Heavy duty or standard motor?

[iggyw1]

Hi guys,

I recently bought a really nice 1965 outboard, Evinrude 75 Horse Power Speedi-four. Model number is 75553. I need a new prop nut (the plastic nose cone at the end of the prop that the cotter pin goes thru to hold the shearpin in place). Without this prop nut, I would lose the shear pin and prop!

I looked up the part number, and it has two different numbers for this prop nut. One is for a heavy duty gearbox set up., and one is for the standard gearbox. How can I tell if I have a heavy duty or standard gearbox? The way I understand it is the model number can be either one. I'm confused on what prop nut to order????
Thanks for your help!

 

[hardwater fisherman]

Re: Heavy duty or standard motor?

go on a website where you can see the parts blowup of your motor. you will see the two gearcases are shaped differently. on the heavy duty one the extreme lower portion with the skeg is a split version.

 

[racerone]

Re: Heavy duty or standard motor?

There was a special low pitch prop as well.----This prop was a small hub and a smaller plastic cap.----The standard prop had a bigger cap.------Picture of prop or numbers from prop will be helpful here !

 

[F_R]

Re: Heavy duty or standard motor?

Model 75553 is a Standard gearcase
Model 75335 is a Heavy Duty gearcase

There were two styles of nuts for the standard gearcases (actually three)

Part number 380610 nut and 307244 Cotter pin
Part number 377924 nut and 311766 retainer clip

In addition, there was a smaller nut used on a small hub prop. I gotta run for right now, and don't have time to look it up. The nuts I listed fit the larger hub prop, hub is same diameter as the gearcase. The small hub prop hub is considerably smaller than the gearcase diameter and looks like a misfit. If that is what you have, I'll get back with you later.

See you after Church

 

[Chris1956]

Re: Heavy duty or standard motor?

Weren't the heavy duty gearcases the mechanical shift ones (versus elec shift)?

 

[F_R]

Re: Heavy duty or standard motor?

Not exactly. The Selectric shift Starflite ones were a different model
75582 (Blue)
75592 (Grey)

The op's motor, 75553 is a "Standard", with mechanical shift. The 75335 Heavy Duty is also mechanical shift. The Heavy Duty gearcase actually is a resurrecton on the old 1958-59 50hp lovingly known as the "Fat Fifty", installed on a 75hp upper..

 

[iggyw1]

Re: Heavy duty or standard motor?

Thanks to all that responded to my question. I have a new replacement retainer 'nut' for my motor. I went to a repair shop instead of ordering it on line so I was certain it was the same one. It was about a 45 minute ride each way, but I wanted to make sure. I have it now and I am all set. Thanks again!
IGGY