68 johnson 55hp low speed adjust(?)


Old 09-18-05, 05:14 PM
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Join Date: May 2004
Posts: 65
68 johnson 55hp low speed adjust(?)

Hi all, i have the above motor, just got the boat, starts, runs good, the only issue is: when i go from neutral to forward, it wants to die. sometimes, it's OK. it almost acts like it's loading up. then, if re-start, drop it in forward, and hammer it, she holeshots like a switzer! going from wide open to slow seems fine, but starting from a dead stop shows the problem (?) a friend thinks we should look into the low speed on the carbs (?)
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Old 09-26-05, 09:07 AM
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I have a 69 Johnson 115 that I rebuilt from the block. Beautiful piece of engineering except for one thing I never understood - the drive shaft doesn't mate tightly with the cranks shaft! The spline on the drive shat was worn half thru' so I replaced it and have been very careful with it since. However when I had the lower unit off some years ago I was dismayed to see that the new shaft was worn just the same.

About 3 "holeshots" and I'd be paddling!! Never Move the control quickly in either direction - move the control slowly untill you feel the gear engage, then you can "hit it".

My motor displays the same problem you discribe, especially when she's cold. This old 4 cylinder is very difficult to tune so we haven't touched it for a dozen years and it used to be on a ski boat so was tuned to accelerate.

I put it down to too much oil (running too rich) and usually a few seconds with the fast idle control will clean her out enough to get me moving.

Also watch your oil mix. We put a litre in 5 gals - that's 1:45 not 1:50 and since we're running rich (5%??) that would be more like 1:42.

Good look and I'm interested if anyone else has some solution.
Old 09-26-05, 05:47 PM
Join Date: Aug 2005
Location: nc
Posts: 369
68 johnson 55hp low speed adjust

well your buddys right it is the low speed getting to much gas . but being the old johnson id agree with the last guy its hard to ajust the carbs so be carefull with it if you make ajustments rember were you started with the the setings in case you need to go back to what you had to start

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