Johnson Tuning

[mike-stroz]

I just got my KA-38 running for the first time in probably 40 years! I’ve been trying to tune it for about an hour or so now, but I can’t seem to get it dialed in. Any suggestions about some baselines I can start with? I’m pretty new and none of my other motors have had a high and low speed adjustment, only a single one. Also, should I check out the water pump? I haven’t taken anything apart, but not sure if it’s a rubber impeller or what.

[Mumbles]

When I had my KA 37 running on a stand once, I think the high speed needle on top was only out about a quarter turn or so for it to run right and it was very sensitive to any adjustment. I can’t remember how much the low speed needle was out. These motors don’t have a water pump but rely on the boats forward motion and propeller wash to force water thru the motor. It’s a pressure-vacuum system but the motor can be run on a stand if a garden hose is adapted to the pipe fitting on the bottom of the cylinders. Since they have a large rotary valve with sealing rings on the crankshaft, they need an 8:1 fuel mix. That’s one pint of oil to one gallon of gas.

[mike-stroz]

Thanks, I was running it on 8:1 leftover from my PO. I’ll see if I can get it running well with that setting on the high speed adjustment

[mike-stroz]

Just fiddled with the carb some more and I can’t seem to get it to run right for very long no matter what I do to the screws.

[Mumbles]

How are the condensers? Are they the originals? The should read around .22 uF if you can test them.

Old condensers never die, they just fade, fade, away.

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[mike-stroz]

Not sure about the condensors, I just left everything alone except the plug wires since it gets good spark. That manual is exactly what I needed, thanks

[mike-stroz]

Got it all tuned up. Heade up to the lake next weekend to put it to the test, just needs a new cotter pin

[mike-stroz]

Just took the Johnson out for a spin, and it runs awesome! I finally have a reliable old motor to use regularly on my rowboat

[Mumbles]

Sounds great! 😀

Now you’re giving me inspiration to get the decal on my tank and try the KA out on the lake! I’ve never had it running on a boat yet!

[mike-stroz]

The last thing I need to do is coat the cork float, that’s the one thing I forgot when I put the carb back together. Started gushing gas out the carb after a while.

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