115 Pro XS Command Thrust on a pontoon - prop?

[jlh3rd]

ok..I'll take a pic tomorrow....there was a plastic insert that Turning Point provided and said needed to be placed between the prop and hub....but the prop hub diameter isn't smaller than the gear case diameter ...but
...now you have me doubtng....i have to check...

 

[jlh3rd]

That’s interesting. From everything I read, all CT gearcases have a larger torpedo and take larger diameter propellers (4.75”), the same as the higher HP outboards. This allows for more prop selection as well. You can’t run a 4.25” propeller on it because the exhaust will just blow over the prop causing extreme ventilation (ask me how I know). It will fit on the gear case fine, but there will be a gap for the exhaust to blow out. Do you have a part number for that Hustler prop?

here..
but wait until I go check tomorrow......I'll measure the spitfire, the husler..and the hub ...plus pics.....Hope your wrong

 

[jlh3rd]

Ct does have the large gearcase. So needs to run the props that suit it. It’s the same size props that usually fit the Mercury engines of 150hp and above. Also the same as the mercruiser alpha and bravo 1 outdrives.

uh oh....for me....

 

[dcwilson]

ok..I'll take a pic tomorrow....there was a plastic insert that Turning Point provided and said needed to be placed between the prop and hub....but the prop hub diameter isn't smaller than the gear case diameter ...but
...now you have me doubtng....i have to check...

Yes there is a plastic bore sleeve that has to be put in before the prop to prevent the exhaust gases from escaping around the prop. It a flimsy thing that breaks off all the time. My gearcase was missing it when I got my boat which caused terrible ventilation even with the right size prop, took me awhile to figure out the problem and it stumps a lot of people if you read online. Its a thin piece that basically rests right to the front of the prop. I thought maybe you could get a bigger sleeve to accommodate smaller hub props but that is not the case.

here..
but wait until I go check tomorrow......I'll measure the spitfire, the husler..and the hub ...plus pics.....Hope your wrong

Yeah I am curious to see, even on BoatID that you posted I can't get that prop to come up in anything other than 4.25 hub.

 

[jlh3rd]

ok.......anyone need an unused Hustler 4blade, 14x13, 4.25 hub?...lol
pics in order...Spitfire(supplied)...hustler ........and where my cavitation plate is in relation to the center transom support.....
comments? ...that hustler isn't gonna work, right?

 

[jlh3rd]

Yes there is a plastic bore sleeve that has to be put in before the prop to prevent the exhaust gases from escaping around the prop. It a flimsy thing that breaks off all the time. My gearcase was missing it when I got my boat which caused terrible ventilation even with the right size prop, took me awhile to figure out the problem and it stumps a lot of people if you read online. Its a thin piece that basically rests right to the front of the prop. I thought maybe you could get a bigger sleeve to accommodate smaller hub props but that is not the case.


Yeah I am curious to see, even on BoatID that you posted I can't get that prop to come up in anything other than 4.25 hub.

it appears that im going to need a black max, 3 blade, 16x13.. with the 4.75 hub...to get the rpm's I want...maybe the route we have to go....3 blades, not 4....to get that 4.75 hub match...
it now seems these smaller CT motors...with big pontoon boats can be difficult to prop...of course....

 

[dcwilson]

ok.......anyone need an unused Hustler 4blade, 14x13, 4.25 hub?...lol
pics in order...Spitfire(supplied)...hustler ........and where my cavitation plate is in relation to the center transom support.....
comments? ...that hustler isn't gonna work, right?

Thanks for posting your engine pod in relation to your cavitation plate, very helpful. Yeah that hustler isn't going to work. My boat came with an extra prop which was a Spitfire 13.8X13 4.25". Well I tossed it on and took it for a spin one day before I knew anything about outboards. Got a whole 5mph at max rpm lol. Exhaust just blows right over the prop.

I think I'm going to still stick with the Spitfire 14X14 4 blade. The 4 blade helps with lift and maneuverability with a pontoon. Not perfect RPMS but there's not really any other option for a 4 blade.

