Just got a 1957 18hp johnson seahorse

I

iowa84

Seaman Apprentice
Joined
Mar 10, 2011
Messages
40
Re: Just got a 1957 18hp johnson seahorse

I'm not gonna take it out until Im sure it wont break down on me. When I turn the tiller handle. it doesn't rev or anything, where should I check and what should I look for? I do have a spring that I is on the side of the motor that is playing no part in anything, maybe that should be connected to the carb?
 
BassBlaster29

BassBlaster29

Seaman
Joined
Mar 12, 2011
Messages
54
Re: Just got a 1957 18hp johnson seahorse

The carb is very very sensitve. If you have a carb issue, its best to take it off and do a clean and rebuild. You wanna get all that old gasket material out of it and get some new in anyhow. The material used in the 50's wasnt resistant to alcohol and other chemicals thats in todays gas. Just tear it down and clean it up with carb cleaner and a tooth brush. Compressed air comes in handy for drying all the parts and blowing out the small passages. Then find the article in the "top secret file" about adjusting carbs and you'll be in business.

I have tore down a few carbs in my day. This one is by far the simplest thing to work on. Thaeres not much to it. If you order the Sierra rebuild kit, it comes with really good instructions and pictures.

If you take the carb apart, might as well get rid of that cork float and put in a new plastic one too.
 
Sea18Horse

Sea18Horse

Chief Petty Officer
Joined
Jun 1, 2008
Messages
626
Re: Just got a 1957 18hp johnson seahorse

iowa84 said:
I'm not gonna take it out until Im sure it wont break down on me. When I turn the tiller handle. it doesn't rev or anything, where should I check and what should I look for? I do have a spring that I is on the side of the motor that is playing no part in anything, maybe that should be connected to the carb?
Click to expand...

Does the movement of the tiller handle transfer from the front shaft to the rear shaft and then from the tiller gear to the vertical gear to the vertical throttle shaft and then to the mag plate? And when the mag plate rotates does the cam follower roller at the front of the mag plate activate the linkage to the carb? I've had a pin in one of the tiller hinge gears shear off once. I've also seen the nylon pin in the bottom of the vertical throttle shaft shear off before. If you're getting movement all the way to the throttle linkage then the problem is likely inside the carb. You'll want to get a carb kit and float if you haven't already and redo the cleaning. Perhaps you missed something in the high speed jets.

As for the spring. They often have a spring behind the vertical throttle shaft the end of which fits around the spark plug wires. It keeps the plug wires under control as the mag plate rotates. Could that be the spring you see? Good luck!

Cheers.....................Todd
 
I

iowa84

Seaman Apprentice
Joined
Mar 10, 2011
Messages
40
Re: Just got a 1957 18hp johnson seahorse

yes, that's the spring that is around the spark plug wires. Tomorrow I will get back to work on the motor and everything and keep you updated on everything.
 
I

iowa84

Seaman Apprentice
Joined
Mar 10, 2011
Messages
40
Re: Just got a 1957 18hp johnson seahorse

Ok, I have 2 problems and I'm good to go. 1. theres a clamp type thing in the housing that connects the shifter bars the one side is stripped out and keeps coming apart the bolt in it will not tighten down, I hope i explained that good enough for you to know what part I am talking about..just in case ill explain it more, you have the drive shaft and the other bar that is for shifting in the middle they separate when you loosin the bolt the part that connects them..there that should hopefully explain it better..I NEED THAT PART anyone know where to get it? or a good improvise? For my 2nd problem, The darn rivers and lakes are all flooded!
 
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