Help Prepping a 1951 Johnson TN27 for use

440racer

Seaman Apprentice
Joined
Apr 21, 2008
Messages
35
The old outboard is a johnson 5 hp with TN 27 stamped on the side of the power head.

I can't believe it but it hasn't been cranked in about 10 years.

I put fresh gas in it. Opened the valves, pumped the primer and IT CRANKED.

Didn't run very well but it did run.

Now I'm looking for advice on prepping it for use such as lubrication, fuel, technique etc.

Is there a way to run it without having to have it in the lake? I was planning to use one of those clamp on things you hook a garden hose to but I couldn't find the water inlets on the leg?
 

Reggie08

Petty Officer 1st Class
Joined
Mar 31, 2008
Messages
243
Re: Help Prepping a 1951 Johnson TN27 for use

Start with this post:

Awakening a Sleeping Motor

It should give you a good starting point. Personally, I'd change lower unit oil, impellar, plugs and clean the carbs real good
 

440racer

Seaman Apprentice
Joined
Apr 21, 2008
Messages
35
Re: Help Prepping a 1951 Johnson TN27 for use

Thanks for the feedback!

I ordered a new impeller today and will install new plugs, check and re-lube the lower unit, and clean the carbs over the next few days.

Start with this post:

Awakening a Sleeping Motor

It should give you a good starting point. Personally, I'd change lower unit oil, impellar, plugs and clean the carbs real good
 

popsmazz1

Petty Officer 1st Class
Joined
Oct 13, 2006
Messages
276
Re: Help Prepping a 1951 Johnson TN27 for use

you have to put in a drum of water there is no way to hook up muffs to those motors
 

440racer

Seaman Apprentice
Joined
Apr 21, 2008
Messages
35
Re: Help Prepping a 1951 Johnson TN27 for use

Thanks! A drum of water it is.

I said I was going to clean the carb as reccommended but I'm not sure where the carb is.

The fuel seems to mix in an orifice right at the inlet to the cylinder manually controlled by a needle. The fuel going to this orifice comes from a complicated looking thing on the side where fuel goes from the tank and has a pump on it. I guess this is the carb? Any secrets on cleaning it?
 

440racer

Seaman Apprentice
Joined
Apr 21, 2008
Messages
35
Re: Help Prepping a 1951 Johnson TN27 for use

I've taken all the steps on "prepping a motor" and cranked it again this weekend.

I was a little concerned about cooling because I couldn't figure a way to make sure that the metal pipe from the impeller to the power head was connected properly, it just seems to slide into a grommet on the top of the impeller.

I now have two questions if anyone can help.

How long from the time the motor is cranked should it take for water to mist out of the motor? Its coming from two places when it does. One is from a small hole on the elbow fitting where the pipe exits the leg to the pipe going to the cylinder head and the other is two small holes on the leg just below the collar for the motor to turn on the mount. Water squirts/mists from both places but it takes a good while after the motor is running for it to start misting. The water exits my 1994 Johnson 200hp almost immediately so that's what I'm used to.

The other question is about adjustment of fuel. I can get it to crank by setting the engine speed to fast and it will run fair on fast but when I try to slow the speed to medium or slow it won't keep running. I try to adjust the richness knob on the top and the mixture screw/lever on the bottom but just can't keep it running. I had someone tell me that I would never get it to run properly because these motors were built to run on leaded gas. Could this be the reason and if so should I try some lead additive?

Any insight would be appreciated.

Thanks,

Scott
 
Top