Curious if it's a no-no to try to vapor blast the jug and head while still attached to the lower end (If I can even find a place to do it). The engine is off the bike and I would obviously block the intake and exhaust manifolds and bag and tape the bottom end the best that I can with spark plug installed. I have the next 7 days off and hoping to reinstall the engine without having to tear it down and wait for new base and head gasket to arrive. Would love to know what others do in this instance. 

I wouldn't recommend it, depending on the pressure water and debris might get past seals and gaskets.

I don't even use a pressure washer to clean my bikes

 

Thanks for the confirmation. I’ll just pull off the head and have that blasted, do the jug by hand and anneal the copper so I can move forward. I’d like to take a look at the cylinder anyway. 

You say you've already removed the engine, so go ahead and remove the cylinder, have it vapor honed, and then you'll be able to sleep at night without wondering if you had crap blown into your motor. Nothing like a good night's sleep. 

Thanks for the advice. I already pulled the head off. I see a few vertical scratches on the cylinder wall and the piston moves enough side to side to make a small tic. Piston looks pretty clean through the exhaust port but I’ve  already reached out to Enduronut to see about picking up a new piston and ring set. Will plan to order a piston pin, upper bearing and circlips. Will check the forums to see what size piston I have. 

Top of piston is always somewhat "loose". Skirt clearance is what's important.

Make sure to pay attention to part number prefix on piston, rings, and pin if you end up replacing them.

You should check the bore before ordering a new piston. Kind of the cart before the horse. Probably needs bored to next size. You can’t tell with the naked eye. Visiting your local engine builder should be in your future.

Wish I could easily post update pics on this RT3. I decided to forego doing a top end for now since I did the frame off before hearing it run. Got the jug and head cleaned and the lower painted. Didn’t have spark but got some advice to disconnect the key switch wires and was able to get spark. Tried to find a shirt and must have fixed a bad contact as I now have a fully working ignition system. First ride, engine sounds tight and has plenty of power. Lights, blinkers and horn all work too! I have a few things to tinker on but other than tanks and headlight painting this project is mostly done. I’d wanted to get a 74 or 75 but so happy to finally get a 360 again.