Model B backfire

[tiger.1000]

Last year the car was running sweet as a nut. First time start this year. On a light throttle car runs well but as soon as throttle is depressed there is a backfire through the exhaust.


Idles sweetly; points,plugs and condenser appear OK.


Adjusting GAV valve has no effect on the problem. Fresh fuel in the tank.


Any clues ?

 

[DavidG]

Stuck centrifugal advance weights?

 

[tiger.1000]

Thanks David but no. Sacrificed lunch and took the bull by the horns. Stripped the carburettor..... jets properly gummed up. Now runs like a model 18 or better !

 

[petehoovie]

I had a similar problem (rough running) with my '37 and '53 after sitting dormant for a period of time. They ran fine prior to winter storage. I chanced that the fuel system could be the culprit. I poured a 12oz. bottle of Chevron Techron into the tanks of these two cars and the engines smoothed out in very a short period of time....