Prop for our Pontoon

[coalminerswife]

We bought a 1988 Lowe pontoon with a 70 hp Nissan motor, which has been a real pain in the backside, about six weeks ago.

What do you all think would be the correct size prop for this? The first one seemed to be too large, but our new one seems too small?

Here is a photo of the boat, if that will help you in any way.

 

[cc350]

Re: Prop for our Pontoon

Well need more info. What size was the one to big? The one to small size? And what are you looking for (speed? cruising? tubing?) What is the main reason the props are not working for you?

 

[coalminerswife]

Re: Prop for our Pontoon

The one that is on it now is 11/11. It just doesn't give us any speed. We don't need to fly, of course, but right now, we're just poking along.

 

[lncoop]

Re: Prop for our Pontoon

There are many things to consider when propping a boat, especially a pontoon. Here's what we need to know before anyone can help. First, you need to tell us what your max RPMs are supposed to be at WOT. Your manual should have that info, but if you don't have a manual you should be able to find it online. Second, you need to tell us what RPMs you currently get at WOT. If you don't have a tachometer to give you that reading you can add one without spending too much. The prop you need is the one that gets you to the max RPMs at WOT. Once you find that prop you can start experimenting with things like blade size, cupping, number of blades, etc. However, before you start playing the prop game, which can quickly become frustrating and expensive, eliminate as possibilities all other factors that can adversely affect the performance of your barge, such as, water in the toons, algae and other types of crud on the toons, engine issues, and motor height to name a few. Only after you've addressed any of these issues that need addressing and still don't have the performance you should will it be time to start experimenting with props. When you get time, do some perusing of the Pontoon section for some really good additional info. Good luck.

 

[steelespike]

Re: Prop for our Pontoon

Ufortunately you seem to have the small gearcase but should be able to get some speed. Speed probably would be 18-22 mph. please tell us the prop sizes and the max wot rpm and speed with each.

 

[coalminerswife]

Re: Prop for our Pontoon

Thanks, guys. We solved our problem. We bought this pontoon earlier in the summer. It had been sitting, though, unused, since 2006. So, it took a little time to work out the kinks. The problem was not the propeller, like my brother-in-law thought, but rather that the carburetors were all gunked up. My husband cleaned them, and then put the original prop back on. Now, as he likes to say, it runs "like a scalded dog."