1953 scott atwater

i have a 1953 scott atwater 7.5 twin cylinder it was locked up and i tracked it down to the bottom end as the oil had leaked out and the forward and reverse gears were a bit rusty and loced up. I have since freed it up and cleaned it up and replaced the gasket and now i need to know what weight gear oil i need to use in it i have looked at a couple of sites but have not found an answer also is a 50 to 1 ratio correct for the fuel ? thanks again for all replies

Re: 1953 scott atwater

It does not use gear oil. It uses Outboard Motor Gear Grease, no longer made. Most people use "Lubriplate 105 Motor Assembly Grease", available at NAPA Auto Parts Stores.

I believe that uses 16:1 fuel mix, but I'll look it up to make sure.

EDIT: Yep, 16:1. That's 1/2 pint of oil per gallon of regular unleaded gas.

Re: 1953 scott atwater

There is a simple rule of thumb for determining the required fuel mix ratio:
If the piston pin uses simple bronze bushing, then the mixture ration could be between 1:16 to 1:33, if it has needle bearing then the mixture ratio could be from 1:40 to 1:60.

They started using needle bearings from the sixties, but this varies from manufacturer to manufacturer.

For older engines you see lower mixture ratios, like 1:16 for your engine. Later engines used higher ratios. This was mostly the result of improvements in the two-stroke oils, as well as partly of improvement in metallurgy of the machine components.

So with the newer oils available today you could probably go up to 1:20 to 1:25.

Good luck, Peter

Re: 1953 scott atwater

F_R said:

It does not use gear oil. It uses Outboard Motor Gear Grease, no longer made. Most people use "Lubriplate 105 Motor Assembly Grease", available at NAPA Auto Parts Stores.

I believe that uses 16:1 fuel mix, but I'll look it up to make sure.

EDIT: Yep, 16:1. That's 1/2 pint of oil per gallon of regular unleaded gas.

Click to expand...

Mr Roach,

I would heed FR comments. He has given you excellent advice.


Here is an good article for your reading. There is an excellent tip on how to deal with the sometimes hard to get wico coils or them being very expensive.

http://www.oddjobmotors.com/scottatwater.htm


Here are links to guys who make replacement impellers for your motor.

http://www.chrystine.com/impellers/index.html

http://home.earthlink.net/~flyingscott/


Here is a site that his replacement parts for ignition and carburetors and etc. (Just scroll down to the Scott McCulloch portion.)

http://www.laingsoutboards.com/newp...4, Sears from 1964-69, Corsair, some Haiwatha

They may have parts diagrams or service manuals.

Good luck!!

Re: 1953 scott atwater

You can get a Scott-Atwater service manual 1946-56 from acmeoutboards.com
Good luck, those old Scotts are good runners when all is said and done.

Re: 1953 scott atwater

tmcalavy

Sent you a PM

Re: 1953 scott atwater

Hey David/Cajun,
You need to clean up your PM inbox...tried to reply, but your box is full. Short answer is I gots one already. Where are you at in cajunland?

Re: 1953 scott atwater

I too have a 1953 Scott. Mine likes 20:1 it's a little lighter then 16:1 and it doesn't load up as bad. 16:1 is real SMOKEY.....