Changing motors

RGB4545

Cadet
Joined
Jul 1, 2012
Messages
20
I have 90 HP Force on one boat and 125 HP Force on the other, How much works is entailed to change motors from one boat to the other.:confused:
 

MickLovin

Master Chief Petty Officer
Joined
Feb 18, 2013
Messages
822
Re: Changing motors

Are they the same controls?, if they are mark what your cables are connected on both motors, I am an electrician and I use white electrical tape and a permanant marker when swapping any cables over. It will also depend on the year difference as well I can imagine, but it should be possible. It is definately possible if you swap your controls as well, but I am pretty sure you mean swapping just the motor.Try and google the wiring diagrams, so you know what goes where on both engines before even attempting a change over. As I say I don't know what years or controls you are using, so I am not promising anything, but I can imagine it can be done. Let us know what year each motor is and what controls you are using and I will try and find the wiring diagrams and see if it is easily achievable.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,041
Re: Changing motors

It depends on the year.
What year for both motors?
The older stuff up to I believe 93-4 will just swap.
After 94 the Mercury connectors and controls were used and may cause a problem.
 

calvinator

Petty Officer 1st Class
Joined
Sep 22, 2010
Messages
286
Re: Changing motors

I have been changing motors on my pontoon. Pretty straightforward, but some of my lessons learned:

a) buy a car engine hoist off craigslist. This makes lifting, moving, adjusting the motor easy.
b) Understand how the controls work and how to adjust them between motors. Then you can optimize for best performance.
c) I removed my lower unit for service, and then spent a good 4-5 hours figuring out how shifting works.
 

MickLovin

Master Chief Petty Officer
Joined
Feb 18, 2013
Messages
822
Re: Changing motors

The controls between them could be totally different if the years aren't similar or they have changed between years as jerry jerry stated. Also they could have different colour wiring which you will need to ascertain what does what to be able to change it over.
PO let us know what years they are to resolve your issue.
 

HotTommy

Lieutenant Junior Grade
Joined
Mar 15, 2013
Messages
1,025
Re: Changing motors

IF the two motors have similar connections, it's not too bad a job. I'm in the process of replacing my 1994 Force 90 with a 1993 Force 150. I haven't finished the job, but the connections appear to be the same. My major steps were:
1. Disconnect the battery cables. If the cables on both engines are about the same length, you can just disconnect them at the battery. If they are different lengths, you'll have to disconnect them from the engine to so they can stay with the boat.
2. Disconnect the quick connect fuel lines at the engine. If they use the same fittings, that part is done.
3. Open the window where the cables and connections enter the front of the cowl. On mine there was a small plastic piece that held everything in place. Make notes or take photos so you can remember what went where.
4. Mark the throttle and shifter cables with tape so you can remember which is which. Disconnect the cables from the engine.
5. Disconnect the large electrical cable where it plugs into the engine.
6. Pull all of the above from the engine and stow it out of the way.
7. On my engine I also had two hoses that ran to the boat's instrument panel. One was attached near the thermostat and provided water pressure info. The other came from the lower unit and provided pressure for the speedometer. If you have these, disconnect them. If one boat has such gauges and the other doesn't, you'll need to swap fittings so the hoses can attach to the new engine.
8. Disconnect the steering cable where the inner cable attaches to the arm, and where the outer cable attaches to the engine.
9. Remove the steering cable if you can. On my boat I had to wait until the engine was partially lifted from the transom before there was enough wiggle room to get it out.
10. Attach your lift to support the weight of the engine and remove the transom bolts.
11. Lift the engine from the transom. Keep in mind that you'll need somewhere to rest one engine during the swap. I made a temporary stand out of heavy lumber.
12. Put it all back together in opposite order.

Good luck.
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: Changing motors

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I swap engines more often than I change my underwear. ASSUMING that both engines are the same control system--that is, either both are Mercury or both are US Marine--you can swap engines in about 1 1/2 hours IF you have a lift. Add a couple more hours if you need to change the control systems.

I was not in any hurry so it took me about 2 hours to swap the Force 150 in place of the Chrysler 140. Since the Force was a 20 pole ignition and the Chrysler was a 12 pole distributor ignition, I also needed to replace the tachometer and rewire the ignition switch for about another 1/2 hour.
 
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RGB4545

Cadet
Joined
Jul 1, 2012
Messages
20
Re: Changing motors

Thanks for all the replies guys. But problem solved. I was offered more money than expected for the old boat with the 90 on it so I will not be swapping motors. :):)
 
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