Switching from Johnson to Mercury

Buster_boy

Petty Officer 2nd Class
Joined
Aug 9, 2015
Messages
178
My 16ft pontoon has a 40hp Johnson installed from manuf. I may decide to remove it and install a Merc 9.9hp instead, making it a restricted Water boat. How difficult is it to switch the ignition and controls from Johnson to Merc? I know I'll need top mount Merc controls, but what else?

I'm not a complete idiot, just a half of one, and some things are better left to the pros. Is this one of them or can I do this myself in a weekend?
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Very simple switch, remove the motor and all the Johnson controls, then mount the Merc and its controls.
 

Yegboats

Chief Petty Officer
Joined
Feb 20, 2016
Messages
511
Assuming you're going to go with a new Merc 9.9 0R052327 serial number and above. (w integral trim)
1x Console mount control (top mount) 8m0059686
2x Mercury gen II cables 897978aXX length tbd
1x 84-896537TXX (T15') (T20') (T24') engine ignition/choke harness length tbd
1x 87-88107a13 key switch assy with choke
1x 84-896541T01 Adapter harness ( The large round end with 14 female holes receives the 14 male pins from 84-896537txx which lets you plug it to your engines white power plug"engine amp connector")

Instrumentation you may consider
1x 84-892990t01 Analog gauge harness
1x 6k tach 79-895283axx (a03) (a23) black/white gauges

If you don't want gauges you can probably save some money by going this route
​1x Ignition/Choke Assembly 8166266AXX (20') (A24')
1X Adapter Harness 84-892473a01 <~~ this harness is an 8 hole female harness that receives the 8 male prongs from the ignition/choke assy so it can plug in to your engine
 

Buster_boy

Petty Officer 2nd Class
Joined
Aug 9, 2015
Messages
178
Yes - it's actually OR014E559 so it looks like it's newer than what you listed. I'm using it now as a kicker to the Johnson. I'm using Quicksilver side mount controls/ignition for the Merc. If I can find a Merc top mount, can I strip the side mount apart and use those parts (throttle/shift cables and electrical).
 
Top