Model number oddity / coming out of gear issue

[therealfordguy]

Good evening, I believe my 1990 Johnson 120hp to be a unicorn. It's a model J120TLASB serial# G 02540765. I cannot find a factory service manual that covers my model anywhere. With it being a 1990 model all signs suggest that it should be a J120TLES, and yet clearly stamped on the engine serial plate is "J120TLASB". I referenced several Johnson/Evenrude model guides I found on the internets and apparently my model doesn't exist. I recently purchased a lower unit for it to correct a coming out of gear issue and I'm trying to figure out torque specs for the prop retention nut, as well as correct shift rod height, which I could not find in the "top secret files" here in the iboats.com forums. I have a Seloc manual that supposedly covers my model, but I don't trust it for specs or technical details. Does anyone have any knowledge of a J120TLASB and why it's an oddity? Or have a suggestion of where to find an actual factory manual that covers it? I'm also not sure if it's a looper or a crossflow. The issue I'm having is that if I go above 1/2 throttle it's either coming out of gear or the prop hub is spinning. I was leaning towards the dog clutch and and forward gear since the engine is 26 years old, and it doesn't "catch up" like a spun prop might. It flat comes out of gear and I have to drop back to neutral to reengage forward gear. I used a paint pin to draw a reference mark on the hub and prop. It had definitely spun after a run on the lake and me duplicating the issue. I was under the impression that a spun prop wouldn't cause the gears to disengage though. You can imagine my excitement after replacing the lower unit only to discover it might just be a spun prop. Rookie mistake I suppose. Sorry for the ADDness and length of my question/statement, but any and all help is appreciated. Thanks!

Make: Harris
Model: Floatbote 240 Heritage 1989
Engine: Johnson 120hp 1990
Model: J120TLASB
Serial: G 02540765

 

[interalian]

Prop nut torque according to my older service manual is "finger tight then tighten to align to the next slot for cotter pin, install pin and bend tabs". I've never had a spun prop on a larger motor, but I would think that when it lets go, the rubber hub is lubricated with water and it'll really slip.

 

[hardwater fisherman]

At shop evinrude.com your model number is listed. Also your service manual was not very hard for me to find.

 

[therealfordguy]

interalian, thanks for the tip!

hardwater fisherman, finding parts for my model isn't the issue. I'm having trouble finding a factory service manual. My model number shows up on all the parts websites I've searched.

 

[hardwater fisherman]

They list a service manual for you at outboardbooks.com.