pontoon hp

[xlthompson]

I have a 1968 ,28 foot pontoon that has a 55 hp Evinrude motor on it. We run the boat at about 3/4 open throttle most of the time. I was thinking of changing out the motor to one around 85 hp in hopes of running the RPM's slower and then the motor would be quieter. What would be your thoughts on this swap? Would the mileage be that much different given I would be running the 85 slower?

 

[Dunaruna]

Re: pontoon hp

Yes, if propped correctly, you will run at reduced RPMs but you may find too tempting to leave the extra horses tethered in the barn.

I'm guessing that an old 28fter is pretty heavy, have you considered a bigfoot?

 

[tashasdaddy]

Re: pontoon hp

if you want quieter go to an ETEC or 4 cycle. or build a bonnet over the motor to deflect the sound.

 

[steelespike]

Re: pontoon hp

The 55 will use about 5.5 GPH(gallons per hour) at WOT(wide open throttle) probably 3-4 GPH at cruising speed.The 85 will use about 8.5 GPH at WOT
and you could adjust speed to match the the 55s GPH.at about the same speed.The 85 will really be loafing as well saving some wear and tear.If you play with your cruising speed you may find a sweet spot that is most economical.Careful selection of a dedicated pontoon prop will further improve
mileage/rpm and sound.

 

[Jeff Walkowiak]

Re: pontoon hp

I had a 50 hp evinrude that ran great but it was really a loud engine,, never realized how loud it was untill I changed to a 70 hp johnson,, that engine runs way quieter than the 50.. both are 2 stroke engines. no idea why the 70 is quieter, I run it near w o t and it's still half as loud as the 50 was.

 

[xlthompson]

Re: pontoon hp

Thanks for the replies. The 55 has some isues so it sounds like I am think right. Not sure what a Big Foot is can anyone help me out there? I love this site.

 

[jamoke]

Re: pontoon hp

Bigfoot engines are made by Mercury. They are 4-stroke and are sized up to 60 HP. They are called Bigfoot because they have the lower drive unit of a 75/90 sized 4-stroke, will take a larger diameter prop, and the prop will sit lower in the water.

Whatever engine you decide on, be sure you can take the added weight. Simulate the added weight and see how your toon sits in the water.

 

[rrhodes]

Re: pontoon hp

At idle I have to look at the RPM gauge to see if my Honda 4stroke is running.

 

[Dunaruna]

Re: pontoon hp

A bigfoot has a larger (about 1/3 larger) gearcase and internals, it also has a higher gear ratio and a second anti-vent plate. It is designed to turn a larger prop without lugging (although lugging is still a possibility). They are more of a a Clydesdale than a mustang, perfect for heavy houseboats.

 

[chrisg]

Re: pontoon hp

They are more of a a Clydesdale than a mustang, perfect for heavy houseboats.

Sounds to me like someone is a horse lover! Me too, I put whats left of my 401k money into STABLE funds

I just replace my loud old 115 merk with a 60HP bigfoot ( 2-stroke) it is quieter, and from what I see, the cost difference between a 2 and 4-stroke outweighs the fuel/ noise savings.

Gee, must be nice to be playing in the water, After last year, I'm not putting my boats in until July.