Source of Smoke?

[rickt]

The bike is a '78 GS750C. Just recently completed a total "cosmetic" restoration and a fair amount of mechanical work. Bike has 2000 original miles and was parked since 1981.

Carbs were completely rebuild including a couple of needle tips that had to be align drilled out. I did not replace the boots as they seemed to be in fine shape. Bike starts easily and settles to a nice idle when warm. Hesitates badly from a start, but once moving runs pretty well.

Cold start-up produces a fair amount of smoke from the right pipe. Also, some popping until choke is off. Smoke almost disappears when bike is good and warm.

Tried to check the compression using the kick-start only (installed DynaS ignition and was afraid of damaging it). Got 60-70 psi on all four cylinders. I know this is very low, but maybe due to failure to use E-start?

Looking for suggestions on where to start with diagnostics. Not excited about going into the engine. Hoping there might me a simplier, less expensive fix.

Thanks,
rickt

[hampshirehog]

Smoke when cold and clearing when warm is a classic sign of worn / hardened valve stem oil seals. You can either live with it - won't do any harm - or pull the head and give it an overhaul.