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Johnson 2hp seahorse

T

The PlantGuy

New member
I picked up a 1975 Johnson 2hp seahorse from ebay a few weeks ago and it seems to run pretty well. on the ebay ad, the man mentioned that the water pump impeller should be replaced. how would I know how well the pump is functioning?. When i start it up in the garage, I can see it spitting out water from the lower unit, more water a higher speed, mainly just air at lower speed....Not sure what's involved with changing the impeller if i need to but would rather not tinker with it if i don't have to as my success with small motor repair is not stellar..

I can post a youtube video later if that helps ....thanks!...
 
The motor does not shut itself down safely should it overheat.---------Very easy to change the impeller.-------2 bolts and the lower unit is off.----The pump sits on top of the lower unit with 2 screws.------------On reassembly a bit of grease on the driveshaft spline and make sure water tube goes into pump discharge .
 
kimcrwbr1 said:
Yea there dont seem to be anything wrong with the impeller but what happens on those pumps is the housing gets worn and the pump loses pressure. There is a upgrade kit that works great otherwise you need to replace the gearbox.
http://www.marineengine.com/newparts/part_details.php?pnum=OMC0763736
It is kind of tricky to install. Those grooves on the bottom of the impeller housing could be your problem or there is blockage in the cooling circuits in the motor? You should allways see water coming out the exhaust relief holes on the exhaust housing.
Click to expand...

I'm not sure there is anything wrong...i was just planning to replace it based on what the previous owner said, not sure why he recommended it maybe just for maintenance....i do see water coming out of the exhaust, more at higher speeds and just spits at lower speeds....how can i tell if the pump is functioning properly?
 
When vanes take a " set " then the pump does not work very well.--The rubber only last so long.--------If you replace the impeller you will not have to worry for a while.
 
A perfect new impeller on the workbench will at first glance look identical to a almost new but infrequently used impeller that is installed in the lower unit... and has been sitting for some time.

The one that has been in the lower unit will however take a set over time... that is the blades will tend to keep their curved look which decreases its quality (weak). A new impeller will have its blades pointing straight out and flex within the excentric impeller housing which results in a top quality pump pressure.

Change it if for no more than peace of mind... it's too easy to pass up.
 
I would definitely install a water pump "retrofit kit".
I struggled for months with an overheating Evinrude Mate 2HP (basically the same thing as your engine).
The kit has a stainless bowl, stainless plate, different impeller and plastic pump cover.
It solved the overheating problem for good!
 
ok, i swapped out the impeller and it seesm to work fine but shortly after doing some testing, I noticed my prop stopped turning, not sure why, i don't recall it hitting anything in the barrell but in any case i after reseating the the lower unit a few times and the same thing happening i took off the prop and saw the plastic all broken up....what do i need to replace to get this running? a whole new prop unit?...thanks.

http://i123.photobucket.com/albums/o291/johnmathieson/output_zpsqckd8nkq.jpg

http://i123.photobucket.com/albums/...0419_12014_edit_1397926937044_zps5slnydxo.jpg
 
just a follow up to this thread, I did replace the impeller and I'm seeing water spray out of the back however at high speeds when I touch the the right side of the motor just under the cowel , its very hot...I'm not sure how hot it supposed to be.....But I'm having trouble getting the motor to idle properly. The first time I took it out i had the needle valves set to the default and after driving around for a while was able to get it to idle nice by adjusting them....I left them as they were the next day and couldnt get it to idle at all...not sure if its still a cooling problem or carb issue..I've ordered a carb kit anyways..Here's video if it helps...let me know what you think I should do..

http://youtu.be/HPV3kYFz47c

thanks!.
 
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