Johnson TN26 rebuild questions (newbie)

First off - what a fantastic website / forum for collected wisdom on all outboards. I have just acquired a 1950/1 Johnson Seahorse 5HP TN26 (SN 102941). It is in great shape (I think) and destined to go on a seaflea that I am building. It doesnt run yet, but was well put away.
Bottom end been drained and refilled with correct oil.
1. Water pump : where is it and how can I get it out to look at it / get a new impeller?
2. Compression : I have measured this on both cylinders to be about 40 psi which seems low. Should I even be bothering with a rebuild? This was done with a slow wrench on the flywheel bolt.
3. Rebuilt the carb, but it still has the old cork float in it and leaks a lot now. Advice on where to get carb rebuild kit from please and what parts are likely to need replacing.
4. Fuel tank : drained, cleaned and pressure checked. All good, even the supply tap.
5. Electrics : in great shape really.
Has the central round magnet although this is not very strong - should it be? If so, can I re-magnetize it?
Coils look great as do the points including bakelite actuators - will clean & gap accordingly (20 thou right?).
Hard to tell if the condensers are OK ; is there a simple way to do this with a multimeter?
Plug wires are a little shoddy - again, where to be sourced.
Plugs looked OK, but should be replaced as a matter of course right? (30 thou gap?)

Sorry to lump all these questions together, but I am sure that all this and more is in this forum. Looking forward to making some real progress on this one soon as the flea is almost complete!
cheers & thanks in advance.

Re: Johnson TN26 rebuild questions (newbie)

welcome to iboats!
firstly you should try to give the motor a few good hard pulls to check compression in both cyls. post back with numbers. heres a link to a good site for info on your motor http://www.pochefamily.org/outboard/CarbService.html

there is a guy that will re-do your water pump, and another guy that makes the leather seals for the primer button. but as i mentioned, do a proper compression test before getting to deep into it. hopefully someone else will chime in with the info on the impeller , and the primer button seals.

Re: Johnson TN26 rebuild questions (newbie)

nwcove said:

welcome to iboats!
firstly you should try to give the motor a few good hard pulls to check compression in both cyls. post back with numbers. heres a link to a good site for info on your motor http://www.pochefamily.org/outboard/CarbService.html

there is a guy that will re-do your water pump, and another guy that makes the leather seals for the primer button. but as i mentioned, do a proper compression test before getting to deep into it. hopefully someone else will chime in with the info on the impeller , and the primer button seals.

Click to expand...

This carb service page is fantastic and very practical too. Great reference and I will be buying the leather seals too. I will report back with real compression figures shortly when I have the puller back on etc.. Thanks so far!

Re: Johnson TN26 rebuild questions (newbie)

If I read your post correctly, which I may not have, you used a wrench on the crank nut to check compression? If that is the case, that is not a good way to test. You will never get proper readings like that, Im surprised you got 40psi actually!

There is no carb rebuild kit that you can buy. Anything needed for the carb is a make yourself deal. The leather washers mentioned you can buy from Lloyd Lautner, I will send you his contact info. If the primer is leaking, that is exactly what is wrong. Where is the carb leaking? The link provided by nwcove is about the best help you will read for that motor, go over all the links provided, here is the main page. It goes over ignition testing as well.

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

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 another helpful link.

http://hoodad.fortunecity.com/index2.html

F_R from this forum has the impellers, you can PM him on here, or he may come across this thread. The trouble is they dont make them anymore, so the hubs need to be bored out to fit the driveshaft.

Plug wire can be bought from NAPA, you need 7mm copper core, dont get graphite auto wire. Plug gap and point gap is as you mentioned. Any other questions let us know.

Re: Johnson TN26 rebuild questions (newbie)

Confirming I have the impellers. Send me a PM.

Re: Johnson TN26 rebuild questions (newbie)

HighTrim said:

If I read your post correctly, which I may not have, you used a wrench on the crank nut to check compression? If that is the case, that is not a good way to test. You will never get proper readings like that, Im surprised you got 40psi actually!

