TN26 resurrection

[vikkip]

Greetings. I am brand new to outboard motors and don’t even have a boat, but I inherited a 1950 TN26. Overall it’s in really good shape but was put away 50 years ago with carb issues which didn’t heal themselves over time. The spray from the overflow port coated the whole powerhead and upper shaft with fuel mix. It had been neglected so long that everything is still original, which I appreciate. I’m not looking to do a full "restoration" at this time, just to restore it to good operating condition so I can clamp it to my father in law’s little rowboat in place of the also horribly neglected Clinton 5hp that can’t go upwind without rowing assistance.

The carb was full of tar like goo, oil, and varnish. I’ve successfully and carefully cleaned it thoroughly. The diagrams all seem to show that there should be a brass tube in the primer pump but there is no sign that one was ever present. The leather seals are good and pliable, they were submerged in oil and actuating the plunger gives a nice puff of air through the ports.

How do I safely clean the tubing and "Y" and slow speed needle? I can’t dismantle it.

The fuel tank had been left full but had drained and evaporated to lead oxide dust, which protected the tank from rust. I removed the filter and petcock and cleaned all pieces. I dried the tank for 24 hours in my egg incubator at 100F which did no harm but thoroughly dried the seams.

The float was very soundly stuck in its bore but I was able to gently free it. The shellac or varnish that once coated it had deteriorated into sticky goo so I cleaned it off and worked the float pin out. The cork is now mostly bare. It’s overall sound but is a little crumbly around the edges, and would need to be completely resealed for use. I’m trying to get some nitrophyl to craft a replacement but I am open to suggestions on replacement…such as a new float turned from extra select cork. It’s easy enough to replicate the size of the cork, but that’s not all it takes to set a float level. How do you calibrate a new float to provide the correct amount of lift so that the inlet closes at the correct fuel level? Is there a specification for the correct fuel level?

I have not yet drained the gearcase nor examined the water pump impeller but I’ll assume it needs replacement. The seals don’t look to be leaking but I expect they will after I open it up.

My research has led me to believe that J6C plugs, TCW-3 2 stroke oil at 16:1, and Johnson/Evinrude Hi-Vis gearcase lube are the recommended maintenance items, is this correct?

Thanks in advance for advice.

[steveh]

Welcome Vikki. The first motor I did was a TN-26. Here is a good spot to start that will answer many of your questions:

http://www.pochefamily.org/outboard/CarbService.html

Lots of good info there. If you still have questions, just ask. And again, welcome!

[reivertom]

Sounds like you have done your homework. You can use carb cleaner in the hard to reach places and if you have an air compressor, blow all the small tubes and crannies out with an air gun. Pipe cleaners are your friend also. You are correct about the 16/1. Folks will swear you can run them on less oil because of the improvements in lubrication, but why take a risk? That motor has bushings instead of needle bearings like new motors, so the more oil, the better. If you feed it right and take care of it, it might outlast you.

[vikkip]

Thanks for the speedy reply. I did find this site, and the "Brass cylinder" just isn’t in this carb. It must have been lost sometime in the past. Are they available? What is the purpose, to keep the brass and leather seals down at the bottom of the bore? The pump plunger rod by itself makes a nice discharge thanks to the friction between the leather and the plunger rod.

I was going to get a high quality cork to turn down, but looking at the original again it is pretty low grade cork. But since the float is pinned to the valve at a specific height, the fuel level isn’t really adjustable except for changing the buoyancy or height of the float. The old float is approximately 30mm diameter x 30mm height. I suppose I could reinstall it and see where it closes with water in the bowl, and match the level with the replacement. Too much buoyancy would close the valve too early and leave a low fuel level and too little buoyancy would act like a sunk float and allow too much fuel into the bowl. I don’t know what the correct fuel level is.

This motor already has a few years on me and should do it again. I live in a house that will turn 200 in 6 years so I appreciate old, well built things and know that old does not necessarily mean well built. I have a few ’70s two stroke dirt bikes, which are perhaps the most abused machines on the planet but it’s still easy to get parts for them. I have fun fabricating within reason.

I do have an air compressor and the carb is well cleaned. I did a nice soak in 50/50 Pine-Sol and hot water in my ultrasonic cleaner on all the castings, followed by a solvent flush. The check valve is now free and works correctly, it looked like a lump of tar when I removed it.

I have not yet figured out how to get to the water pump impeller. I did get the nut and prop off.

[cajuncook1]

VikkiP, if you send me a PM of your email address, I can send you a pdf of a digital parts manual and owners/instruction manual.

Look at my username in the post and click the contact bubble below my name so the whole world wide web does not get your email.

If you are missing parts, you can use the parts manual to determine what parts are missing and place an add in the Webvertise section of this forum. Please read the posting instructions for posting an add or it may get deleted. There are plenty of AOMCI members that have parts motors. You will notice that the official AOMCI member’s names are red in color. This will help prevent someone not known to the organization from scamming you.

Cheers,

cajuncook1

[shoestringmariner]

Sweet! I think I’d prefer an untouched find like that opposed to one that has been run on 50:1. You will need to slightly modify an impeller avail at Napa, and coils will be junk for sure…new are easy to find for cheap. Sounds like your primer is good, but should you need one, it can be had through a contact here for a reasonable price. Got any pics?
I have a few TN’s, might be able to help with parts if you’re close.

[shoestringmariner]

Here’s some past threads that may be relevant; (The 26 is very similar to the 28)
viewtopic.php?f=2&t=7183

Some threads here of my questions regarding my TN-28 and lots of help from the members
viewtopic.php?f=2&t=399
viewtopic.php?f=2&t=628
viewtopic.php?f=2&t=494
viewtopic.php?f=2&t=530&p=2812#p2812

Impeller; http://www.pochefamily.org/outboard/ImpellerConv.html
Carb; http://www.pochefamily.org/outboard/carbservice.html
I used model airplane dope on my float and it seemed to work well.

FYI:, if your leather seal is dry at all, it will leak at the plunger stem.

[vikkip]

I removed the plate behind the prop (3 screws) and let the oil drain. Only about a tablespoon came out, with the consistency of old honey. Not good. There is a rubber seal and a bronze sleeve in the cover, and the prop shaft shows some scoring. I can feel it with my fingernail, but there is no wobble in the prop so I’m not sure how big an issue it is.

**deleted, thanks to the wonderful info above I know where to find the impeller now** 😀

Thanks for all the info above, I will study up.

[Mumbles]

The Johnson TN 26 motors are water cooled. The impeller is up inside the exhaust housing, not in front of the prop, as the TD rotors are.

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Attachments:

TN-26 User Manual.pdf

Parts List TN26.pdf

[vikkip]

The impeller is, amazingly, in perfect shape, soft and flexible and not worn. I can bend any two vanes together with no stiffness, and they return to the original position.

[Author]

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