Prop selection help

[JP423956]

Hey guys it's been a while since I have posted (so long in fact that I had to fire up a new account).
Recently switched to a 1998 150 merc from a 115 on my 1998 20' Trophy. Yah no idea why it had a 115 on it.
First test run on flat conditions with as light of a load I would ever run. WOT 6,000 rpm. Crazy proposing too. Max is 5,600 for this motor. Prop is stock 14.5x17p aluminum.
So I figured I could do a 4 blade 19p aluminum Turning Point. With another 350 pounds on board and the 4 blade 19 i could only hit 5,000 rpm. That didn't really add up to me but hey i was wrong once. So i got a 3 blade 19p Turning Point aluminum and i hit 5,600 on the nose loaded but i don't like the performance. Just feels off. Hole shot not great and seems to lose bite easily in the rough stuff. Looking for a 3 blade stainless suggestion without the pressed hub. Something I can get used pretty easily. Our local fishery is a CF right now and cant justify new with 7 months between seasons. Any help with this much appreciated.
JP

 

[QBhoy]

Tempest plus or enertia. Tempest easier to get a hold of used. Both incredible props.

 

[Scott Danforth]

With another 350 pounds on board and the 4 blade 19 i could only hit 5,000 rpm.

whats so hard to understand. you went up 2" in pitch, 1 blade and added 350#.

the 4th blade adds a fair amount, the 2" pitch adds a fair amount and the 350# adds a fair amount

go down to a 3-blade 19p or a 4 blade 17p

 

[JP423956]

Grumpy guy, I don't see any calculations in your less than welcoming back to I boats response but I do agree with your blade and pitch suggestions. Looking for that and some brand/ style as well. I know some are cupped and other features. Thank you Qb for your suggestions. Seems like the pros of the Enertia are what I need but worried if I went to a 19, with that specific prop if it will be too much load. Hate to find out like I have been so far in my quest.

 

[QBhoy]

Grumpy guy, I don't see any calculations in your less than welcoming back to I boats response but I do agree with your blade and pitch suggestions. Looking for that and some brand/ style as well. I know some are cupped and other features. Thank you Qb for your suggestions. Seems like the pros of the Enertia are what I need but worried if I went to a 19, with that specific prop if it will be too much load. Hate to find out like I have been so far in my quest.

It’s usually an unknown going 4 to 3 blade. The tempest is another prop that can behave a little off too. I know recently when propping a boat for a friend a 19” tempest actually dropped the rpm from the previous fitted 21” 4 blade spitfire ally.
I also know that on my outboard boat, there is a difference of about 100/120 rpm between a 20” enertia and a 19” tempest. Enertia are great things for many reasons. Mainly because there likely isn’t a better all round off the shelf prop...but also because they come in 1” increments for dialling it in so well to suit.

 

[Scott Danforth]

you dont need calculations, its common sense.

 

[JP423956]

Qb thank you. Sounds like the Tempest would be a tough one to nail down without testing at least three pitches and that that won't work in my situation.
Did the 19 tempest have lower top rpm than the 20 enercia? I think that's what you meant but making sure it was not the other way around.

 

[QBhoy]

Qb thank you. Sounds like the Tempest would be a tough one to nail down without testing at least three pitches and that that won't work in my situation.
Did the 19 tempest have lower top rpm than the 20 enercia? I think that's what you meant but making sure it was not the other way around.

No. Tempest 19 had more rpm than a 20” enertia. By about 100/120 rpm. But lower rpm than a 21” aluminium 4 blade spitfire.

 

[JP423956]

Ok this is helping. I should plan on the heavier load outings and I think a modern design merc 17p is my best option. Really need something that keeps its bite when working thru the rough stuff but still have top end improvement over my current.
Much appreciate the info!

 

[JP423956]

Merry Christmas guys. Have a few questions about hubs and prop models.
Currently looking at 73980 quicksilver and 16314 mercury. I know what the mercury version is but what is the quicksilver model?
Also al ot of what I am seeing appear to have pressed hubs. Is it possible to press them out and replace with a flo torq? I have access to a 20 ton.
Any help will help!

 

[Texasmark]

Flow torque has a square receiver cast into the hub. Rubber hub I assume is round as the rubber hub is designed to slip upon striking an object of sufficient size and upon the operator reducing the RPMs to idle, shifting into N, then back to F and accelerating, it will reseat and you be on your way. The other thing about pressed in hubs is that they are pretty much vibration free and being rubber, the F-R gear engagement is pretty much"clunk" free assuming RPMs are within recommended specs.

My experience with half a dozen replaceable hub props of different brands, is that a good whack and your prop thrust is history. Other thing is I read about rattling caused by a sloppy fit of the plastic/brass hub to the SS casting. I understand that Flowtorque brand has made strides to solve these problems and I have a few of them and agree pretty much, but having fished Rip Rap on the windward side (where the fish feed) with older engines that had "shear pins" (not drive pins, "shear" pins......) when you needed drive power the most....wind blowing you on the rocks, you'd accidentally hit a rock and wham....there goes your propulsion.

 

[JP423956]

Thanks Texas. Yes that makes sense about pressed hub style being around and must be replaced with same. If I buy an older version I will first find the hub and get that swapped out before finding out the hard way that it was one hole shot away from breaking free. I do like the vibration absorbing of the pressed hub so maybe just keep my current aluminum with torq as backup.
Anybody have any 411 on the two props I was asking about? The 48-16314 is the Vengeance but don't know what the other one is.

 

[QBhoy]

Thanks Texas. Yes that makes sense about pressed hub style being around and must be replaced with same. If I buy an older version I will first find the hub and get that swapped out before finding out the hard way that it was one hole shot away from breaking free. I do like the vibration absorbing of the pressed hub so maybe just keep my current aluminum with torq as backup.
Anybody have any 411 on the two props I was asking about? The 48-16314 is the Vengeance but don't know what the other one is.

Please...please...forget the vengeance all together. Total hate of mine. It’s just a decorative shiny version of a standard ally prop. Except not even as good as the standard slot black max.

 

[JP423956]

Ha! Is that why there so many used ones available on the interweb? That's good to know.

 

[QBhoy]

Ha! Is that why there so many used ones available on the interweb? That's good to know.

Probably. Just a shiny black max really. Except the black max has been quicker on any boat I’ve known, in comparison. Pitch for pitch, with a vengeance. Waste of money. Nothing fancy to them at all. It’s the entry prop to the stainless market from merc.

 

[catman977]

Hi to all and a Great New Boating Year. I have a Question about a possible Prop Problem. Last season boating up the Missouri River, I experienced a strange, loud thump noise, that sounded like, I hit a large log or something in the current going WOT. I stopped and raised the motor and not seeing anything. I resumed my speed upstream. After a few minutes it happened again. I continued cautiously, at 3/4 throttle and pulled the boat out for the season, not knowing what the problem is.
My boat is a 1990 20' Sun Dancer Pontoon, with a 70 HP 3 Cylinder Evinrude. Prop is a 175013 Stainless Steel. 3 Blade. Would this be a pressed rubber hub problem? I'm assuming this was a complete package, matching the prop with the Boat size and HP. First time experiencing any prop problems!! Thanks To all.