There is no carb rebuild kit that you can buy. Anything needed for the carb is a make yourself deal. The leather washers mentioned you can buy from Lloyd Lautner, I will send you his contact info. If the primer is leaking, that is exactly what is wrong. Where is the carb leaking? The link provided by nwcove is about the best help you will read for that motor, go over all the links provided, here is the main page. It goes over ignition testing as well.

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

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 another helpful link.

http://hoodad.fortunecity.com/index2.html

F_R from this forum has the impellers, you can PM him on here, or he may come across this thread. The trouble is they dont make them anymore, so the hubs need to be bored out to fit the driveshaft.

Plug wire can be bought from NAPA, you need 7mm copper core, dont get graphite auto wire. Plug gap and point gap is as you mentioned. Any other questions let us know.

Click to expand...

So, after lots of cleaning, timing and pulling, the motor started, but I am getting ahead of myself :
- compression measured at about 85-95 psi for each cylinder which seemed worth doing
- got the plugs to spark by lapping the points surfaces and making them more springy. Measured the resistance which was helpful here.
- checked the primary & secondary coil resistances as they should be
- carb prime pump leaks like a sieve (leather washers ordered from Lloyd already)
- DID NOT START. Tried pulling in neutral and it sounded like it wanted to go, but couldnt. Played with the mix and still no joy. Plugs came out wet (flooded?). Dried and re-installed. Went to "FAST" setting in gear and it started. Only ran for about 20 seconds and then died and wouldn't restart.

Question : any ideas as to why this might be?
Question : will replacing the plunger leather seals fix it?

thanks again in advance. Getting excited to see this working properly.
Dave

Re: Johnson TN26 rebuild questions (newbie)

That compression is fine for a TN, no problems there.

Point gap is 020

Coils arent cracked/original are they?

Start by setting both jets 3/4 of a turn out from lightly seated.

Re: Johnson TN26 rebuild questions (newbie)

Here is a brief bit on the unique carburation on these old rotary valve 2-stroke motors. I posted it in a similar thread about a month ago. For low speed there is simple a little L-shaped rod on the front of the motor that juts out from under the lower shroud. That rod is for the low speed fuel flow. The carb on the side is used for mid-to-high speed.

http://forums.iboats.com/attachment.php?attachmentid=138239&d=1332809068

http://forums.iboats.com/attachment.php?attachmentid=138242&d=1332809696

Re: Johnson TN26 rebuild questions (newbie)

So, been a week or three since I gave an update. Got the impeller and installed - thanks Frank.
Got the leather washers for the primer piston in the carb - thanks Lloyd.
Great instructions on the carb rebuild too - thanks all.
Now, the latest - I had to use the tap idea to get the primer piston brass tube out. After some persuasion it came out OK. Then the washers. These were solidly corroded to the side walls. Had to destroy them to get them out and the leather ones were basically dust by now. So the obvious question : anyone know if I can still get these cupped brass washers as they are fairly specialised things?
My seaflea will be finished next month and I really want the launch to be with an "age appropriate" motor.
Again, many thanks in advance to you all for any help.
Dave.

Re: Johnson TN26 rebuild questions (newbie)

You've got a great motor there...got one myself. I think it's my best running motor actually. The coils and ignition are basically indestructable. They can idle way down low too!

Sorry, but no help on the the brass washers. If you cannot find them, post a "free" ad on the antique outboard motor club's website (amoci.com).

Someone will gladly help you out. Those motors were built so well that they are still very common so there are looks of used parts available.

Here is a youtube vid of mine: http://www.youtube.com/watch?v=F-Ii22TMMeo

Good luck,

Mas

Re: Johnson TN26 rebuild questions (newbie)

Also...16:1 fuel/oil ratio!

Mas

Re: Johnson TN26 rebuild questions (newbie)

Hey I was wondering were to get a impellor and maybe a water pump rebuild kit for a tn26 1951 Johnson 5hp. I guess I was reading there is no rebuild kit for the carb so I am going to refurbish it and get the leather washers but I am wondering about the water pump.


Please help

Re: Johnson TN26 rebuild questions (newbie)

Read up above. F_R has them

This is a great thread but it is 7 years old. Is the source info for primer pump leathers still valid? I just bought a TN26 and am working on getting it running.