1954 johnson CD-11 5.5 horse power running issues

[Wolfs_hell]

Throwing this out there as i'm not sure what to do. I have a 1954 johnson 5.5 hp. I replaced the water pump, coils, points, and condensers. Rebuilt and cleaned the carb, and converted it to a fuel pump. It starts by the third pull, and runs wonderfully smooth until it heats up. Then it bogs down, shudders, revs back up, bogs down again, etc etc. I have checked over everything i can think of. Anyone with any ideas as to what is wrong?

 

[HighTrim]

Starving for fuel.....what method did you use to add the fuel pump? The intake manifold modification?

 

[racerone]

Clutch in the lower unit binding ?

 

[F_R]

Sintered fuel filter element in bottom of carburetor partially clogged?

 

[kbait]

No Title

When racerone says clutch in lower unit, he doesn't mean clutch dog, he means shock absorber.. Check pic. It's directly underneath bearing plate and connects to pinion gear in lower unit. If spring breaks, it'll cause binding, and perhaps your issue. If you pull the spark plugs on your motor and pull it over, it should spin freely..any binding is likely broken shock absorber spring. Good luck!

 

[Wolfs_hell]

I dont think its starving for fuel as the glass bowl remains full, and i cleaned the filter when i rebuilt the carb. The fuel pump conversion i did was the vacuum cap one, where you remove the check valves and plug one hole. I will check for this though to make sure.
As for the shock absorber, would that have an affect when the engine is in neutral and running? The last time i ran it i left it in nuetral and it still started acting up once hot.

 

[racerone]

Does spark jump a gap of 1/4" or more, yes or no ?

 

[HighTrim]

That doesn't mean that its not starving for fuel. They typically run with the glass bowl fairly empty actually. Don't judge on that or that you cleaned the sintered filter. Sometimes, they cannot be cleaned, they were meant to be disposable. Remove it and try again. Also, try to continually pump the primer bulb, does this keep it running smooth?

 

[Wolfs_hell]

I'll try the pump the fuel primmer bulb, but if it was starved for fuel, why does it only act up when hot?

 

[kbait]

Yes, will bind in neutral as gears are always turning with powerhead.

 

[Wolfs_hell]

Ok, did the primer bulb thing, and it ran better. I then removed the original fuel filter and replaced the vac line i was using for the fuel pump with a slightly larger and stiffer one. This seems to have fixed the problem in the barrel, though i will have to take it to the lake to check under load. Now That i think about it, i will pull the lower and check that shock absorber anyway. Thanks for all your help, if i have more issues youll find me back here again.

 

[oldboat1]

Have you checked to see if it is running hot? If the head gets too hot to touch, it's too hot.

If running in a barrel, need to sink the lower unit deep -- half way up the shaft is a good rule of thumb. Running lean can likewise cause overheating, but water flow (or lack of it) is a more likely cause.

 

[F_R]

You said the glass bowl was full. That is a sign that the filter was clogged. Those bowls normally run empty or nearly so. Don't try to understand it. Capillary action or something. But if you removed the filter and now it runs, you settled the question.