Need a little help. Rig has ran flawlessly since I bought it, a bit more than a year ago. No choke, electric or manual, unless it’s automatic mechanical. When cold, I’ll pump the gas once and it fires right up. It’ll idle around 1200rpm until I pump the gas again and it goes to idle around 500rpm. When warm, when starting, one gas pump and it’ll idle around 500rpm. Starts strong with no problems, probably only half a crank every time.

Now the problem. When I’ve driven it recently, it’ll idle high, 1500 to 2000rpm. When in gear, I don’t even have it give it gas at times. Push the clutch in and the RPMs keep revving in the 1500-2000rpm range. Also, it doesn’t do this all the time, just most of the time. I’ve sat parked a few times and I’ll hit the gas real quickly and sometimes it’ll rev down a bit, but not to normal idle. I’ll hit the gas again and it’ll come down some more, sometimes back to normal.

I don’t know carbs but am will to dig into to it a bit and learn a little. Just looking for some help on where to start or what I should be looking at. Thanks.

 

Played around with it when I got to work early. Seems whatever returns the throttle is gummed up or has loosened up. Video of the symptoms. Slowly throttling up and it won’t come back down. Quickly hitting the gas brings the idle back down a bit. Video also shows replicating it under the hood. Now to fix it. Just give the linkage a good carb cleaner spray down?

 

You do have electric choke, it's what the single wire in the latter part of the video is going to. I don't think it's a choke issue though, seems like your throttle isn't closing all the way unless you let it snap closed.
Take the air cleaner off and look at what it's doing. From cold engine condition, pump gas and start, top butterfly/choke should be mostly closed. After time to warm a push of the gas should open the choke plate.
My guess on the return to idle problem is either the throttle plates are binding due to crud in the barrels or possibly the bearings for the throttle plate rod are going out so they stick. Could be something else though.
Having the air cleaner off and looking inside carb can really help figuring out why it's binding up.

 

Thanks. I'll take a closer look at things. Seems like it's going to be a pretty simple fix. About the electric choke, maybe it doen't work. I do the one gas pump when cold and it fires right up and idles right around 1100rpm. The reason I question there being a choke is because unless I pump the gas a second time, it'll idle all day long at 1100rpm. It hasn't ever sensed or timed to a warm engine and slowed the idle. Now that I'm thinking about it, maybe I have the wrong idea about this. Does the choke only effect air/fuel mixture and not idle? I guess I've been thinking the choke would also idle down the engine when warm.

 

The choke are the plates on top, the throttle plates are the ones in the bottom picture.
The choke functions by closing (mostly) when the gas is pumped before the electric coil warms up. By restricting airflow it causes the engine to draw more gas from the carb while choke is engaged. When warmed up (the electric coil) the choke plate will stay open after the gas is pushed decently. That should drop idle to where it should be, like 700rpm ish vs 1100-1200 or so while choke is engaged.

Your problem could be that the choke wants to stay closed, but it think it's more likely that the throttle plates aren't returning all the way back to closed/idle position.
Check that the wire going to the electric choke is 12v+ only when the ignition is in run position and off when key off.