big foot 50 is it worth it??..

hamburgerman

Petty Officer 2nd Class
Joined
Apr 17, 2006
Messages
102
OK we have a 19foot pontoon weighs 2500 full gas and 2 passengers
50 4 stroke big foot
wot.5800 sometimes runs 6000
prop 14x10p
speed gps 15.5/ 16 at best

if i get more passengers or pull a tube it slows considerably,although i do not see any bogging down still at 5800 wot
its like the power seams to be there to go up in pitch and maybe gain a bit more speed (most of the time its just me and a few gallons of gas so not worried about improving tubing )
cav plate is top and i trim it straight out and catch air if i mess with it up or down too much. maybe time to prop test any input before i start spending is welcome .... thanks in advance!
 

ahicks

Captain
Joined
Sep 16, 2013
Messages
3,957
You're pretty close it sounds like. Anything you gain on top is going to be taken from the bottom, so that's your call as you balance your wants/needs to come up with a compromise in your quest for YOUR perfect prop. You're not going to gain much in speed no matter how you prop it, another couple mph at max, but you stand to just kill low speed performance. A prop guru familiar with your boat might be worth seeking out - the kind of guy working at a good prop repair shop....
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,296
even if you pulled the 50hp and installed a 90hp you wont gain much speed.
 

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,286
Do you mean just changing the lower drive gearbox for a big foot ? Or getting a whole new engine big foot ? If the latter, why not just get a bigger engine ?
 

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,286
Apologies...just read your post again..yeah...big foots aren't really ideal for anything other than punching above their weight for the horse power. Their down side is that they aren't great for much else once up on the plane and running. They are all about low horse power and pushing heavy boats beyond the capability of a equal horse power engine.
 

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
12,944
You have two things working against you, 1) A big boat for a 50hp, 2) a 4 stroke to boot
 

hamburgerman

Petty Officer 2nd Class
Joined
Apr 17, 2006
Messages
102
i wandered cause i see boats like mine with a family of 5 or 6 and a 40 hp blowing by at 5 mph faster .. It does get up go out of the hole real fast ... i would trade that for a few mph as long as my wot is still with in specs ....Peace!
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
About the only thing you can do is try going up one step in pitch (not sure what prop's there are for it) and see if you like it.
 
Last edited:

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,286
Yeah...the big foot models ain't made for speed. They have their place and application though and should be admired for it....just not for going fast....bottom line.
As Jimbo rightly points out....she is a 4stroke too...adds to the misery, in my view.
 

ahicks

Captain
Joined
Sep 16, 2013
Messages
3,957
The "Bigfoot" option is about a lower unit that's also used on engines twice this size. That's done not for just a super durable lower unit, it's done so it can swing much larger diameter props than more conventional engines. In this case, where you are looking for speed, that large diameter diameter prop isn't helping your cause at all. It's more at home making big thrust while maneuvering around docks or possibly pulling a tube.

As far as being a 4 stroke, I would think this engine should provide comparable performance, even if it might be down just a hair. The bonus is the fact it will putt around silently without protesting - or using much fuel.

As far as props, our 20' Sweetwater, with a Honda 50 on it, will hit 18-19mph when lightly loaded, going down hill with a tail wind. ;^)

Your engine is turning a lot of rpms with the prop you have. If you aren't all that concerned about trying to tube behind it, I'd go up one size for sure. You'll lower your cruise rpm, use a little less fuel (a non event for your engine) and maybe pick up a couple miles an hour. Don't get anything fancy, you just can't justify the extra expense. An OEM prop would be fine.
 
Top