evinrude 4hp 1984

Hi All

Just joined after a referral from another site Have a question I wonder if you can help me with.

I am in the process refurbing my little evinrude 4 1984 and have run into a problem putting the impellor on the drive shaft, I can not
for the life of me figure out what makes it turn!

I have a notch in the impellor and a flat spot on the drive shaft, but the
two do not seem to augment each other in any way and the impellor can just
spin.

I am sure i am missing something obvious here.....

I wonder if you guys have any advice as I dont want to fiddle with the clutch,
and coolant pipe just to find the impellor does not turn

At the moment if I put it all together the driveshaft seems to just spin
inside the pump housing not 'catching; the impellor.

I hope you understand the question and this isnt all gibberish as a result
of working too much and not remembering something obvious! I should have kept in one piece until it came to putting it back together

Thank you

Mark

Re: evinrude 4 1984

You are missing the drive pin for the impeller, look around on the floor. You should have gotten a new one in the pump kit.

Re: evinrude 4 1984

As above. # 17 in THIS DIAGRAM

Original ones are a round steel pin but I have come across others which are plastic and a flattish triangular crossection. The notch in the impeller for them is a slightly different shape.

Re: evinrude 4 1984

Thank you both very much!

I am currently trying to manufacture one from an allen key .... king of the cheapskates!

Those things are pretty hard though.

I have one that is a great fit and one that is a bit looser, am guessing the tight fit is prefereable?

Thank you for the useful info.

Mark

Re: evinrude 4 1984

Snug fit essential I would think.

It is apparently the same part as in my 6 hp and that mics up at 0.125" ( 1/8") diameter and is 25/64" long.

An Allen key seems an odd choice of starting material.
I thought it might be stainless steel but it's magnetic so apparently not, at least not an austenitic steel. I think despite that if I was making one I'd start from a stainless steel bolt.

Re: evinrude 4 1984

went for the allen key as it has flat edges that fall into place in the shaft and the impellor.

I have now revised this plan by using part of a pen lid from a biro (plastic, flat edges and snug fit) which seems to hold very well and once the impellor is in the pump housing can not move anywhere!

Mark