1966 Evinrude Prop Installation Help

[michaeldodd]

Please excuse any ignorance in boat mechanics or in the us of this forum. I am a newbie.

I have a 1966 80HP Evinrude outboard with a Selectric (ie push button) throttle. I am having a problem related to the prop. The attached photo hopefully shows the issue. If I place the prop what appears to be all the way in, the shear pin won't line up. If I line up the shear pin, the space/gap between the prop and the rest on the engine seems too large.

Any help is greatly appreciated.

 

[steelespike]

Re: 1966 Evinrude Prop Installation Help

My first thought is the prop is not intended for that motor What is the diameter and pitch.usually near the base of the blades.
Possibly on the under side.
You can measure the diameter from the center of the bore to the tip of a blade and double it.
While the gap isn't right being a non thru hub exhaust the fit isn't as important.
Some good clear pics on the motor may help.

 

[michaeldodd]

Re: 1966 Evinrude Prop Installation Help

Thanks for the reply Supreme Mariner. The prop is 10.25 diameter and I think a 10 or 11 pitch. This is what is spec-ed in the owners manual. I am relatively certain that it is the right prop. When I had it on the water last time, the reverse worked fine but the forward was either slow or non-existent. I thought it might be a spun prop, but a friend looked at the prop and didn't think it was spun. I will attach some more photos. Not sure what would be helpful, so let me know if specific photos are needed. Thanks again!

 

[steelespike]

Re: 1966 Evinrude Prop Installation Help

A spun hub is easy to check.Just draw a water proof line across the hub onto the body of the prop.
Do a test run and check the line.If its broken its spun.
These motors have a odd gear ratio about 1.15 : 1 almost direct drive.
The 10 or 11" pitch is about the smallest pitch available intended for a heavy or hard to push boat.

 

[michaeldodd]

Re: 1966 Evinrude Prop Installation Help

It is on a Sylvin 19" Deck boat so it is quite a bit of boat to push. I can double check the "spun" issue. However, I have two props and both leave the gap I discussed (first photo of last post). Could part of the "drive shaft" got over extended some how? Thanks again, I appreciate you time and insight.

 

[steelespike]

Re: 1966 Evinrude Prop Installation Help

Unfortunately I don't know much about the electric gear case.
In my opinion if the prop shaft has moved its because something has failed or is failing.
Is there end play or side play in the prop shaft.There may be a little normal end play.
To address your possible slipping A poor connection to the coil may cause slipping of the clutch.
The blue wire is reverse and the green wire is forward.
You need a fully charged good battery and a proper charging system.You should have a reprint factory service manual for any trouble shooting .I believe available here at iboats. Resistance on the clutch coils should be 8 ohms.The electric shift parts are hard to find and expensive.
Ignition parts are hard to find and expensive.

 

[jimmbo]

Re: 1966 Evinrude Prop Installation Help

The gap in the 1st posting looks larger than the gap in the later posting. Perhaps the black prop has slipped basckwards an 1/8 inch on the hub. Post a picture of the fist prop showing the same view as the first pic of the second prop. There is supposed to be a washer/spacer located between the prop and the drive pin to keep the drive from being jammed against the prop if it should shift.

 

[michaeldodd]

Re: 1966 Evinrude Prop Installation Help

Thanks for your assistance Jimmbo. It is greatly appreciated. Attached are additional photos. The space looks roughly the same. Is the washer/spacer you speak of part of the prop itself or a separate item. If a separate item, then it is missing. Sorry for being a little clueless. Any additional insight will be greatly appreciated.

View attachment 165085