The Ford Barn

dgmgohl · 09-08-2018, 03:40 PM

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.

Karl Wolf · 09-08-2018, 04:23 PM

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

40 Deluxe · 09-08-2018, 05:48 PM

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.

51 MERC-CT · 09-08-2018, 06:13 PM

You didn't mention checking the float level.

WABOOM · 09-08-2018, 11:19 PM

Mine did the same thing and all it needed was a coil.

ford38v8 · 09-09-2018, 12:13 AM

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The replacement of needle and seat will almost always require an adjustment of the float level.

dgmgohl · 09-09-2018, 07:19 AM

I have the float set to spec. 7/32

dgmgohl · 09-09-2018, 07:20 AM

Installed new coil before firing it up. Thanks.

09-08-2018, 03:40 PM	#1
dgmgohl Member Join Date: Aug 2018 Posts: 53	Merc 255 issues 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.

09-08-2018, 04:23 PM	#2
Karl Wolf Senior Member Join Date: May 2010 Location: Mill Valley,Ca. Posts: 1,509	Re: Merc 255 issues 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

09-08-2018, 05:48 PM	#3
40 Deluxe Senior Member Join Date: May 2010 Location: now Kuna, Idaho Posts: 3,779	Re: Merc 255 issues 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.

09-08-2018, 06:13 PM	#4
51 MERC-CT Senior Member Join Date: May 2010 Location: East Hartford, Ct Posts: 5,898	Re: Merc 255 issues You didn't mention checking the float level. __________________ DON'T RECALL DOING SOMETHING FOR MYSELF BASED ON SOMEONE ELSE'S LIKES OR DISLIKES

09-08-2018, 11:19 PM	#5
WABOOM Senior Member Join Date: Jun 2018 Location: Minnesota Posts: 347	Re: Merc 255 issues Mine did the same thing and all it needed was a coil.

09-09-2018, 12:13 AM	#6
ford38v8 Senior Member Join Date: Jul 2011 Location: SF Bay Area Posts: 6,641	Re: Merc 255 issues Sponsored Links (Register now to hide all advertisements) The replacement of needle and seat will almost always require an adjustment of the float level. __________________ Alan

09-09-2018, 07:19 AM	#7
dgmgohl Member Join Date: Aug 2018 Posts: 53	Re: Merc 255 issues I have the float set to spec. 7/32

09-09-2018, 07:20 AM	#8
dgmgohl Member Join Date: Aug 2018 Posts: 53	Re: Merc 255 issues Installed new coil before firing it up. Thanks.