1973 6HP Johnson, Idles, Runs Great, Stalls in Shift or Slow Position?

[Little Viking]

Hello All,

I have a 1976 Johnson 6HP (looks like new) that I picked up as a seized motor for $50 (I figured I could part it out and make $50 if need be). A shot of penetrating oil in the cylinders and a very light twist on the flywheel a few hours later (by hand) and we are no longer seized! The guy I bought it off of used it 1.5 months ago and said that it simply seized up when he was at the lake. He sold his boat and then had this motor left over.

I have the flushing muffs and decided to fire up the motor now that it is no longer stuck. It fired up on the 3rd pull. It idles great and will rev up (didn't rev it too high as the motor was not in a test tank). Trouble is that it stalls when I rotate the tiller handle control to "Shift or Slow". If I am really fast, I can rotate to shift, pop it in gear (forward or reverse) and then rotate back to idle. I can even rev it up a little while in gear and the prop spins great. I can rotate the handle back to idle and everything is great. As soon as I rotate to "Shift or Slow" it stalls? Rotate back to "Start" and 1 pull to start it back up again.

I did look up "Stalling motors" on the forum but did not run accross anything with this scenario?

Advice welcome!

The guy I bought it from put new spark plugs in, so I have no idea of burn patterns on the old plugs. I don't have a compression fitting that fits for my compression tester. Though, it fires up crazy easy so I don't know if compression is really an issue?

Thanks in advance!
Little Viking

 

[Daviet]

Re: 1973 6HP Johnson, Idles, Runs Great, Stalls in Shift or Slow Position?

You can't run that engine on muffs, put it in a barrel or trash can with the water level almost up to the exhaust port.
By the way you describe it, it sounds like the spark and compression are ok, you should still check them though.
Don't pay any attention to the shiftor slow indicators on the tiller handle, they are never in the proper place. After running the engine for awhile you will be able to hear the sweet spot for idle and shifting.
Make sure the carb low speed needle is adjusted properly, if it still acts up it's time to rebuild the carb.

 

[Little Viking]

Re: 1973 6HP Johnson, Idles, Runs Great, Stalls in Shift or Slow Position?

Don't pay any attention to the shiftor slow indicators on the tiller handle, they are never in the proper place. After running the engine for awhile you will be able to hear the sweet spot for idle and shifting.

Hi Daviet, Thanks for the reply.

The Muffs seemed to work great? Lots of water pumping out the pipe when it ran (impeller is obviously working). Not an issue to put it into a big bucket the next time I fire it up though.

As for the indicators "Fast____(space)____/Start/Shift/Slow/Stop" being in the incorrect position (potentially). From the slowest point of idle (before it stalls) the indicator is at the "Start" marking. It's running pretty quiet and smooth at this point. Am I wrong in assuming that as the tiller handle is rotated further towards "Slow" that the idle should pick up slightly? From the "Start" indicator position, it simply idles faster as I rotate the handle.

Cheers,
Little Viking

 

[rosseparker]

Re: 1973 6HP Johnson, Idles, Runs Great, Stalls in Shift or Slow Position?

I am having a similar problem with a 1957 5.5 Johnson. Did you ever find out what was the issue or did you just live with it?