Thread Tools Search this Thread
Old 03 July 2014, 08:35   #1
Country: UK - N Ireland
Boat name: *
Make: replacement soon!
Length: no boat
Join Date: Jul 2010
Posts: 141
Merc engine swap electrics

Hi all

I am swapping a carburetted mercury 90 hp 4 Stroke (year 2000 model) and a 90 hp 2 stroke (year 2002) from one boat to another. One is in an older speed boat with a side mounted control box which includes the ignition switch/fast idle lever etc.

The other boat is a little more modern with the newer control box with the ignition switch is on the dash.

Can anyone advise if the complete wiring harness has to be transferred with each engine.


DJS is offline   Reply With Quote
Old 03 July 2014, 13:57   #2
Country: UK - England
Town: Hoxne
Boat name: Southern Comfort
Make: NorthCraft 5.5
Length: 5m +
Engine: 150 Optimax
MMSI: 235033276
Join Date: Nov 2005
Posts: 122
Send a message via MSN to Under the Thumb
I cant say for sure, but we have the manuals for both those engines as pdf's here, you can compare the wiring diagrams to check

Boating Resources

it will be the in the complete Yamaha. Mercury. Mariner manual 1995 to 2004 book, bottom of the page.


Northern Exposure Rescue

Marine Safety / Photography / Event Management
Under the Thumb is offline   Reply With Quote
Old 04 July 2014, 18:49   #3
Country: UK - Scotland
Boat name: Wildheart
Make: Humber/Delta Seasafe
Length: 5m +
Engine: Merc 60 Clamshell
MMSI: 235068449
Join Date: Apr 2007
Posts: 4,538
FWIW I have my Merc running to Yam 703 electrics mounted in my console.

The big hassle I had on engine swap was the multi plug connection in the engine.

If they are both Mercs you might be lucky.....but I don't have a manual to hand...
9D280 is offline   Reply With Quote
Old 04 July 2014, 23:58   #4
RIBnet admin team
Nos4r2's Avatar
Country: UK - England
Town: The wilds of Wiltshire
Boat name: WhiteNoise/Dominator
Make: Ballistic 7.8/SR5.4
Length: 7m +
Engine: Opti 225/Yam 85
MMSI: 235090687/235055163
Join Date: Jul 2005
Posts: 12,548
If the main loom plug on the motor is the same, they'll swap almost straight over depending on gauges.
Need spares,consoles,consumables,hire,training or even a new boat?

Please click HERE and HERE and support our Trade Members.

Join up as a Trade member or Supporter HERE
Nos4r2 is offline   Reply With Quote
Old 06 July 2014, 13:09   #5
Country: UK - N Ireland
Boat name: *
Make: replacement soon!
Length: no boat
Join Date: Jul 2010
Posts: 141
Had a good look at the connector block on each engine and both are 8 pin with the same configuration.

Thanks for the help folks and the signpost to the wiring manuals etc, its a great resource.

DJS is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 07:15.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.