Pontoon Boat & Deck Boat Forum

Well we had a bad day on Memorial day, broke a prop so now I have a new cup holder on my deck. Oh well, thats life.

Prop shop could fix it and I won't even say how a prop guard would have saved the day

I ordered up a new prop, going to try a composite with replaceable blades, should be here this week and try it next weekend. As far as a prop guard goes that would be taking the fun out of it in a river with changing obstacles every spring!!!

Holly crap!!!! You took a chunk out of that prop. I would check the prop shaft and make sure it's not bent. Eye ball the end of the shaft and spin it.

pontoon shine wrote:I ordered up a new prop, going to try a composite with replaceable blades, should be here this week and try it next weekend. As far as a prop guard goes that would be taking the fun out of it in a river with changing obstacles every spring!!!

What brand prop are you switching to? I have been running Pirhana props for the last dozen years on about 5 different boats and those guys treat me like gold. I swap out ears basically for free until I find the pitch I like. Then my spare prop consists of a tiny little bag of ears. I only wacked one rock so far and the lower unit and the hub survived with zero damage. Awesome.

I am getting a Piranha. I read up on them and it seemed that it was the best of the composites. I hope it works as well as they say. My broke prop was a 12.25 x 9 aluminum so the new one will be the same size. My best RPM is about 4800 with that size so maybe I will crank out a bit more with the piranha.

Neal

Shine: Depending on the size of your motor you may want to rethink staying with the same prop size when switching from aluminum to an SS prop. Especially when you’re already running a little low on the rpm's at wot. Aluminum props flatten a little under load on motors pushing more than 90 hp. SS won't flatten at all and give you more pitch than you current aluminum even though they may have the same pitch.

Hey Slingshot, thanks for the input. I run a 50 honda four stroke. Never really been able to get to correct rpm range of 5500-6000. I have tried 6 props and if the piranha does not give me any more rpm then I will get another aluminum with a 8 or 7 pitch. I don't want to run stainless because our river is full of water hazards.
Neal

I have to say it again. The reason S.S. props were made is for hitting stuff, with Alum you destroy the prop. The S.S. props just kicked up the lower unit and you continue to keep going on with your day. Granted that after a few hits like your you might have to have the center re-set as the rubber could have gotten damaged.

Shine: It's your call but your 50 isn't going to gain any performance by going to an SS prop. they cost 3 to 4 times more than a aluminum. Get another aluminum prop but go down in pitch. For every inch in pitch you drop you can expect to gain about 200 rpm's on your wot. you want to hit the engines max rpm with a light load on the boat. It sounds like you have to much pitch in your current prop.

Hey Shine...back from drilling a whole bunch of holes in my tubes.
I disagree with the SS guys. The prop might not break when you hit something, this is true. BUT, all that impact is transmitted to your prop shaft and lower unit then. El Mucho Damagio perchance.

Aluminums are not bad for impacts if you use a rubber hub, BUT if you've ever 'spun' a rubber hub, you are dead in water. At least your motor lives and the hub is rebuild-able.

Pirhanas will ALWAYS let your motor live and are fairly easy to slap new ears on. On top of that, if you have the wrong size (diameter) or pitch of ears, just send them back for FREE (plus shipping). They also have a VERY knowledgeable staff and can help advise on pitches. I bet I have gone through a DOZEN sets of ears in trials over the years. As long as they are undamaged (as composite ears always are), they will trade with you.
Another advantage is that they are always in perfect balance. The only time they are not is when they are broken.
I saw video footage of them purposely running over a log time after time. Some times the ears bent and then snapped right back. Usually they broke. Then they just slapped some new ears on and did it again and again. Never damaged the motor.

pontoon shine wrote:I am getting a Piranha. I read up on them and it seemed that it was the best of the composites. I hope it works as well as they say. My broke prop was a 12.25 x 9 aluminum so the new one will be the same size. My best RPM is about 4800 with that size so maybe I will crank out a bit more with the piranha.

Neal

You must have a throttle cable problem, I have a 30hp on my 18 toon with a 9.75 x 9.5 prop and I can get 5000 rpm, maybe just a smaller Dia prop, going less than 9.5 pitch on a 50hp seems small..

Hello everyone. Couple of things to comment on. First is I had new COMPOSITE prop delivered yesterday, was impressed with the thing as far as workmanship of it. Second thing is a few people somehow seemed to think I was going to use a SS prop. No how or no way did I mention that and would not consider it for the water I run in. The reply that Tuned gave with his positive comments on the composite prop is typical of the information that I found that convinced me to shell out the dollars and try one. Most everyone in the river we run hits something during the season. Hey Timmac, thanks for the suggestion on the cable throttle, been down that road already though. I have tried six new props, replaced tach twice, put in new cables (throttle and shift), synched the carbs after full breakdown and cleaning twice. New plugs, fuel lines, main fuel line from tank, ball on fuel line and still can't get to 5000 rpm. Motor runs like a top, never need to squeeze the ball after it sits a week of no running and she fires off first turn of the key with choke half up. The boat is not overloaded and the tunes are polished. If anyone else has some suggestions I would appreciate them but as of now I think I have gotten the best out of it that I can. I do get 20mph (GPS)out of it with just myself on board so I can't really complain about the speed. Just aggravating to think I should get a little more with some more rpms. I will still consider going 8 pitch if the composite does not work out. Will post results sometime this weekend after installation and test run.
Until then everyone boat safe!!
Neal

If the composite has the same RPM than just replace the blades to a smaller diameter blades 1st, your at 12.25D-9.0P than drop to 11.0D-9.0P, I have read about props and heard from a few that know and 9.0P seems at the low pitch point for a 50hp, my 30hp has a range of 7.0P to 9.0P for pitch on boats this size [pontoons].

By the way I have also ordered the piranha prop yesterday for my boat, going from a 9.75D-9.50P to 10.0D-9.0P, figure I will start here since I don't have a back up prop..

If you go lower on pitch like 7 or 8 you will raise rpm,s but also lower your speed..
[ us low hp pontoon folks don't have speed to spare ]

hey Timmac,
Thanks for the info, bad news is that piranha won't give me a smaller dia for a 9p, they are not available, what is available is shown below for my motor

129C Replacement Blade: 12-1/4 x 9, C-Style 12-1/4 x 9 x 3 (19 - 22) MPH
1211C Replacement Blade: 12 x 11, C-Style 12 x 11 x 3 (23 - 27) MPH
103/813C Replacement Blade: 10-3/8 x 13, C-Style 10-3/8 x 13 x 3 (28 - 32) MPH
111/213C Replacement Blade: 11-1/2 x 13, C-Style 11-1/2 x 13 x 3 (28 - 32) MPH
101/815C Replacement Blade: 10-1/8 x 15, C-Style 10-1/8 x 15 x 3 (32 - 37) MPH
121/415C Replacement Blade: 12-1/4 x 15, C-Style 12-1/4 x 15 x 3 (32 - 37) MPH
113/417C Replacement Blade: 11-3/4 x 17, C-Style 11-3/4 x 17 x 3 (36 - 42) MPH

I think that the 13 pitch is not a good option, tried it in aluminum and was lucky to see 4000 rpm and 15 mph

I guess I am chasing ghosts with all this, did not mention in previous post that I have even raised and lowered motor to help find those rpms.

Neal