1964 Johnson Seahorse 5 1/2 Running Poorly

[AJ168]

The engine will seem to run fine, then the rpm's will decrease, and then go back up. After the engine is warm, it's very hard to restart. At first I thought that it was the carb float but that looked fine when I had it apart. The fuel pump seems to be pumping fine and all of the fuel lines are clear and have been recently replaced so it's unlikely that there are any leaks. When pumping the ball, the engine chokes. I have no idea what could be wrong.

 

[JB]

Re: 1964 Johnson Seahorse 5 1/2 Running Poorly

Surging is often a symptom of water in the fuel, air leak in the fuel supply or loose debris intermittently restricting the fuel uptake in the tank.<br /><br />Good luck.

 

[Paul Moir]

Re: 1964 Johnson Seahorse 5 1/2 Running Poorly

When pumping the ball, the engine chokes

That would indicate to me that either the fuel pump is leaking or the needle and seat in the carb is leaking (due to trash in the fuel or wear). It's easy to check the fuel pump - just detach it from the engine and pump up the primer bulb. If gas comes out the back it's bad.<br /><br />Carburetor repair is accomplished by picking up a kit and rebuilding the carb. Which is not very difficult.<br /><br />One last possiblility is you have an air-leak in the fuel supply (causing lean running), and have compensated for it by adjusting the carb rich. Pumping the primer temporarily corrects the air-leak and so the engine runs rich.

 

[AJ168]

Re: 1964 Johnson Seahorse 5 1/2 Running Poorly

It's not really surging, it'll run fine for a while then go down then increase again. It's not like something's getting clogged in the fuel system. Plus I'd just cleaned out the carb that day and have two filters running into the carb. Both are spotless. And they don't restrict fuel flow because they've been there for a while.

 

[Paul Moir]

Re: 1964 Johnson Seahorse 5 1/2 Running Poorly

When the carb and fuel pump are working correctly, pumping the primer bulb will not affect how the engine runs.