84 big red 200 Issues

[HON-DUH]

Working on getting an old 200es big red going. Initially found that the o-ring between the carb and spacer block and the o-ring between the spacer and the head were both missing. Installed new o-rings there so as to seal it up. Installed the correct spark plug because it had the wrong one in it. Went through the carb and everything looked good. Got the bike running but it seems to be running rich and also the idle hangs and jumps around and then it quits shortly after getting it running. Played around with the needle setting and moved the clip all the way to the top to address the rich condition. Now it will run a bit longer but still has the erratic idle as if it is sucking air and then when it quits the spark plug is sooty and fouled. Not sure what else to look at here. Any ideas would be appreciated

[350for350]

For the running rich part, check to see if your air filter is clean. Also check your complete intake (including the frame tube) and exhaust for obstructions. Mud daubers LOVE to make nests in the frame tube and that will block off part or all of your incoming air.

[HON-DUH]

I took your advice and looked into the intake and exhaust. I blocked up all of the frame tube where it brings air in except a small hole and blew compressed air through to the air box and it was wide open. Checked the exhaust and had good flow there also. Thanks for the suggestions