1955 Evinrude 7.5 fleetwin

[konaboy]

Hello everyone,
I just aquired my first outboard motor, it is a 1955 Evinrude 7.5 Fleetwin. The previous owner told me he hasn't run it in 2 years. I got it home and tank tested it and it fired right up and ran for about 5 mins, I didn't want to run it too long. It pumps good water and shifts nicley. I have read a bunch of posts about this motor and have this much figured out.
First, I need a service manual. Which I am in the process of getting a cd manual from ebay.
Second, I am safe to run it at 25:1 oil mixture as long as I use premium TCW-3.
Third, I should replace the impeller as soon as possible.

A few questions I have right now are: I went to the marina and got a few shear pins I told the guy what year and model engine I had and he gave me some steel pins. With an aluminum prop I was expecting something made from bronze. He told me they haven't made them from bronze in years. My question is can I safely use a steel shear pin on this motor.

I also removed the propeller to remove all the old fishing line and noticed that the line had become fused to some sort of plastic washer.

http://www.crowleymarine.com/brp_parts/diagrams/32483.cfm

The part in question is number 50 on the above diagram, which says it is an o ring. I know what an o ring looks like and this thing looks more like a washer than an O ring. My question is what does this thing do? It is between the oil seal and the propeller so I don't think it is sealing anything. Is it just to protect the oil seal from weeds and fishing line or does it actually seal something?

Thanks!

 

[mchin]

Re: 1955 Evinrude 7.5 fleetwin

Congrats on the nice motor, they great motors and easy to work on. Go to AOMCI.org, it's a club for people who love antique outboard motors.

You may have to replace the coils even though you are getting spark, if they are the original coils, they may fail soon.

Oil mixture i believe was 24:1

Check the lower unit lube, if it's milky or smelly, you may have a leak. the fishing line and plastic washer, which i too believe is fishing line melted together, may have compromised the prop shaft bushing.

I believe the "O" ring you asked about is the "O" ring that goes around the lower unit "Head Bearing" (#48). But I may be wrong. Do you see the "O" ring when you take the prop off?

 

[R.Johnson]

Re: 1955 Evinrude 7.5 fleetwin

Mchin has it right, the o-ring 50 goes around the bearing head 48. If you look closely at 48, you will see a groove in the center, this is where the o-ring goes. If there was a lot of fish line behind the prop, you will probably have to replace the seal in part 48.

 

[jbjennings]

Re: 1955 Evinrude 7.5 fleetwin

Not trying to start a big oil war, here, but your motor should say that the proper oil ratio is 16:1, not 24:1. I believe you'd be fine at 24:1 with TCWIII oil, but myself, I go ahead and use 16:1 in my '55 7.5 and just use synthetic biodegradable stuff.
Just thought that the factory recommendation might be noteworthy,
JBJ​

 

[F_R]

Re: 1955 Evinrude 7.5 fleetwin

Shear pins are supposed to be stainless steel and they are not shear pins, they are drive pins. There is a slip clutch inside the lower unit to protect stuff if you hit a rock, so the drive pin doesn't have to break for protection.

The plastic washer is fish line that has melted from friction. Pull all that junk out of there. And hope it hasn't wrecked the seal.

Originally, the mix was 16:1, one quart of 30wt non-detergent oil to 4 gallons of gas. You can get away with 24:1, but no less. Some people will even dispute that and say 16:1--period. That motor needs it's oil. Yes, it will smoke.

 

[konaboy]

Re: 1955 Evinrude 7.5 fleetwin

Thanks everyone for the info. I wish i would have posted this a few days ago and I would have saved $20. Now i have a fist full of drive pins and an oil seal that seems to be fine. I say seems to be fine because it doesn't leak any oil when sitting on the stand and the oil does not appear cloudy. However, I will definately change it this fall.

The plastic washer is definately fishing line. I couldn't believe it made a perfect impression of the oil seal , but it all makes sense now.

 

[lindy46]

Re: 1955 Evinrude 7.5 fleetwin

I say seems to be fine because it doesn't leak any oil when sitting on the stand and the oil does not appear cloudy. However, I will definately change it this fall.

How can you tell the oil is not cloudy without draining it? Go ahead and completely drain and refill the lower unit before you use the motor.

 

[mchin]

Re: 1955 Evinrude 7.5 fleetwin

JB, thanks for the proper ratio, you're right 16:1 it is. These oldies need to be run right.

 

[foxracin09]

Re: 1955 Evinrude 7.5 fleetwin

hello everyone im new to this as u can see and i been reading and reading and reading lol i just acquird my very first vintage motor it is a 1954 evinrude
fleetwin aquasonic 7.5 i have not yet got to hear it run because i didnt get a fuel tank with it so i found one on ebay and im just waiting on it but while im doing this i would like to learn as much as i can about this motor before i try to start it the only thing i have done to it was replaced the plugs with a ngk i would like to know i have saw in the above post that the ratio is 24:1 and
16:1 can some one give me a sound mixture and i been readin on something about some oil in the lower end is that a special oil? do i need to drain and replace it before i run or try to run it ??? and is there anyone out there that can just give a greenhorn a little more information on my beautie i dont know much a bout the leaning or riching high speed or low speed needles ither
thanks for all the help

 

[wildartstech]

Re: 1955 Evinrude 7.5 fleetwin

Hello everyone,

Second, I am safe to run it at 25:1 oil mixture as long as I use premium TCW-3.

Thanks!

That's a good question. I have a Evinrude 7.5 fleetwin Aquasonic, on the inside label it indicates to use one half pint (.5 pints) to every gallon of gasoline. That's a 16:1 ratio. I was told the Aquasonic is 1955 as that is the only year they used the term "Aquasonic" not sure if that's verifiable but the gasil ratio is cause it's the original label. Also not sure if a Aquasonic is anything different than what you have but would like to know as well? But before you dump anything in there I'd be sure to default to something safe rather than run it with less oil than it needs cause that's a guaranteed poop stick in the gears.

 

[HighTrim]

Re: 1955 Evinrude 7.5 fleetwin

That's a good question. I have a Evinrude 7.5 fleetwin Aquasonic, on the inside label it indicates to use one half pint (.5 pints) to every gallon of gasoline. That's a 16:1 ratio. I was told the Aquasonic is 1955 as that is the only year they used the term "Aquasonic" not sure if that's verifiable but the gasil ratio is cause it's the original label. Also not sure if a Aquasonic is anything different than what you have but would like to know as well? But before you dump anything in there I'd be sure to default to something safe rather than run it with less oil than it needs cause that's a guaranteed poop stick in the gears.

I hope he has it figured out now, he posted 3 years ago

 

[Speedcat]

Re: 1955 Evinrude 7.5 fleetwin

Just looked in the owners manual and for a Evinrude Fleetwin 7.5 Aquasonic Model 7518-7519 it states mix 1/2 pint oil to each gallon. They also recommend Mobiloil outboard or another outboard oil or a regular SAE 30 grade automotive engine oil. Avoid use of low-priced third grade (ML) oils.
rich

 

[Crosbyman]

Re: 1955 Evinrude 7.5 fleetwin

The parts listing 1955 shows part 302333 "Shear Pin" for that motor.

Is it realy a stainless drive pin ?? In any event would there be any harm is using using a piece of brass brass rod as a shear pin to... drive that propeller just in case?


EDIT: On the 1956 and up version that part# is called a DRIVE PIN ....go figure