 

[jlh3rd]

I had the exact experience with the same 13.8x13 prop!....couldn't figure it out...until these posts.....learned something new..
Went to the merc dealer...so...fyi...There is a spitfire, 4 blade, 14x12, 4.75 hub.....If this 16x13, 3blade black max doesn't work.....I'll just get that....
Yep, that motor cav. plate position solved my blowout problem.....
I lost about 1mph....but I can turn at full throttle and almost throw you out of the boat...It hooks up ...didn't do that before.

 

[dcwilson]

I had the exact experience with the same 13.8x13 prop!....couldn't figure it out...until these posts.....learned something new..
Went to the merc dealer...so...fyi...There is a spitfire, 4 blade, 14x12, 4.75 hub.....If this 16x13, 3blade black max doesn't work.....I'll just get that....
Yep, that motor cav. plate position solved my blowout problem.....
I lost about 1mph....but I can turn at full throttle and almost throw you out of the boat...It hooks up ...didn't do that before.

Yeah I did look at the 14X12 spitfire but I'm concerned it wouldn't be the best performance as using a prop slip calculator it's max speed at 6000 rpm would be 28mph with a 2% slip and may over rev possibly. At least with the 14X14 you can be around 5700 at 27ish mph. Ideally if a 14X13 4 blade large hub prop existed, I think that would be the ticket.

 

[QBhoy]

Yeah I did look at the 14X12 spitfire but I'm concerned it wouldn't be the best performance as using a prop slip calculator it's max speed at 6000 rpm would be 28mph with a 2% slip and may over rev possibly. At least with the 14X14 you can be around 5700 at 27ish mph. Ideally if a 14X13 4 blade large hub prop existed, I think that would be the ticket.

I’d also add that you almost certainly won’t see anything like 2% slip on that rig either.

 

[jlh3rd]

yep...a14x13, 4blade, 4.75 hub would be the ticket,...figures there isn't one.....
the 14x12 would take me over max rpm when it's just me...but loaded down might be ok, use the tach......if this 16x13 doesn't work...I'll just get that...
I'm just glad I now know about gearcase size....the 16x13 gets here tomorrow.....late april I will know....

 

[jlh3rd]

ok....got out on the river today. It was windy and a little rough. But I saw 27 mph and 6000 rpm. with the black max, 3 blade, 16x13...I think I'm where I want to be. I did not have the full bimini up..so there's that....I don't think the spitfire, 4 blade, 14x12 would be better......

 

[QBhoy]

That’s probably an outstanding result. Only 13% prop slip from a pontoon and an ally prop. Amazing. Well done.

 

[jlh3rd]

yeah, well....thanks to people on here ...

 

[Texasmark]

The "bright idea" of the day: Put a jack plate on it and tweak it till it suits you.

 

[QBhoy]

I’d be tempted to get a good stainless on there the same pitch. Just for getting as good as it gets

 

[Texasmark]

I’d also add that you almost certainly won’t see anything like 2% slip on that rig either.

Hard to get 2% on anything. My guess would be more like 20%. Reason why is too much of the surface that would otherwise ride ON the water is IN the water.

 

[jlh3rd]

The "bright idea" of the day: Put a jack plate on it and tweak it till it suits you.

eh...don't need to spend that time and money for minimal performance gain....it's a pontoon...

 

[jlh3rd]

I’d be tempted to get a good stainless on there the same pitch. Just for getting as good as it gets

yeah...I mostly run in the susquehanna river in pa....fairly rocky....I kinda know where to run, and haven't hit anything in years....but just didn't want to take that chance....

 

[QBhoy]

yeah...I mostly run in the susquehanna river in pa....fairly rocky....I kinda know where to run, and haven't hit anything in years....but just didn't want to take that chance....

Completely up to you of course…but I’d suspect that most times, you’d be better off with a stainless. The old wives tale of a stainless damaging gearboxes, if you contacted the ground, isn’t terribly accurate these days. That’s a throw back to when stainless props were hard splined onto the shaft. These days you’re off the shelf stainless prop and much any other prop is fitted using a sacrificial hub, as you’ll likely know.