Unknown, but nearly 70k KM's on the frame. I have done about 15k KM on the engine since I bought the bike. I'm glad I didn't wait any longer to get stuck into it.
light hone may be needed and ring gap should be in line with the little end gudgeon pin and no end gaps directly in line.
Yes, light hone and flog the ring piece out of it when you get it running. None of that running it in nonsense.
Those bores look to be fine.. measurements will confirm or tell you how bad they are.. but if you cant feel a lip at the top then you should be pretty right.. the exhaust ports are an entirely different matter..lol It will be interesting to see how the CT18 works on that carbon buildup..
Also, check the manual when you're putting the rings on the pistons...the old 120 degree rule doesn't apply.
Head soaked overnight again, changed the water this morning and at lunch time. Did it one last time after I finished work for the day and let it soak while hot, as I was cleaning up the valves on the wire wheel. The water turned black after I came back and scrubbed the the ports with a stiff brush Drained it out and there was a lot of chunky carbon floating around Ports are starting to look a bit better, I can see alloy in a few places The pistons were in the ultrasonic all day with fresh water/ct18 mix again, this time they came up beaut. There are some marks which probably correspond to the ones on the cylinders, but I didn't think they were this bad before. Possibly the pistons were touching the cage in the ultrasonic cleaner? Onto the valves. A 'before' shot of an exhaust valve. After
Bad news. Head has cracks. You can see it in the first pic in my last post. There is at least 1 crack on all 4 banks, some have 2. Need to finish cleaning it up and decide what I'm going to do with it.
Okay so you have to remove all the seats, weld the head, re-thread all the spark plugs, and machine and install all new seats. If you are going down that path I would use 8mm spark plugs to get the extra meat. This is a specialist job. In Brisbane, Liddle's Cylinder Head Engineering used to be capable of this type of work. Not going to be cheap.
There are some on the inlet sides, this one on #4 looks fairly deep, about 3 threads or so. I don't know how this head didn't drop the seats. Two cracks here Another two here, diagonally opposed, a bit hard to see Another two the same Two more, one inlet one exhaust
Dollar wise, get another non cracked head. To repair will cost more than your whole bike is worth, but most things can be fixed with enough time and money.