johnson 1962 5.5 changing water pump impeller

[OptsyEagle]

Re: johnson 1962 5.5 changing water pump impeller

If you order the water pump repair kit #391391 it comes with the plastic housing and the smaller impeller. It also comes with that gasket and since it profiles the housing perfectly I have to assume it goes between the plate and the housing, like it is in the above picture. I also remember that the housing did not fit absolutely perfectly. If I recall, there was a small obstruction that I fixed by sanding off a little plastic on the outside of one of those holes (maybe 1/16" at most). It gave me the impression that someone at OMC decided that this kit, possibly used on another motor would work better and more cheaply then the original version for the 5.5Hp. They were almost correct. It did require a very, very slight modification. I suspect the person that assembled the one above, did not make this modification. In theory he shouldn't have had to.

To add to this. Once assembled, I could take a shower with the amount of water this assembly pumps out. It really increased the water flow and I have had no problems with it for the last 5 years (the impeller is scheduled for replacement this spring). My guess is that the smaller impellers probably last a little longer as well, but that is just my guess.

 

[HighTrim]

Re: johnson 1962 5.5 changing water pump impeller

Thanks Optsy for that part number, could not find it in my catalogues for some reason.

So the part number 391391 has been superseeded to 0763758, here it is.

Evinrude Johnson OMC 0763758 - Water Pump Kit @ MarineEngine.com

I have never tried a plastic housing. Have never really found a faulty metal housing to tell you the truth. Probably most of my motors still have their original housings. I can see how the smaller pump would create more pressure though.

 

[nwcove]

Re: johnson 1962 5.5 changing water pump impeller

still have reservations about that gasket location??? maybe its right for the retro fit?? maybe it doesnt matter?? maybe ive been putting it under the bearing housing for no reason??

 

[2dogsnight]

Re: johnson 1962 5.5 changing water pump impeller

Gasket was between housing and impeller plate....you can see shiny spot where impelled was turning on plate

 

[2dogsnight]

Re: johnson 1962 5.5 changing water pump impeller

here is view whats under impeller plate.......

 

[2dogsnight]

Re: johnson 1962 5.5 changing water pump impeller

water pump impeller installed....tried the motor in the barrel....runs good.....pump is working......BUT...after running it fir 3-5 minutes, noticed what seems to be some sort of oil in the water....looks like gear oil from gear box....wandering what needs to be done - for sure some sort of O-rings in the gearbox.....

 

[OptsyEagle]

Re: johnson 1962 5.5 changing water pump impeller

Whenever you run a 2 stroke outboard in a barrel you are going to have some sort of mess. Remember that a 2 stroke motor does not burn all of its fuel as well as a 4 stroke does (some gas/oil mix gets shot right out the exhaust before burning, during the power stroke). 2strokes burn the fuel even worse when idled in a barrel as opposed to having a load put on them. That is just part of the technology.

Now that exhausted mess all gets shot out under the water from the motor's exhaust system. Lastly, oil floats so it will all accumulate on top of your water for you to see.

So, I cannot say whether your lower unit is leaking or not, but I can say that the last time I ran my 5.5Hp motor in a barrel, I had quite a mess as well.

If you want to be sure about the integrity of your lower unit, then let the motor sit for a couple of days and remove the lower drain plug and see if any water comes out. Any water that may have gotten in there will eventually make it to the bottom of the lower unit (why you should wait a couple of days since the gears mix it up quite well when it has run) so all you need to do is see what the first drip of substance is ... oil or water. Do it quick and you can set your mind at ease. I think what is in your barrel is exhaust crud but that is only because you are definitely going to have exhaust crud there, no matter what.

 

[kfa4303]

Re: johnson 1962 5.5 changing water pump impeller

HI 2dog. Don't worry about the yucky water, that's perfectly normal when running a 2-stroke in a test tank. It won't be nearly as bad on the open water. However, it never hurts to check/change the gear oil. Just be sure to replace the washers on the DRAIN/VENT screws when you're done as they are a one time use item.

 

[2dogsnight]

Re: johnson 1962 5.5 changing water pump impeller

Optsy and kfa,

thank you very much for your responses....it cleared all the worries I had about my motor, I will check everything per your recommendations.
One last thing I have is the position of the pump itself - does it have to be under the water or can it be just an inch or so abouve the water level while mounted on the boat????
Bought a short shaft according to measurement recommendations, but didn't take position of the water pump into cinsideration - and the fact that is not a self primed