Suzuki 2 Strokes

My 74 GT750 is running great after being in storage for almost 30 years.
Problem is: left cylinder, when it's running, is running much colder than the middle and right ones....
Eventually, the plug will foul...when I pull it out, it's black...the others are a nice true butterscotch color.
I heard it may be the SRIS lines...somehow resulting in too much oil in that cylinder--baking it to the electrode, shorting it out? Does this make sense?
Can anybody explain this to me, or help me at all?
Many thanx!

That will depend on whether it is wet fouled or dry. Wet usually indicates too fuel rich, also if it 'gooey' it could be oil fouled. I would almost eliminate ignition problem, it sounds from your description, I have been fooled before. Also check the exhaust baffle, it may be plugged up causing extra back pressure, it could even be a bad crankseal. A leak down test might need to done. There are sooooo many things it could be, everything else can cause the same problem, it will be a test of your patience checking to find the problem. Two strokes have a lot to work with for being a simple engine!?

You do have the choke lever in the off position right?
Don't laugh, I rode a GT550 for years, and the first time I was on a 750 I rode a 25 mile round trip and almost did not make it home due to fouled plugs. Because I was riding it with the choke on.

The reason? The on/off positions of the lever for the choke is exactly backwards on the 74 750, compared to the 76 550.

Kevi

also check the float level on that carb all that sitting could have a small pin hole in it. Or just might be out of spec. Also check the spark cap could be going bad or coil