1981 Johnson 7.5 hp starting problem

renorich

Cadet
Joined
Apr 18, 2008
Messages
13
Folks, I believe I have the only outboard motor that is afraid of water! I can start it quickly ( 2 or 3 pulls) when it is out of the water, but can't start it at all when its in the water. I believe the problem is in the shifting. When it is not running and in neutral, the prop turns freely. However, when I pull the rope and it starts (out of the water of course. :) , the prop turns. It seems that when it's in the water, the rope is a bit harder to pull. I'm at wits end. Any help is greatly appreciated.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: 1981 Johnson 7.5 hp starting problem

What kind of compression do you have ?? Back pressore changes when you have it in the water.
 

raczekp1

Lieutenant
Joined
Mar 30, 2010
Messages
1,327
Re: 1981 Johnson 7.5 hp starting problem

i would drop lower unit, atache garden hose to water pipe and run water.
try start motor.if starts and run with no problems easyli it means problem is with lower unit.something is blocking gears

or drop lower uit and try to start for short period/avoid overheating cylinders/ if starts easily it means water enters cylinder becouse bad head gasket or side plate cover is bad.

atache garden hose and run water if die when water start to circulate it menans water enters to cylinder, and plugs should be wet
 

renorich

Cadet
Joined
Apr 18, 2008
Messages
13
Re: 1981 Johnson 7.5 hp starting problem

Thank you both for the imput. I will drop the lower unit and give it a try.
 

renorich

Cadet
Joined
Apr 18, 2008
Messages
13
Re: 1981 Johnson 7.5 hp starting problem

I pulled the lower unit and checked everything. All gears and pinion are fine. However, I can't get the lower unit back in without it locking the shift lever. If I back it off about an inch, then the shifter works. I did all the things the manual said, ( flat side of pinion to port, turn flywheel clockwise, etc. ) but the shift lever locks when I screw the bolts in. I put the lever in forward before I engaged the unit. I also tried neutral, but it still locks. Any suggestions? Thank you.
 
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