78 Johnson 150 no reverse

28sstony

Seaman Apprentice
Joined
Aug 25, 2008
Messages
32
When I bought this motor a few weeks ago I saw it run and shift just fine before I bought it. When I rigged it on my boat I used a different set of controls and cables that was already on the boat(same year OMC, just top mount instead of the side mount that came with the motor.

The very first time I ran the boat, shifting into reverse was very sloppy, I adjusted the cable until it shifted just fine into both foreward and reverse, at this point I was amost out of adjustment on the cable. After the first time out I did an impeller change, when I put the lower back together I adjusted the shift cable back so that I had equal adjustment in both directions. I then adjusted the threaded shift rod end accordingly.

Without the engine running I had someone spin the prop while I worked the shifter and made fine adjustments on the cable until the gearcase engaged solidly into both foreward and reverse accordingly. NOW, I ran the boat yesterday and have no reverse. Foreward is great, reverse would chatter a little with the shifter all the way back but not engage. I ran my cable adjustment all the way out in either direction and the boat would still not go into reverse. With the boat back on the trailer I checked the shifting again with someone spinning the prop to make sure my contorls were not slipping, and it shifted and engaged perfectly in both gears just like it did when I originally re set it after the impeller change.

What am I doing wrong here? do I need to go back and re adjust at the shift rod??
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: 78 Johnson 150 no reverse

you do not adjust the shift rod to the cables. the shift rod is suppose to have a certain length, then you adjust the cable. you need to go back and reset your shift rod to the correct length. if you cables are old, they could be stretched, or bunching up inside the sheath. i do not know the proper length, as i do not have a manual for that motor.
 

James R

Commander
Joined
Feb 1, 2007
Messages
2,679
Re: 78 Johnson 150 no reverse

Isthere any slop in the shift lever in the motor. If so it could be the bushing is worn out. Makes life difficult in setting up the shifting.
 

28sstony

Seaman Apprentice
Joined
Aug 25, 2008
Messages
32
Re: 78 Johnson 150 no reverse

There seems to be a tiny bit of slop between the "rocker arm" linkage and the shift rod coming from the lower, and exactly 1/8" of play in the shift cable itself, other than that everything is snug.
 
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