1936 K-80

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bjensen64
Posts: 53
Joined: Thu Nov 24, 2016 3:15 pm
Location: Poquoson, VA

1936 K-80

Postby bjensen64 » Mon Feb 12, 2018 6:42 pm

Trying to get subject motor started. So far I've only gotten it to run a few revolutions and/or pop a few times.

- Fuel tank cleaned, carb disassembled and cleaned, all passages blown clear. Fresh fuel mixed at 11-1
- New plug wires installed, coils good physical condition, good spark using test light.
- Points cleaned and set a 20
- Original(?) Champion, 5M plugs have been cleaned and gapped at 30 (did not check spark at plug, just used my test light)
- Compression on both cylinders is ~60 psi

What are good initial setting for the high and low speed mixture screws on the carb?
Is there a static timing setting I should be accomplishing?

Any tips appreciated.

SquierKA39
Posts: 166
Joined: Sat Aug 12, 2017 10:44 am

Re: 1936 K-80

Postby SquierKA39 » Mon Feb 12, 2018 7:50 pm

The instruction on the tank state, open needle valve one full turn, set choke to extreme right, set timing lever a little right of center, press down float pin till fuel drips from overflow pipe. Spin motor with rope, when it starts turn choke back to original position. Advance magneto to high speed and close needle valve to where motor runs fastest. When the motor is warm it should start without opening needle valve.
Good luck, hope this helps. I’m working on a K-80 now.

need2fish
Posts: 50
Joined: Fri Mar 20, 2015 1:22 pm

Re: 1936 K-80

Postby need2fish » Mon Feb 12, 2018 7:52 pm

Sounds like fuel starvation -- is the carb bowl full at all times ?

Sometimes older coils have broken wires inside -- when they heat up they misbehave ... do you still have a hot spark after the motor stops ?

I've never been up close and personal with a K-80 -- if it has an exhaust cutout are you running with it open or closed ? Closed creates more back pressure.

My K-70 and A-65 suffer from carbon buildup where the engine block joins the leg -- it creates a lot of backpressure and therefore exhaust gas hangs around along longer in the combustion chambers.

WRT to the 60 lbs compression -- it probably won't run well with either the cutout closed or clogged exhaust ports.

SquierKA39
Posts: 166
Joined: Sat Aug 12, 2017 10:44 am

Re: 1936 K-80

Postby SquierKA39 » Mon Feb 12, 2018 7:55 pm

Good point on the carbon build up need2fish. The K-80 is nearly identical to your K-70 except for the carburetor.

bjensen64
Posts: 53
Joined: Thu Nov 24, 2016 3:15 pm
Location: Poquoson, VA

Re: 1936 K-80

Postby bjensen64 » Tue Feb 13, 2018 5:41 pm

SquierKA39 - Thanks for the tip about the instructions that go on the tank... I'll have to get a set of those.

need2fish - The float pin is raised and I can push it down until fuel drips from the overflow pipe so I think I'm good there. I've also wondered about the coils breaking down - is there a good test? I didn't check for spark while the motor was still warm the one time I had it going a little. Will try that again this weekend. Should be fairly straight forward to pull the powerhead and check for carbon build up.

Thanks to both of you for the tips, I'll report back with my findings after I get a chance to work on her.

SquierKA39
Posts: 166
Joined: Sat Aug 12, 2017 10:44 am

Re: 1936 K-80

Postby SquierKA39 » Tue Feb 13, 2018 6:10 pm

The condensers will go bad before the coils. The Johnson coils are pretty good.
There is a small cover on the back of the exhaust housing, unless you have the cutout lever, the cover is held on with two bolts. Take it off to open the exhaust. See if it runs any better, if so then the clogged leg could be the problem.

If your testing it in a test tank these motors don’t pump water well or at all unless on a boat. You probably already know but it has no pump, the prop and some forward motion is necessary to get it flowing.

bjensen64
Posts: 53
Joined: Thu Nov 24, 2016 3:15 pm
Location: Poquoson, VA

Re: 1936 K-80

Postby bjensen64 » Thu Feb 15, 2018 4:03 pm

I do have the small cover on the back, thanks for the tip.

Any recommendations in regards to condenser part numbers that may be a available locally? Easy enough to change, might as well swap them out.

ddwilson
Posts: 253
Joined: Wed Mar 11, 2015 1:05 pm
Location: Carmel, IN

Re: 1936 K-80

Postby ddwilson » Fri Feb 16, 2018 12:19 am

I have used 60s Chevy condensers on both an A50 and K50
Doug
Doug
Member MOB Chapter
1930 Johnson A50
1932 Johnson K50
1951 Wizard WG7
1953 Wizard WH7
1958 Johnson QD19
1959 Johnson CD16
and the list goes on........

bjensen64
Posts: 53
Joined: Thu Nov 24, 2016 3:15 pm
Location: Poquoson, VA

Re: 1936 K-80

Postby bjensen64 » Fri Feb 16, 2018 9:15 pm

I did pull the cover plate and checked for carbon, looked pretty clear to me. After that, I pulled the mag to maybe change/re-stuff the condensers (I asked more condenser related questions in a separate post) and found the wiring going to the kill switch was pretty well shot and likely grounding out on the mag plate. Replaced those wires and ensured the wiring on the condensers was solid (I slipped some heat shrink over the leads) and reassembled. After a full pulls she started for the first time in many years (likely close to 40 or more). She smoothed out pretty well after a few seconds and settled down to pretty good idle (only ran for a couple of minutes, its getting kinda late here, ha).

Thanks everybody for all of the inputs, maybe I'll post a short vid later this weekend.
Attachments
Mag plate.jpg
Mag plate.jpg (56.87 KiB) Viewed 303 times

ddwilson
Posts: 253
Joined: Wed Mar 11, 2015 1:05 pm
Location: Carmel, IN

Re: 1936 K-80

Postby ddwilson » Fri Feb 16, 2018 10:42 pm

Great news glad to hear you got it running
Doug
Member MOB Chapter
1930 Johnson A50
1932 Johnson K50
1951 Wizard WG7
1953 Wizard WH7
1958 Johnson QD19
1959 Johnson CD16
and the list goes on........


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