Topic: 1932 Johnson K-50 Starting – Antique Outboard Motor Club,Inc

This topic has 12 replies, 5 voices, and was last updated 5 years, 11 months ago by Buccaneer.

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May 13, 2018 at 1:32 am #9906
Buccaneer
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US Member
I tried starting the subject motor today. I even read the
starting instructions in the manual first! Manual says
that they are "EASY" starting engines. NOT!
I got one little pop out of it.
The manual told me……..

-hold down the float pin until gas oozes out
-lever at "choke"
-mag advanced half way
-carb needle two turns open when cold out.

It ended up with some gas dripping out of the air intake
chamber where the air horn bolts on, and I think
I seen a drop where the carb clamps onto the power head.
One would assume gas is heading in the correct direction then,
but I’m wondering if the carb is sucking air where it clamps on
to the power head. I have to tighten the clamp pretty tight
before the carb doesn’t wiggle.
I squirted gas in one plug hole for fun, and it did "nothing". 😕

Checked the spark, and it’s nice and blue. The coils were tested
good on my Stevens.
Checked compression, 68 & 73 psi.
Hard to tell with brand new plugs if they’re "wet", but gas wasn’t
dripping off them.

Not ready to get the drill out yet, but my shoulders have about
had it. Any ideas????
Thanks.

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May 13, 2018 at 2:24 am #75874
pm-t2
Participant
Canada Member - 2 Years
Did you have the powerhead completely torn down at some point? If so, did you measure the clearance on the ID of the centre main?

I think those motors have a limit of about 0.004" on that clearance. If its more, they don’t like to start. Usual result is they’ll start on a stand, but not with the prop wet.

PM T2
May 13, 2018 at 2:27 am #75875
pm-t2
Participant
Canada Member - 2 Years
Also, that carb sits on a spring-loaded sleeve that has to be properly located over the corresponding hole in the intake manifold. I always wire those carbs in place so it doesn’t get out of alignment. Used to have an A-70 that drove me nutty until I figured that one out.

PM T2
May 13, 2018 at 6:14 am #75884
Doug Wilson
Participant
US Member - 2 Years
both my A50 and K50 have to set the mag above half way maybe 60 to 70% to start . also if has not been run for a while rock the fly wheel back and forth several times to make sure it has primed the cylinders . both usually start quickly that way

Doug

Doug

how is it motors multiply when the garage lights get
turned off?
May 13, 2018 at 12:38 pm #75897
squierka39
Participant
US Member
I agree with Doug, advance that mag lever a bit past half way.
May 13, 2018 at 1:47 pm #75903
Buccaneer
Participant
US Member
No, I did not think / know better enough to measure the center main.
I figured the last time it ran, it at least ran "poorly", but not at all. 😮

quote PM T2:

Did you have the powerhead completely torn down at some point? If so, did you measure the clearance on the ID of the centre main?

I think those motors have a limit of about 0.004″ on that clearance. If its more, they don’t like to start. Usual result is they’ll start on a stand, but not with the prop wet.

PM T2

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May 13, 2018 at 1:49 pm #75904
Buccaneer
Participant
US Member
I did try advancing the mag beyond half way, and also switched spark plug
wires out of desperation, to no avail.
I think, when I have time ( I hear today is Mother’s Day) that I’ll
pull the carb back off, and try to make sure, somehow, that
it’s sealing, and tight on the power head. And maybe when
the carb is off, I can dump some vicious oil in to seal that center main.
Thanks for the suggestions!

UPDATE – I took the carb back off, and hooked it up to the fuel line to
observe if the carb was flooding thru the nozzle / pickup tube.
When I opened the fuel valve gas squirted out of the nozzle, but
stopped when the float seated the needle.

With the carb off, I squirted a little ether in the crankshaft port.
It did fire, but not vigorously. It would fire the next few pulls,
hitting two or three times at best.

I then put the carb back on, set the carb to "Fast", but didn’t
turn the fuel back on. I then commenced to pulling it over
about 15 times until my shoulders said enough.
It fired every time, but the most hits in a row was probably 5 or 6.

I cut back the carb needle adjustment from 2 to 1 turn open,
and will play with it some more tomorrow.

I’m feel confident that the carb is on tight (at least now)
and not sucking air. I noted that the carb must be pushed
onto the power head mount all the way, or there’s a chance
of air sucking thru the slotted part of the carb that the
mounting clamp squeezes tight.
Is there suppose to be any kind of gasket involved in mounting
the carb to the power head?
Thanks

quote ddwilson:

both my A50 and K50 have to set the mag above half way maybe 60 to 70% to start . also if has not been run for a while rock the fly wheel back and forth several times to make sure it has primed the cylinders . both usually start quickly that way

Doug

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May 14, 2018 at 2:38 am #75949
Anonymous
I had the same hard starting problem with my K50. As stated earlier if the center main has too much clearance the motor will not start. On an alternate firing twin that has too much clearance, the fuel charge will not be delivered to the spark plug. The way I fixed mine was to replace the crankcase with a later KA38 series one the had rings to seal the center main. The result was a great running motor. All A50 and K50 motors that have some run time and have a worn center main will have this problem. Running a 8 to 1 mix with 30 or 40 wt = Shell Aviation 80W oil may help to seal the center main.
May 14, 2018 at 12:28 pm #75965
Buccaneer
Participant
US Member
quote XR55:

I had the same hard starting problem with my K50. As stated earlier if the center main has too much clearance the motor will not start. On an alternate firing twin that has too much clearance, the fuel charge will not be delivered to the spark plug. The way I fixed mine was to replace the crankcase with a later KA38 series one the had rings to seal the center main. The result was a great running motor. All A50 and K50 motors that have some run time and have a worn center main will have this problem. Running a 8 to 1 mix with 30 or 40 wt = Shell Aviation 80W oil may help to seal the center main.

Thanks! good information to know if needed.
Are you saying you swapped just the crankcase and not the entire
power head?
I have a KA-10 and a KS15, 9.8 hp. I believe they are 1940 and 1941 vintage.
At this point, they are "not" parts motors, but I’m curious as to
what all motors would be parts donors to get the crankcase with
the center main sealing rings?
Thanks!

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May 14, 2018 at 5:17 pm #75978
squierka39
Participant
US Member
Buc, looking thru my parts catalogs shows that the K-80 was the first year to use the sealing rings in the crankcase. The K-80 and KA-37 are the last years with the full opening for the carb. The later crankcase have a odd shape with a small hole for the idling intake. It appears it worked fine with the later ones for XR55. So any block from K-80 up would work. Hopefully you can get it going without swapping.
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1932 Johnson K-50 Starting

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