Pontoon Boat & Deck Boat Forum

Good morning and hello to all. Looks like a great site. Many years boating for the wife and I,however we know nothing about pontoon boats. Been reading here for a couple of days and learned a lot. Went out on a couple over the weekend and the wife fell in love with the ride. Kids and grandkids grown and gone,so no one to pull on a tube but each other ( not happening ) in other words speed is not a factor,been there done that.

As i said,wife fell in love. Should everything go right,this coming weekend we will be picking up a ,new to us, 1998 22 ft Sweetwater with changing room,sink,yada,yada . This boat has a 70HP Yamaha with a year warranty on it. The motor is a two stroke and my plea for help is with prop size. Part of the deal is a new prop,my insistence, but I need some guidance with size. Can anyone help ?






JD

JD,

it all depends on what your RPM's are at Wide Open Throttle (WOT) You need to run it before deciding on size of prop.

Looks like it should be running between 5 and 6 K. Find out what your rpm's are now and we can help.

and welcome.

Don't forget pics!!!

Welcome to the party. We need the above mentioned info before picking a prop. You'll have to run it to see where you're at.

Welcome to the party!
Is the lake you are going to toon on rocky with tree stumps? If so then I would recommend a stainless steel prop. Hit a rock with an alum prop and it is done. Use the aluminum prop as a spare.
Like was said above, run it and then let us know the rpms.

Wow. Fast replies,many thanks everyone. When we were out the motor was running right at 4000 R.P.M. wot. I know that is not where it should be. I forgot to try to trim it with my wife getting so excited about the boat. Like I said,no knowledge of pontoon boats. Would trimming the motor on a toon raise the R.P.M.'s that much ?

JD

We owned a 21 Sweetwater with a 60hp 4 stroke Yamaha and it had a 14 x 11 prop on it, factory installed.
It was the correct prop for that boat.
Call a Sweetwater dealer and ask them what they use.Our boat ran 21mph with the 60 so you should do better.

Hey Texoma,love your sig.

Rock's and stumps. Well I am in lake Wallenpaupack a man made lake that runs 60 to 70 feet deep. Made over a flooded town with most tree's at the bottom same with the rocks. There are several small islands that are really the peaks of hills. Lots of rocks there.
This is my first time and first year in a lake. All river,bay and ocean up till this year,so it's all new to me. Really looking forward to the pontoon boat.

JD

Thanks Gramps. Good idea will give it a shot.

JD

Welcome aboard the nuthouse,JD!

Congrats on the new boat.
1. Find out what the engine is suppose to run at based on manf. specs at WOT.
2. Then have the engine checked to make sure it is running at optimum performance.
3. Then run boat and see where it is at WOT.

Number two is very important. I went through the whole process skipping step two, only to find out that both my fuel filters were very clogged. When I fixed this I got 400 more rpm's than before. The engine I bought was used, but as yours still had 1 year left in warranty and was supposedly just serviced before I bought it.

As for stainless prop IMHO, I would not waste the money. As long as you know the boating area, and are careful, you will have no problems. Rocks damage stainless as well as aluminum, but more importantly they damage other parts as well due to the rigidity of the stainless prop. On a smaller hp motor 125 or less it is not needed.

I'm on a rock bottom lake/river. I used to go thru an aluminum prop a year on my inboard outboard boat, but switched to a stainless prop when I got a new boat. It lasted 12 years before I blew the motor without any bent props.

That said: I'd probably go aluminum on an older boat, or if the boat was 115 hp or less.

If you're having prop issues, look for a good prop shop. Buy from them and their expertise and advice is free. They're usually no more expensive than buying from the local boat dealership.

I don't know anyone who runs an aluminum prop here. This place is 2 miles wide and a foot deep. You won't last a week with an aluminum prop before you get a ding. After a while it gets so dinged up your performance falls off to an unacceptable level.