Thinking about going bigger..75HP to 140HP

[BigPoppie]

I have a 1990 Sylvan 24ft pontoon with a 1975 Johnson "Stinger" on it currently. This motor runs great but doesn't have trim and I have been thinking about getting something bigger if I found the right deal.

Today I came across a 1987 Evinrude 140 HP 20" shaft with trim right on throttle controls for $800.

My pontoon says max HP is 125. I believe this motor is the same weight as 120-125hp with larger carbs but don't have any real experience and would like to know what the possible issues could be or anything that I am not thinking of because I am drewling with the thought of the perfect fit...

Thanks in Advance!!

 

[The Rooster]

Re: Thinking about going bigger..75HP to 140HP

I believe you're right about those Johnnyrude 120-140 motors being the same weight. On a 23 yr. old pontoon, I'd think about some additional bracing or bolts for the motor pod for some peace of mind. It's generally not a good idea to exceed the hp rating of the capacity plate, but it happens all the time. Just remember the possible insurance and liability issues should something go wrong. Good luck !!!

 

[5150abf]

Re: Thinking about going bigger..75HP to 140HP

the rating has little or nothing to do with weight, the hang weight is insignifacagant compared to full throttle torque.

an engine is essentially a giant lever attached at the top with force applied at the bottom, the torque is what is rated.

and it won't work right out of the gate being a 20'' engine, pontoons almost always have 25'' engines so it would cavitate like mad at any kind of throttle unless you lowered or alter the motor pan.

so found a good deal on an engine but i don't think it will work on your boat.

sorry no caps, broke my arm and i am left haded for a bit.

 

[BigPoppie]

Re: Thinking about going bigger..75HP to 140HP

Do you or anyone else viewing this know if there is a required length of shaft needed for a pontoon boat like this? This motor has a 20" shaft and I am just trying to make sure that it will be a match for this pontoon. Is there any way to research this or am I overt hinking this?

 

[BigPoppie]

Re: Thinking about going bigger..75HP to 140HP

I sent this before I saw your reply. Thanks!!