Merc 255 issues

D

dgmgohl

Member
In previous threads, I've followed instructions for the teapot carb and distributor. I have a 1953 Merc 255 in a 52 Ford Mainline. I now have the car running, fires right up, but upon acceleration it bogs down. No back fire, just bogs down. I've replaced the needle and seat, accelerator pump and 2 two idle screws. Baffled.
 
Use a timing light to check the distributor advance while running.
Is the vacuum advance on the dist. OK?
Is the carbureter accelerator pump working...

Karl
 
Have you checked the fuel pump for flow and pressure? A weak pump can give enough fuel for idling but not enough to handle a load. A weak coil gives similar symptoms. It produces enough spark to idle OK, but under load (acceleration) will misfire or bog. The old MOTOR and Chilton Manuals from the '50's have the needed specs and good troubleshooting procedures.
 
The replacement of needle and seat will almost always require an adjustment of the float level.
 
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