Recently one of my engines had a busted choke cut-off, replaced that but then the engine was running poor while it was cold. I then replaced all the spark plugs (which the old ones almost had nothing left of them) engine ran much better, but still has some troubles when cold. I noticed when the engine is cold, that there is fuel pouring out of the fuel return line from the carburetor and the other engine has no signs of fuel return. Also, I took of the filter and looked into the carburetors on both engines. On the engine running fine I could barely see fuel injecting into it, but on the engine that is running poorly I see lots of fuel. Any ideas…
Hi, Gas Engines with Carbs, it's like stepping back in time!!!! Maybe the float in the poor runner has sunk and the fuel pump is just flooding the engine all the time of the needle valve that the float controls is damaged/stuck open.
You could switch carbs between the 2 engines and see what happens. If the problem follows the carb, get that one rebuilt.
Good idea is to throw them away and buy Holleys, much simplier and easier to work on. I had Crusaders with Rochester Quadrajets on a boat years ago and finally listen to a friend and replaced them after trying rebuilds and numerous "mechanics" who swore they could adjust and set them. Go to the Holleys.