40 HP Evinrude needs a new impeller

[buddhapi]

I know the model number of my 1974 40 HP motor is 40455S, but the lower unit is green, and not original. are there any numbers some where on the lower unit that I can look up to find what impeller I'm going to need? what was the last year of the green Johnson motor? how many years and sizes, as far as the lower unit, interchange with this powerhead, etc...sorry so many questions.

 

[F_R]

Re: 40 HP Evinrude needs a new impeller

Depends on the shade of green. You could have a 1955 25hp lower unit on there, or you might have a 33hp from 1967-up. OR, all years had green primer, if it has not been color-coated. No matter, anything they may have put on there will have the same impeller as what belongs on there. But you will have to identify it if you ever have to order internal parts.

40hp motors 1960 through 1970 are different, but those lowers won't fit your 1974, so you don't have one of those.

 

[buddhapi]

Re: 40 HP Evinrude needs a new impeller

so, this could have been an NOS unit installed later in life, and just never painted? it could be the dark green primer? interesting.

 

[F_R]

Re: 40 HP Evinrude needs a new impeller

The zinc chromate primer is a light green and not shiny. If you have a dark green, it probably is a 33hp from 1968-ish.

 

[buddhapi]

Re: 40 HP Evinrude needs a new impeller

so, then I'll need to do more checking to get the correct impeller? otherwise, parts reference tells me my impeller fits 1974-1976 40 HP only. are there casting numbers somewhere on the lower unit to look for?

 

[buddhapi]

Re: 40 HP Evinrude needs a new impeller

could this lower unit come off a Johnson motor? or aren't they interchange-able?

 

[Rick.]

Re: 40 HP Evinrude needs a new impeller

It might have. Again not to worry as the impeller will be the same either way. Johnson and Evinrude are for the most part identical when it comes to parts. The only core difference is the colors and decals. That is a bit of an over generalization but for the most part it's true. Both made by OMC. Best of luck. Rick.

 

[54fleetwin]

Re: 40 HP Evinrude needs a new impeller

you will find a part number on the pump housing

 

[F_R]

Re: 40 HP Evinrude needs a new impeller

OK, I learned something today. I learned that 1974-76 40hp motors use a different water pump than the older motors I was speaking of. I don't know what the difference is, but the part numbers are different. Unless somebody here can enlighten us on those differences, your best bet is to take your old impeller to an Evinrude dealer and match it up with either pre-1974 or post-1974 parts.

I can tell you that pre-1974 motors I suggested use a 378891 impeller, replaced by 775521 (18-3006 here at iboats). 1974 thru 1976 use a 386165 impeller (no iboats equivelent).

I had Johnson in mind when suggesting possible green motors. Yes, Johnson and Evinrude were the same back in those days.

That's all I know.

 

[bktheking]

Re: 40 HP Evinrude needs a new impeller

Upper bearing and driveshaft changed as well, willing to bet the diameter of the shaft increased.

 

[54fleetwin]

Re: 40 HP Evinrude needs a new impeller

you will find a part number on the pump housing

From this number, you should be able to find all the years and models that used this housing, from there, you can get an impeller #