Did Stev60 solve his problem.? It sounds very similar to my problem.
I have been out on the newly-restored engine of my 1961 GF, and the smoking has not decreased much. It is occurring only on the left cylinder.
I will describe what is going on, and see if anybody could suggest my next steps:-
The bike has now done two x 20 mile runs, so I think if it was just seating of rings the smoke should be bugger-all by now. The first run was with an 18-tooth engine sprocket (too revvy) and the second with a 21-tooth (much better). It seems to have great power - not that I have tested it much.!
After starting cold- wait about 30secs to 1 minute and the smoking starts. A little at first, then after another minute it gets fairly heavy white smoke - therefore presumably oil. Then it starts to drip from the pipe-muffler clamp, and smoke comes from there also. On my first outing, a mate followed (on a 1954 Norton Model 7 Dominator) in case I needed transport. He told me that once I get riding, the smoke decreases such that after about 10 miles it was fairly light, and by the time I got home it was hardly visible, only after throttling back and then re-accelerating.
On the second outing, the smoke started he same, but rode on my own so cannot say how visible it was.
This morning, I started it for a mate, and the smoke started exactly the same as described.
I drained the sump both times, and got about 150mls so wet-sumping does not seem to be an issue.
There does not seem to be any oil loss from the breather. The rear of the crankcase is clean. I am running it in with Penrite HPR 30 20W-60 and I have fitted a Norton-type oil filter. The oil has high zinc and no friction-modifying additives according to the blurb. The oil pump seems to be working OK. Oil pressure is 60psi cold and drops to 40psi when hot, and the return oil flow looks great, with typical entrained air bubbles.
The head was not restored. I remember removing the valves about 25 years ago to lap them in and to check the guides and I was able to get a little movement. To assess the guides, I got Robertson Brothers in Newcastle NSW motor repairers to dismantle and give me a second opinion. They knew their stuff, but said the guides were OK. However, two years ago and still not being confident, I asked a bloke to dismantle and check the motor and also the valves and guides, and his opinion was also that the valves and guides were OK. Clearly they are not new, but it doesn't seem that they are worn enough to blow clouds of smoke.
The oil is getting a bit dark with carbon but still quite green, and the SRM-style magnetic sump plug is also layered in carbon - no gritty stuff though. Nothing to be alarmed at yet.?
The plugs are sooty, but I thought I would put a few miles on it before trying to tune it.
I think my next step is to check the rocker banjos to see if the orifice sizes are OK. But does anyone know what I should look for here.? How big are the orifices for a standard GF.??
If the orifices are OK, my next step is to pull off the head and cylinders and check for cracked oil ring on LHS and re-check the valve guides.????
Colin