johnson 1.5 hp impeller

[ke4rocket]

I just got a 1.5 hp at a garage sale the other day and after a little tinkering got her running very nicely. Now, for my problem. I can't get the lower end to separate so I can change the water pump impeller. It only comes out so far. The manual shows no bolts or keys that locks it into place. Are these just a pain to remove? how much force should I have to use to get it apart?<br /> Any and all comments are welcomed.

 

[JB]

Re: johnson 1.5 hp impeller

Model number?

 

[ke4rocket]

Re: johnson 1.5 hp impeller

OOPS!!!! Sorry! The model is 1R70R and the serial # is E3175095

 

[Paul Moir]

Re: johnson 1.5 hp impeller

It should come right off. Sounds like the splines in the driveshaft are corroded into the crankshaft. If you can, invert the engine and spray the driveshaft (general area, perhaps through the exhaust) with penetrating oil so it drips down to the driveshaft splines. Then drive wedges between the lower unit and the midsection to force the driveshaft out.<br />I'm not sure about the 1.5hp, but with the larger OMC outboards of that era the worst that would happen if the driveshaft was really stuck and you forced it is the impeller key would punch a hole in the impeller housing. Which is a relatively inexpensive part.

 

[ke4rocket]

Re: johnson 1.5 hp impeller

Thanks Paul, I will give that a try.