Swapping Motors from Mercury to Johnson

[samm835]

I have been having many many issues with my current motor a 1991 115hp Mariner/Mercury motor. Last season I had numerous electrical issues, and also now the reverse has gone out and the lower unit is leaking water into it. To say the least this motor has been full of troubles. I have only ever owned Mercs/mariner outboards, I am tired of this motor and to be honest not sure I want to put any more money into it. I found a 200hp Johnson(1987) with a ton of stuff updated. My question is, yes I know the throttle will need to be changed, and also the electrical for starting it. This is something I have never done, is it a huge pain in the butt to pull all the wires and reinstall throttle and ignition? I have a 24ft pontoon so its somewhat open to almost everything but I wanted opinions from people who have actually swapped brands of motors. If it is to much of a pain I guess I will keep looking for other motors within the same brand name. Thanks in advance!

 

[cheesegrits]

Re: Swapping Motors from Mercury to Johnson

My question would be is your transom rated for 200 hp?

 

[Silvertip]

Re: Swapping Motors from Mercury to Johnson

It is very easy to pull the old harness out. Disconnect the harness at the engine. Then remove the control box at the helm. Now, tie a nylon cord to the engine end of the harness. As you pull out the Merc box and attached harness you will pull the cord with it. Starting at the helm, tie the cord you pulled through to the engine end of the Johnson harness. Go the engine and pull the cord and the Johnson harness through. Two people may be necessary as one will need to guide the harness while the other pulls. It may snag on stuff in the gunnel area so just pull back and forth to work the cable through. You will need the steering link for the Johnson but the steering itself does not need to be changed. Battery hookup is the same. Pos cable to the solenoid, Neg cable to the engine block. Mount and hook up the oil resevoir and fuel lines. Be sure to prime the oil line before hooking it up.

 

[tashasdaddy]

Re: Swapping Motors from Mercury to Johnson

best move you ever made. just had to say that.

 

[kenmyfam]

Re: Swapping Motors from Mercury to Johnson

Guy down the street has the same Mariner..........and the same issues you had. I told him I can help him when he gets a Johnson or Evinrude.

 

[samm835]

Re: Swapping Motors from Mercury to Johnson

This Mariner will be the death of my wallet or it will be for only target practice. If I buy another motor type, I would even feel bad selling it as a parts motor. I have always have Mercury's bad this motor is a PIECE! Thanks for the help guys!

 

[bob johnson]

Re: Swapping Motors from Mercury to Johnson

my buddy went the other route!!! 1988 evinrude 88spl to 1990 merc 80 hp on his pontoon...I couldnt be happier!!

I got the old evinrude and the controls!!!!

that aside!!

I would use duct tape to make a nice smooth bullet shaped connection between the harness you are removing and the wire line/rope you intend to pull the future harness through with!
less snags...


are you getting the controls with the replacement motor??

bob

 

[seabob4]

Re: Swapping Motors from Mercury to Johnson

It's called a "de-rig/re-rig"...do it all the time...

 

[mike343]

Re: Swapping Motors from Mercury to Johnson

I have been having many many issues with my current motor a 1991 115hp Mariner/Mercury motor. Last season I had numerous electrical issues, and also now the reverse has gone out and the lower unit is leaking water into it. To say the least this motor has been full of troubles. I have only ever owned Mercs/mariner outboards, I am tired of this motor and to be honest not sure I want to put any more money into it. I found a 200hp Johnson(1987) with a ton of stuff updated. My question is, yes I know the throttle will need to be changed, and also the electrical for starting it. This is something I have never done, is it a huge pain in the butt to pull all the wires and reinstall throttle and ignition? I have a 24ft pontoon so its somewhat open to almost everything but I wanted opinions from people who have actually swapped brands of motors. If it is to much of a pain I guess I will keep looking for other motors within the same brand name. Thanks in advance!

Maybe a little older, but we had an 83 200hp Evinrude (in those days the only difference was paint). Donated the boat (still working well, didn't want the hassle of selling, trade in not an option, and not allowed on Tahoe) in 2002. Other than normal maintenance, the only problem was a diifficult solution to a temp sensor problem. Often difficult to start but that's typical.