1952 Fleetwin 7.5 hp

[dblackb99]

I have done a lot of work to this engine to get it running - new coils, new plugs, new points, carb kit.

I now have it running but it runs fine for only a few minutes then knocks, clunks, and quits. It starts up again right away and then is okay for a few minutes (anywhere from 30 seconds to 2 or 3 minutes) before it quits again. I have adjusted the low and high speed settings on the carb per specifications, and points settings are also per spec. Any suggestions/ideas?

Thanks.

 

[AEROCOOK]

When it dies, is there still fuel in the bowl? You didn't mention water pump in your list of repairs, has it been done? If not, is it possibly overheating?

 

[F_R]

Educated guess: Fuel filter in gas tank is partially clogged. It isn't flowing enough gas fast enough to keep up with what is being consumed. Dang near impossible to clean, they are meant to be replaced. Part number 276883. Personally, I unsolder it out of the fitting and solder in a roll of brass filter screen.

Another possibility is wrong float valve. Those things come with different size holes and if too small, same as above---can't keep up with the use. That part number is 276914

 

[dblackb99]

Aerocook - I did replace the impeller and there seems to be lots of water flow, so I don't think overheating is the issue.
F_R - I suspect a fuel issue as well. I replaced the in-tank filter (clogged) with an in-line filter in the hose. I can't imagine it's restrictive enough to cause problems but I could simply bypass it for a short test. If so, where does one get brass filter screen?

 

[F_R]

I got mine from McMaster.com 80 x 80 x .0055" Comes in a square foot sheet, enough to last you a lifetime plus supply all your friends.

 

[Vintage Boat Guy]

I had the same problem with my 1954 Evinrude 15hp, it turned out the fuel bowl fuel entry was clogged with crud. After cleaning it out it ran like a champ.