Merc120 to Merc140 Swap

I just bought a 19 foot 85 Starcraft Islander with a Mercruiser120 and outdrive. The boat has been very well maintained mechanically. I also have a 17 1/2 foot 88 Chriscraft with a Mercruiser140 and outdrive that I bought last year.

The Chriscraft was bought from a widow that said it had been on the lake less then 10 times. I took it to my mechanic and he rebuilt the carb and serviced the outdrive. and said it was in excellent condition.

I plan to sell the Chriscraft but wanted to know if the 140 can be easily swapped out with the 120? I would swap both the motor and outdrive. This would give me an extra 20hp. Any recommendations are appreciated.

Re: Merc120 to Merc140 Swap

no need to swap outdrives, they are functionally the same.
seeing as both motors are pre-1990, it will just about be the easiest swap in history

and it makes total sense... your engines are backwards...

a 17 footer with a 120 is still sellable...

Re: Merc120 to Merc140 Swap

Is switching the outdrives that much additional work?

Thanks

Re: Merc120 to Merc140 Swap

Is switching the outdrives that much additional work?

Click to expand...

Nope,.... Everything about those drivelines, from belt to prop should be plug, 'n play swaps...
And,... It ain't really Extra work,...
Ya gotta pull the drive before the motor,+ reinstall the drive after the motor's been aligned...

Re: Merc120 to Merc140 Swap

My mechanic got back to me and said it would be $1000 to swap both motors and outdrives between the two boats. I will have to sleep on that.

Re: Merc120 to Merc140 Swap

Just go rent a cherry picker for a day. Only takes a couple of hours to do. Only 4 bolts hold the engine in place. undo your wiring harness and unhook the water inlet hose. 1st thing to do is undo the trim cylinders on the outdrive and remove the 6 bolts that hold it on and remove the outdrive.

Re: Merc120 to Merc140 Swap

Also, make sure it is in gear when you go to remove it. Mine caught up on me until I read a bit and found out it had to be in gear to remove it. Then it slid right out.

Re: Merc120 to Merc140 Swap

Thanks for all the replies everyone. The problem with lifting it out is the height of the Starcraft boat. I am in the process of finding someone that has a lift or a way to get enough lift height to get it out. Some have used a tractor. The transom mount bolts are in the front but I do not see any in the back. After removing the outdrive, what keeps the back of the motor supported? Also, I have read there is some kind of template to ensure the motor is lined up with the outdrive.

The $1000 is cost prohibitive. However, I know this can't be that difficult and it would be nice to have a fresh motor and outdrive. The prop barely has all the paint off it. Can someone post the link for the mercruiser maual for this model. Thanks again.

Re: Merc120 to Merc140 Swap

Thanks also for the in gear comment. I forgot about that. Also I may not have looked closely for the transom mount towards the rear of the boat. It was dark out.

Re: Merc120 to Merc140 Swap

Zbad,

I pulled the 140 out of my boat with a forklift. Know anybody with a warehouse? Just about any forklift should have the height to get the engine over the transom. Another suggestion if you have something to use as a beam is to use two lifts, one on each side. Lift the engine, and pull the boat out from under it.

Good luck!
Paul