Black plug, black smoke

[Jere]

Ok, some good, some bad.

I took the choke cable apart and successfully lubed it with WD40 using the cable luber I got. Success! It worked well. I can actually move the lever without straining. So, this was definitely a huge part of the problem. It seems to be running good now, except..... (will get to this later.)

I also changed the air cleaner. The old one was dirty as heck and saturated in gas. I'm assuming this is because the engine was constantly flooding and gas vapours were pouring out of the vent tube that leads from the carb to the air cleaner? I took out the drain plug and almost 3/4 cup of water/gas came pouring out of the air cleaner housing. I don't think that's normal but am sure it's a symptom of the bad choke cable.

So, I've got it running fairly good except one problem. When I shut it off it backfires something fierce. Also, when I rev it then quickly let off of the throttle I can here a bit of a "put put put" as it comes down to idle speed. Also, when I got back from a ride and the engine was hot, I noticed it was idling quite a bit faster.

Stuff you should know:
- i haven't set the idle speed because I figure I have to fix whatever else is wrong first. (also, I don't have a tachometer.) I mean, I haven't set it properly. I adjusted it "by ear."
- It's still full of premium gasoline, or 1/2 full anyway. I haven't put and carb cleaner in the gas.

So, i guess the question is: "what's the next step?" The service manual doesn't mention backfiring. I'm trying to do the "easy" stuff first.
- carb clean?
- valve clearance check? (thanks burkbuilds for good advice on how to do this!)