1957 Johnson Seahorse 7.5 AD-11 won't run!

[Medicman613]

Hey all,

I have picked up a 1957 johnson seahorse 7.5 AD-11 but can't seem to get it running! I have replaced the spark plugs with the proper plugs, I am getting spark, I have visualized the coils x2? which seem to be intact. Both spark plug wires are in correct place. I am getting good pressure in the gas tank. Carbeurator is clean. Hi /low adjusted. Ever you 10 pulls or so the motor backfires.

Any suggestions for next steps?

 

[racerone]

Spark on plugs laying on the block means nothing to us here.---Does spark jump a gap of 1/4" or more with a snap you can hear ?----Yes or no ?----Also do a compression test.

 

[Crosbyman]

gas in the bowl ok ?
tried squirting some gas in the 2 cyl to help it along
move the throttle beyond START a bit
fresh gas ?
carb looks clean or was cleaned properly ???
you need air fuel and sparks to work ....is the air silencer cleaned out or rented out to a bug family
choke plate working ok ?

nice engines... get it gooing !!

 

[pro-crastinator]

FUEL. Pull plugs, squirt in gas - clean and fresh gas/oil - 16:1 - just enough, replace plugs and wires. Give her a tug. Report back with results.
Depending on what happens here, there may be more to do.

IGNITION. Spark test. A real spark test.

COMPRESSION Check it with a compression gauge. If it "feels right" when you pull the cord, you can move (this step) the compression step to 3rd on your list.
If it pulls easy easy, you might do the compression check first.

All this is easier than it looks. Best o luck.
-Bennett

 

[Medicman613]

After much stressful work it was an easy fix. Turns out the sparkplug wires were backwards coming out from under the flywheel leading me to believe they went on a certain way... after much pulling the starter pawl broke... (new one on order). No water seems to be cooling the engine now. i have pulled the power head, dropped the lower end, and taken out the impeller which is in good shape. Seems like there is a lot of muddy build up and silk in the motor possibly preventing the impeller from spinning. I have ordered a new one and will begin a big engine clean before my parts arrive. The end is in sight! Or maybe I just jinxed it.

Curtis.

 

[Crosbyman]

put a tye wrap on the top plug wire ...or find and old metal clip maked TOP