Reply To: Problems with my 75’ 25 Johnson

[JACQUES]

I tried 3-4 of them last summer and was going nuts till I found oud I had misaligned the pump’s rear vacum port with the modified side cover drilled hole to get vacum pulses on my converted QD.

It is very unlikely you had 2 bad pump but sh… does happen

I would try to first run that engine with a small supply of fuel fed directly. into the carb. .. it all goes well you can start backtracking to fix the pump

fuel pumping requires vacum pulses from the crankcase to flex the pump diaphragm .

if you remove the pump and sparkplug and spin the FW with a drill can you feel pumping action in the motor’S vacum hole where the pump mounts ???

if you don’t……. I suspect that engine will not even run properly in the above “manual” fuel test because it won’t pull in the fuel either from the carb .

if you do feel good pumping yes then concentrate on the pump not doing its work to feed the carb properly

aside from my mindless alignment issue last summer I never really had any issues with these small pumps and I use mostly chinese versions

keep at it… patience brings joy !

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