just thought i would share result...of 20ft pontoon with 20hp engine 7p 3 blade prop

[ONERCBOATER]

20 ft tracker pontoon, 20hp 1978 merc 7p 3 blade= 5500-5600 rpm and about 12 mph.
now i doubt that most would consider this sufficient power, but it easily pushed me against a 19mph wind, and though slow, was remarkably efficient at 3500-4000 rpm. You also have to consider that there is a 10ft cabin on the boat, 4 240lb people and a 3 yr old (39lbs) 4 deepcycle batteries, 3 coolers. The reason I even bothered posting this is that i have heard people repeatedly point out it isn't enough power... the actual answer is depends on how fast you want to go, how frugal do you want to be.
Hope this helps someone with a marginal budget who simply wants to put about without worrying about a large gas bill.

Sean

 

[steelespike]

Re: just thought i would share result...of 20ft pontoon with 20hp engine 7p 3 blade p

Thanks for the update.It's allways nice to have some numbers from those applications less traveled.Actually at 3500-4000 your probably running at the top of displacement speed which is ideal for the pontoons displacement hull.If you attempted to run most planing hulls at that speed
most pontoons would do better.Only worries of that little motor would be winds,tide and current especially in some combination.Many people don't have the patience to run at displacement speed
even on a toon thus the need for more power.Especially if you want speed yet to be able to reduce throttle to save wear and tear on a motor thats required to push such an awkward boat that the pontoon is.You have it just right for your needs.
I love the idea of a little cabin on a little pontoon.Do you have any pics? You'll have to post them elsewhere with the address posted here There is probably a sticky with instructions somewhere.

 

[Navigator_Victory]

Re: just thought i would share result...of 20ft pontoon with 20hp engine 7p 3 blade p

I want to see the cabin also...