if the marks on the wall come out. If not, in addition to the suggestions given already you have the option of looking for a clean used cylinder. I've rebuilt several similar engines this way with excellent results. Just be diligent when searching to make sure the new/used parts aren't also damaged/worn. You can use a 750 cylinder & pistons from a 750E or 750H too so keep that in mind.

Can you suggest specific bottle brush for 62mm?
This will be my choice #1 EVEN if it's going to be barely in specs.

Choice #2 will be sending cylinders to shop and get it bored for oversized piston kit.

What is the reason to go with "clean used cylinder"? Is it because it will be better than oversized with new pistons? Or because it will be cheaper?

I just spent over $1k for parts and it's engine only and not all. I want to make sure bottom end is 100% and even if I need to revisit top end later it will be not a big deal, can be done on a bike. I want to make sure I like to keep this bike first.

www.enginehones.com/212240sc.html

Used cylinders & pistons are much cheaper than going the bore & new pistons route. Success depends on finding good used parts though of course.