Carb Rebuilt but still have black smoke-gctid344837

[Guest]

I had the carb rebuilt and still have black smoke at cold start. It seems to run better though. Maybe it's because it's -6 C.Is the normal when it's real cold out?

[BLCarl]

If the smoke goes away after warming up I'ts probably the choke adjustment. If its dripping raw fuel down the venturi when running with the choke held fully open. It might be the float adjustment.

It might help us to know what carb and engine you have.

[Chief_Alen]

http://www.recarbco.com/technical/newtrouble.html

[Guest]

It is a Webber 4 barrel. Is it possible to adjust the choke so it's fuuly open or is that not a good idea.

[BLCarl]

The ones I've worked on have the round choke housing on the right side of the carb. There is a plastic center section with wires attached. It's held together with 3 screws. If you losen the screws you can rotate the plastic housing in the direction that opens the choke. If you turn it a long way the choke will never close .It should cure your overchoking problem.

If you want to adjust the choke to work as it should. With a cold engine and wires disconnected rotate the plastic section untill the choke just closes. That is a good starting point. If the cold engine starts and floods back off the adjustment a notch. If it starts and dies right away (starves for fuel) advance the adjustment a notch. There might also be a vacume diafram with a rod going the choke. The rod can be bent a little so that when the engine fires up it pulls the choke open a small amount to keep it from flooding till the electric coil opens.

If the coil in the plastic housing is burnt out or the electric connection is not working the choke will not open. Then you must either replace the coil or back off the adj so that the choke dosen't close.

[Guest]

Ok thanks Carl I will adjust it. I noticed when I took off the flame arestor that the choke wasn't opened all the way. Maybe thats the problem.

Thanks Steve

[BLCarl]

One more thought Steve

Many chokes close by default. If the choke coil is damaged or your not getting 12V to it with the engine running or its not grounded it will stay closed. Rotating the adjustment so it stays open all the time will keep you running but you might have trouble with cold starts.

It's sometimes possible to install the coil backwards or not in the slots correctly and will cause some grief. Some engines have the choke + wire comming from the alternator or a oil pressure switch so the choke heater coil dosn't start working till the engine starts running. In that case the choke wire will be dead until the engine turns over. An inexpensive test light or volt meter is a essential tool.