1955 Johnson 5.5hp impeller issue

Bought it last year, ran fine. Was spitting out water perfectly, then while running down the lake, it shut off. After a few minutes, I restarted, to notice it wasnt spitting out any more water. I assume it shut off due to overheating (as evidence of the hot marks on the engine (what im thinking is a valve cover area). )

Impeller is in perfect shape. I can not find ANY obstructions in the tubes or pickup. I pulled the powerhead, and connected the driveshaft to a drill (keeping the prop area in the barrel of water), and can not get water to come up.

I looked around this site, and count not find a solution. I have torn this down a few times to no avail. The impeller turns with the driveshaft as it should. Gasket below metal plate in the impeller area is good.

Any thoughts?

Thank you

Re: 1955 Johnson 5.5hp impeller issue

THe only thing I can think of is that the impeller hub is spun, or the impeller key is sheared. If the intake is clear, and the water tube gaskets are good...... Do you have the lower unit totally submerged when running your drill? the water level has to be above the pump housing since the pump is not self-priming.
Last of all, if you get the lower unit to pumping water on the drill but still have no water exiting the exhaust ports, you may have a water tube that has a hole in it due to rubbing on the driveshaft if the alignment is wrong.
---all I can think of,
JBJ

Re: 1955 Johnson 5.5hp impeller issue

It certainly should have pumped with the drill, but that really doesn't mean a whole lot if it did. I'm suspecting you didn't have it deep enough in the water. Those pumps are not good at pumping air and need to be submerged for priming.

Next you may ask why wouldnt it mean much? Because when running in its normal environment, there is exhaust around the outside of the pump. If exhaust gets into the pump, it destroys the prime. A worn pump housing is one way it gets in there. Along the same track of thought, there is a small angled hole drilled from the pump outlet area to the cup around the drive shaft. The purpose of the hole is to keep the cup filled with water, preventing exhaust from entering through the drive shaft hole. Lastly, make sure the stainless steel plate is sealed to the bearing housing. Have it be clean and use some gasket sealer. Don['t worry about the pump housing to stainless plate, just have it be clean.

One other lastly, look up in the water tube a few inches above the pump. Is there a restrictor in there? Those buggers sometimes get blocked with trash.