1982 782 runnung rough at idle

[MikeBrindle]

Hi all,
So my wonderfu 40 year old 782 started running rough at idle and I noticed a small whiff of smoke under the dash on startup. Where is the best pace to begin my search for wellness in my old friend?

 

[jkoenig]

For mine, it was the fuel tank. Peek in the cap. Is there debris in the tank? Take the fuel line off of the carb, and verify good flow out of the fuel hose. If not, replace the shut off, hose and grommet (roughly $20). Flush the tank while you have the shut off out. Then move on to a carburetor kit, and plugs.

What color was the smoke?

 

[1811Cub]

Smoke, as in exhaust produced or electrical fire related?

 

[wh cc guy]

I think just for starters I would replace the spark plugs.

 

[snicklas]

If it is smoke from under the dash, that sounds electrical (I don’t think the crankcase breather is on the flywheel end of those engines) I would disconnect the battery until you found where it came from. Otherwise it may “fix” itself….. and what ever structure it is sitting in…

Since we are thinking the under dash smoke may be electrical in nature, I would drain and pull the fuel tank and take a look at all the wiring back there. Check the switches…. Especially the key switch, they can cause all kinds of funny issues….. Once you have a good look, before buttoning it back up, I would reconnect the battery and crank the engine over like you are trying to start it and see if you see any smoke. You are dealing with 40 year old wiring and never know what might have happened, or chewed on something under there…

 

[PACub100]

If it is smoke from under the dash, that sounds electrical (I don’t think the crankcase breather is on the flywheel end of those engines) I would disconnect the battery until you found where it came from. Otherwise it may “fix” itself….. and what ever structure it is sitting in…

Since we are thinking the under dash smoke may be electrical in nature, I would drain and pull the fuel tank and take a look at all the wiring back there. Check the switches…. Especially the key switch, they can cause all kinds of funny issues….. Once you have a good look, before buttoning it back up, I would reconnect the battery and crank the engine over like you are trying to start it and see if you see any smoke. You are dealing with 40 year old wiring and never know what might have happened, or chewed on something under there…

 

[RAllison]

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