1982 GS650G problems

[Magoo]

I own a 1982 GS650G. It has roughly 16,000 miles. Oil change was around 1400 miles ago. Just did a 1200 mile trip.

The problems I am encountering as thus.

#2 pipe from left side facing foward runs colder than others. Compression is normal. Spark is present. Carbs are calibrated. Caps are new. Spark plug had oil on it and had residue around hole but seemed to be old and has not returned since cleanup.

Medium amounts of white smoke are coming from the left side pipe. It seems to happen when bike is warmed up, particularly at stops.

Bike feels starved at high speeds.

I am going to change the oil before I ride it again and replace the fuel tap as soon as possible.

Are the any suggestions to the cold pipe and oil smoke? For the oil, maybe it is just in the pipe and being burned off over time? Should I remove and clean those? Also, any long term problems with a colder burning cylinder?

Thanks if you have any helpful suggestions.
Magoo

[Magoo]

**update**

I took the bike for a quick ride as I was missing it.

Afterwards, oil was all over the undercarriage and it was generally running poorly.
I noticed that the oil levels from the sight glass were more than they should be, which made no sense since it appeared to be leaking.

I discovered that the fuel tap's vacuum tube runs directly into the #2 cylinder. If there was a leak through that it would explain the cold pipe as it was getting flooded with gas and not igniting properly.
It would also explain the higher levels of "oil" in the sight glass combined with the overflow. It was filling the case with so much gas it was venting and pushing oil out and everywhere.

I am going to be ordering a universal non-vacuum tap instead doing a rebuild on the vacuum tap that had the problems. Once that is done I'll do a thorough oil change. Clean the oil off the undercarriage and be on my way.

On my Vespas if there is a problem with the tap there is just bad flow, or no flow, or it floods and you have a gas w/ 2-stoke puddle. That's what threw me off. The tap was something I had been wanting to replace for a while but couldn't see how it was related to this problem.

Magoo

[mark]

Sounds like you might have it figured out. Sucking gas through the vacuum line is a common problem.

Good luck on figuring out where all that oil is coming from!

[Magoo]

**fixed**

Removed the vacuum hose from the #2 carb and replaced it at each end with a vacuum cap. I am using this as a temporary fix as I have go out of town for a few days and need a freeway bike. So, now Prime is ON, and everything else (On, Reserve) is OFF.

Oil change completed. Much gas in it.

After a week of riding, I will do another oil change just to be sure.