Running Rich

[YukonJack]

I have a 47 Plymouth that runs rich. I get a strong fuel smell from the exhaust when it runs and a puff of smoke on acceleration. The car stumbles on acceleration unless the choke is partially closed. My timing is set at TDC, I have 18 1/2" vacuum at idle and run an electric fuel pump. My first thought was a vacuum leak, but I wouldn't think my vacuum would be 18+ with a vacuum leak. I was running a 180 thermostat but the car was running at 190-195, thought that was a little hot. It now has a 160 stat and temp stays about 170. Seemed to run better with the 180 stat, but it still wasn't right. Any help on this will be appreciated.

[Lou Earle]

Might not be the problem but all those symptoms are indicating timing is off. I would advance it a bit and see what happens. I simply loosen the holding screw and rotate the dist some. It sounds to me like late timing - i would move it clockwise a tad

Lou

[Normspeed]

Running that rich could mean it's time to freshen up the carb with a good rebuild, including an inspection of the float to see if it may have fuel inside it due to a leak.

Usually adding choke would make it run even richer. Are your plugs sooty? Besides the timing you might check the vac advance for leaks too. Easy to check.

Oh, also, I see you run an electric pump. Maybe too much fuel pressure, overriding the float needle? Just throwing some ideas out here...

[claybill]

all of the above..i thnk it is the carb adjustments.

first, check your plugs. very probably the float level is high or gas leaking past the float....

bill

[steveplym]

I had the same problems last year with my '47. Would miss on deaccleration and run very rich at times. Had Wyoming carb rebuild the carb and have not had any problems since. I replaced the points, condenser, vac advance, and plugs before finally breaking down and rebuilding the carb. Runs real good now.

[YukonJack]

I noticed the base plate of my carb is cold and wet ( condensation, not fuel ). Could this be causing my problem? What would cause this?

[Don Coatney]

  YukonJack said:

I noticed the base plate of my carb is cold and wet ( condensation, not fuel ). Could this be causing my problem? What would cause this?

Jack;

Cold carburetor base indicates your heat riser is not working. Does your engine run rich after a 20 mile drive or just after a trip around the block?