motor swap ?

[rmr1000]

i have a 2000 suntracker pontoon that currently has a four stroke mercury 40hp big foot motor.im thinking on changing it out with a 1997 mercury force 75 hp motor.what do you think about the swap? would it be worth it to change motors ?im looking for more power i know the 75 is a two stroke and weights alittle less <about 30lbs> im going to keep the 40 for future sale of boat but it only goes about 15mph on lake with 2 couples and two kids.wanting to pull a tube and the current motor does not have the power.looking for advise.thanks in advance

 

[sullmate]

Re: motor swap ?

If the pontoon is 20 ft or less, you should pick up about 5 mph in speed. My family has a 20 ft crest pontoon with a 75 hp e tec and does about 22 mph. I am not a big fan of Force engines, but I like two strokes in general.
Good luck.

 

[Frank Acampora]

Re: motor swap ?

The Force engine comes equipped with a 10 inch diameter prop--not really good for pontoon work. You may be able to buy a larger diameter(Mercury) prop that will help. The gearbox is almost the same as the Mercury 40 and 50 and will take the same props. But I think because of gearing and bigfoot propping on your 40, you may be disappointed in performance. Mind you: There is nothing wrong with the Force and the first one I rebuilt did pleasantly surprise me with its performance, but that was on a fishing boat, not a displacement 'toon.

Before you buy the Force, you really need to investigate what props are available for it.

 

[jerryjerry05]

Re: motor swap ?

How long is the boat?
6 people and stuff(coolers,ice,tackle)is expecting a lot from a 40.
You sure your motor is running right?
RPM's at WOT?2 people and fuel and stuff?Go for a ride and see what the rpm's are.
Nothing wrong with Forces.

 

[rmr1000]

Re: motor swap ?

sorry the boat is 18' 2000 suntracker party bardge.the motor im looking at is 97 force 75,what should compression be on a good motor?

 

[rmr1000]

Re: motor swap ?

the boat is a 18' party bardge.the mtor is 97 force 75 ,what should compression be on a good motor

 

[Frank Acampora]

Re: motor swap ?

I don't have the specs on that engine but generally, the larger Force engines run about 145-155 new. Anything over 120 would be acceptable. However, it is the difference between cylinders, not total PSI that counts. More than 10-15 psi difference is reason to be suspicious.