Old Johnson tn-26 and hd-25 are parts compatable?

[Ross72]

Ok, here's the background. Last summer I picked up a hd-25 from what I can tell it's a 2 cylinder 2.5 hp biult between 1946 and 1950. Powerhead is locked up, but lower unit is good along with most of the ignition

Earlier this week, my dad picked up a tn-25 which I believe is a 5 hp twin cylinder built between 1950 and 1951. Dad says it turns over ok and has decent compression.

Dad's cottage is on Pymatuning Lake in Jamestown, PA and we are headed down there Sunday for a week. I have to put a roof on the cottage and the kids are on spring break.

My question do this motors share the same coils, points, etc? I haven't been able to find a parts list online to look at and compare part numbers. I haven't seen the tn-25 yet but dad says it looks pretty good for it's age.

I will check spark, compression and fuel, just wanted to know if there were any diagrams available. Dad wants to stow the motor in his sailboat as a back up, since it has an onboard tank.

Also, is this a 16 to 1 or 24 to 1 mix ratio motor. Thanks in adavance for an advice and or suggestions.

PS. Dad got the motor for $25, so it shouldn't be too expensive even if I have to replace the whole ignition system.

 

[1946Zephyr]

Re: Old Johnson tn-26 and hd-25 are parts compatable?

I wouls start by cleaning up the points and replcing the spark plug leads. If that doesnt work, then replace the condensors. The coils on those are pretty tough old buggers and are less likely to fail, than the later universal type ignition.

 

[Ross72]

Re: Old Johnson tn-26 and hd-25 are parts compatable?

Thanks for the tip, I just figured I would take the hd-25 along incase I had to steal some parts from it.

 

[1946Zephyr]

Re: Old Johnson tn-26 and hd-25 are parts compatable?

Yea, I'm not sure the coils will interchange. Who has the HD-25?

 

[kbait]

Re: Old Johnson tn-26 and hd-25 are parts compatable?

You can lay the 2.5 on it's 'face' and add some pb blaster in the plug holes and see if it'll free up.. don't wrench hard, just move the flywheel w/your hands, and give it time to work.. If it's just storage rusted rings, it may be ok.

I think the 2.5 ('46-'50) has the really old style magneto w/guillotine pointset, and the TN'26 5hp ('50-'51) has the standard magneto used from early '50's to mid '70's. Someone w/intimate knowledge will likely chime in to confirm..

 

[1946Zephyr]

Re: Old Johnson tn-26 and hd-25 are parts compatable?

I'm not positive, but I believe the TN-26 used both styles of mags, depending on the year. I do believe it was 1951, when the universal style ignition was put in motors and 1950 was the last year of the guillotine style points.

 

[Ross72]

Re: Old Johnson tn-26 and hd-25 are parts compatable?

1946 Z, I have the hd-25 here in Corning, NY gonna load it in the trailer and take it anyhow, doesn't take up much space and only weighs about 30-40 lbs.

kbait, I took the tank off the and the points were something that I have never seen. So yes I would imagine they are the older style. They are both real cool looking old motors and I would love to get them both running, but I may not have alot of time to tinker. The roof is 22 sq and I have to tear off 2 layers and there is rain in the forecast. Well, maybe if it rains all week, I can tinker with the motors and put the roof in later in the summer.

 

[1946Zephyr]

Re: Old Johnson tn-26 and hd-25 are parts compatable?

Cool. Yea, I would try and free it up and get it running. I'm in the midst of restoring an earlier version of that (HD-20) Cool little motors, but I'm going to need to replace all the innards of my powerhead. A new crank for one of those is only $59, but what's funny, is the rods are more expensive. LOL

 

[Ross72]

Re: Old Johnson tn-26 and hd-25 are parts compatable?

Update on the TN-26

The TN-26 seems to be a 1950. It has the guillotine points and horse shoe coils. There is no spark after I checked the coils, no cracks and cleaned the points. I guess I will disassemble the points and clean them. From what I can see the points are no longer available, does any one have a source for these or can it be converted?

 

[Ross72]

Re: Old Johnson tn-26 and hd-25 are parts compatable?

Well I pulled the points out and cleaned them up and it fired up after a 15 pulls. The carb is leaking fuel from the top of the primer rod. Is there a rebuild kit available for this carb?

I haven't pulled the carb yet to get the numbers, but looked around here at iboats and haven't been able to locate the right one. Would it be better to try to get one from a small engine repair shop.

Would like to get this old girl back in running condition. Thanks for all the help so far.

Ross

 

[Chinewalker]

Re: Old Johnson tn-26 and hd-25 are parts compatable?

There's a guy at the AOMCI.org site who sells the rebuild kit for the primer. I don't have his name handy, but he advertises there a few times a year. Might be worth a post on their Webvertiser to roust him out...

As for the other bits for the carb, the float is the same size as a Mercury replacement float. It's a fairly easy conversion and has been detailed in several posts here on iboats. Gaskets you'll have to make, and some of the fiber washers can be had off the shelf at a hardware store.

 

[HighTrim]

Re: Old Johnson tn-26 and hd-25 are parts compatable?

This is what you will need for the carb rebuild. They are different from what you are used to.

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

If it is leaking from the primer this is the information you will need for the leather seals.

Send $7.00 per set (cash only, no checks) and SASE (self addressed stamped envelope) to: Lloyd Lautner, 9289 North Long Lake Road, Traverse City, Michigan 49684

Here is more general info on that motor. This site helped me tremendously on my first TN28 rebuild.

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