1955 Fastwin Aquasonic Help 15 hp

[Anthonyfasttwin]

I just purchased a 1955 fastwin aquasonic #15014 it had been sitting for some time prob 10 years. I changed the spark plugs replaced the fuel lines and she started right up. I took it out on the lake today for the second time running 24 to 1 gas oil mix, good bit of water spitting out the exhaust. Ran pretty good for a little while then it started jerking and running really bad low speed and wide open throttle barley going. The rev would go up and down up and down for a while then die. Also it made different noise tones kind of sounds like a knock then more quiet then back to a knock sound. I drained the lower end and it was milky. I would really like to make this old motor run like a champ I just don?t know where to start, what parts I should get, and what work I need to do to it? I?m at a loss with part numbers, service manuals and know how. This will be my first out board project. Any help would be greatly appreciated. Also I would like to know if these motors are any good if not then I will just let it go and what is the difference between a regular fastwin and an aquasonic fastwin?

 

[1946Zephyr]

Re: 1955 Fastwin Aquasonic Help 15 hp

Well, you found yourself a classic there. Below is a list of things you will need to consider doing, to make that classic fun and reliable.

1. Rebuild Carb
2. Recondition the ignition system entirely, unless the coils have already been replaced. It sounds like the points need to be re-adjusted and lube put on the cam. The heels of the points dried up and worn down so the points stopped opening up to the proper gap.
3. Reseal the lower unit and replace the impeller.

These three things will probably come to about $150 in a worst case scenario, but once they're taken care of, you'll have a nice dependable motor that you won't have to work on for many years.

Aquasonic Fastwin was a name that was given to these motors in 1955, when they were re-designed with the rubber mounts and slightly lower noise features than the previous 15hp models (1953-54) 1954 and prior, they refered to it as the Super Fastwin. The Aquasonic name was dropped in 1956.

So, the bottom line is, if the compression is good (and even on both cylinders) then it'll be worth every dime to tune it up right and get it going good. Since it sat for ten years, it is highly recemended anyway.

 

[Anthonyfasttwin]

Re: 1955 Fastwin Aquasonic Help 15 hp

Awesome Thank you Captain for the help. Im going to check the compression today Hope it is good. I look foward to bringing this gem back to life. Do you know where I can get all my parts from and a shop manual?

 

[1946Zephyr]

Re: 1955 Fastwin Aquasonic Help 15 hp

Well, many here would suggest a factory service manual which you can find at the Ken Cook Company. You can see it here. http://www.outboardbooks.com/index.cfm/manual/15014/

As far as parts go, a lot of things you can probably find here. Anything you can't, try Sea-Way Marine, Engine Blade and Prop, or www.vintageoutboard.com. These three places probably can best serve you, but I would try here first, because iboats would greatly appreciate your business.

 

[Anthonyfasttwin]

Re: 1955 Fastwin Aquasonic Help 15 hp

Well, many here would suggest a factory service manual which you can find at the Ken Cook Company. You can see it here. http://www.outboardbooks.com/index.cfm/manual/15014/

As far as parts go, a lot of things you can probably find here. Anything you can't, try Sea-Way Marine, Engine Blade and Prop, or www.vintageoutboard.com. These three places probably can best serve you, but I would try here first, because iboats would greatly appreciate your business.

Praise the lord I have compression 90 in the top and 110 in the bottom. I didnt know that iboats had parts for this old of a motor.

 

[nwcove]

Re: 1955 Fastwin Aquasonic Help 15 hp

you are almost 20% apart in your compression numbers, but hopefully they will come back to spec once you run it for awhile.

 

[Anthonyfasttwin]

Re: 1955 Fastwin Aquasonic Help 15 hp

Is 20% Bad

 

[1946Zephyr]

Re: 1955 Fastwin Aquasonic Help 15 hp

I would sea foam the motor and see if those numbers improve. 20% is not very good but the motor should run. I just won't idle very smoothe. Things could get better by running it too.

 

[kfa4303]

Re: 1955 Fastwin Aquasonic Help 15 hp

I agree with Zephyr. Seafoam the motor and you'll probably see an improvement and evening out of the motors performance. That stuff is amazing. I just put some in my trucks gas tank and she's running better than she has in years. Best $10 you can spend on your motor, but be ready for A LOT of smoke.

 

[Anthonyfasttwin]

Re: 1955 Fastwin Aquasonic Help 15 hp

I agree with Zephyr. Seafoam the motor and you'll probably see an improvement and evening out of the motors performance. That stuff is amazing. I just put some in my trucks gas tank and she's running better than she has in years. Best $10 you can spend on your motor, but be ready for A LOT of smoke.

Thanks guys I actualy picked some sea foam up yesterday from auto zone. I have been in there prob 5 or 6 times getting different things in the last month and every time I go some one always asks me if I want to buy the sea foam on sale for $ 6.99 Hope it will help out. Im ordering my carb kit with float today from I boats hope that will help too my float was shot. Thank you for all your help I couldent do it with out yall.