1975 Johnson 40 hp

[chrisk92]

I just bought a boat that has a 1975 johnson 40 hp motor, the guy I bought it from had problems last summer with it slipping out of gear. He replaced the lower unit and put it away for the winter. I just bought the boat from him and after some tinkering it runs smoother, but I still have the same problem. Which brings me to my question. What else would cause it to slip out of gear at about 1/4 throttle besides the lower unit? I am not too much of a mechanic but if I had someplace to start It would be a great help. Thank you.

 

[MGuckin]

Re: 1975 Johnson 40 hp

chrisk92,<br />If the original lower unit had the same problem. Chances are it is related to the linkage, rod or cables. Probably not completely engaging. It is a very simple adjustment. Do you have the manual? <br />Mike<br />

 

[steelespike]

Re: 1975 Johnson 40 hp

Chris, yes a manual is a must. Good luck.

 

[fireman 757]

Re: 1975 Johnson 40 hp

there is a small (three inches or so) inspection plate about halfway down your lower unit. It is held on by two screws. remove this and you will see two rods that feed into a brass clip held by two bolts. Loosen the top bolt and put your engine in reverse. this should push that rod farther into the clip. tighten the bolt back up and shift from forward to neutral to reverse and see if it "clunks" into these gears better. It might take some tinkering to get this right but beats paying a dealer for it. Is this a tiller handle engine or do you have steering controls. Your transmission cable might just need to be adjusted at the engine hookup. Twist the adjustment to where it will smoothly go into all gears.

 

[chrisk92]

Re: 1975 Johnson 40 hp

Thank you all for your advice. I do have the johnson repair manual but I just wasn't sure where to begin. Fireman, I will try your advice and see what that does. I was sure it is something fairly simple and hopefully I can get it taken care of. (I got the boat, trailer, and motor for just $500.00) It would be a blessing if I could get it running 100% without getting any profesionals involved; because as far as I can tell it is in excellent condition except for the gear slippage. Thanks again.

 

[fireman 757]

Re: 1975 Johnson 40 hp

I assumed (I know never do that) that you already adjusted the transmission cable if you have a steering console. If it is a tiller handle you have to go the first route. It can be aggravating but make sure you take your time. If you get frustrated throw a tool that is guaranteed for life. Walk away from it for a little while and it will probably go smoothly when you return.