Small barrel prop on a large lower unit?

[g352nv]

Im in a pickle because of where I fish. Im fishing out of a 20 ft Basscat jag with a 98 DFI. Motor is solid and ran 70mph when I tested it at sea level. It has a 25p fury on it. So I get it home go fishing 6000 ft elevation andit wouldnt plane until my dad sat on the deck. That was with empty live wells also and a light load.

So I bought a 21p laser2 and its a small barrel. I bolted it on and its all good but theres a gap because of the size difference. Ill be testing Sunday, that said will the size barrel be a issue? Thanks

[Fatshaft Merc]

That's a smaller diameter prop than the fury, thus it will be easier to turn. However, the smaller barrel may let it vent too much and blow out. They make a plastic ring that goes on the prop to fill that gap that you may need if it vents too much.

[21XDC]

That prop will not work well on that combo. It's better suited for smaller, lighter boats with 115 hp and less.

You might consider a 23P Fury3 or Tempest Plus

[g352nv]

That prop will not work well on that combo. It's better suited for smaller, lighter boats with 115 hp and less.

You might consider a 23P Fury3 or Tempest Plus

Thanks for the info. I went to a site where you plug in all your info and elevation and it said 19p. I was llike no way! So I thought maybe the 21 will work.

If it sux Ill try the 23p next, thanks!

[mike464]

My buddy is in the same situation. He's setting up a PII to fish Flaming Gorge. I don't think a 23 Fury is going to get you there, you'll gain 400 rpm over the fury 25. He's trying a 22 Bravo 1XS this weekend. He started with a 25 Fury 4, then tried a 24 Bravo 1 XS and it was still too much prop. He's btribby on here, you two may be able to help each other out.

[g352nv]

My buddy is in the same situation. He's setting up a PII to fish Flaming Gorge. I don't think a 23 Fury is going to get you there, you'll gain 400 rpm over the fury 25. He's trying a 22 Bravo 1XS this weekend. He started with a 25 Fury 4, then tried a 24 Bravo 1 XS and it was still too much prop. He's btribby on here, you two may be able to help each other out.

I don't think many fish this high up. I'll try the 21 on Sunday and see how it goes. I'll keep my 25 for sea level

[21XDC]

I don't think many fish this high up. I'll try the 21 on Sunday and see how it goes. I'll keep my 25 for sea level

My first post, I missed the elevation part... The laser2 is still not the right prop. It's not only about pitch. You need more blade area to lift the hull. 19-21P Tempest Plus would be a better choice.

[g352nv]

My first post, I missed the elevation part... The laser2 is still not the right prop. It's not only about pitch. You need more blade area to lift the hull. 19-21P Tempest Plus would be a better choice.

You think a 4 blade would also help?

[06 SB]

I cannot imagine that small barrel Laser will work. It has small blades, no cup and is kind of a crappy prop when using it for its intended purpose. I would be using a Bravo prop which goes down to 20 pitch.

[21XDC]

You think a 4 blade would also help?

It will help holeshot, But be 1-3 mph slower on top end.

[g352nv]

Ok just a update. Took it out yesterday and ran the 21 laser 2. Jumps up but did have some blowout, Maybe the fact that theres no prop ring and the small barrel? If I start trimming right away I have no issue and shes off and going. Top speed, lol 52mph. But hey at least we got on plane.
21XDC still a 23p tempest plus? Will I need a prop ring? Sorry for all the questions just want to make sure its right before I spend 600.00 lol.

[btribby]

This is going to be a fun/frustrating thread over the next month or so. Like Mike464 mentioned earlier, I am trying to get my PII set up to fish at Flaming Gorge; ~6500 feet of elevation. When I bought the boat it came with a Fury4 25P. I was turning 5100 RPMS at 4500 feet of elevation. I really dont think that the 23P Fury three blade is going to be the answer. Yes, going from four blades to three will increase rpms and speed. But it will kill hole shot. And going from a 25P Fury to a 23P Fury will only benefit you at most 400 RPMS. After a call with Mercury, researching many threads, and chatting with Mike464 and others I decided to go with a Bravo 1 XS 24P which would act like a Fury 22P (Which obviously doesnt exist). The 24P ran at 5450 RPMS at 4500 feet. I then went with a Bravo 1 XS 22P and ran it this weekend at the elevation of 6500 feet. I maxed out at 5350 RPMS. Which means Im still 400 RPMS short. The hole shot has been incredible, which at high elevations is typically is awful. I have a friend who fishes Flaming Gorge regularly and runs a Sabre with a 150. He is running a Tempest 21P and is only a 100 RPMS off his max. I will probably try that next!

Also, motor height can play a difference in RPMS, hole shot and top end speed. But, if you plan on adjusting motor height read, reread and then reread again what BassCat recommends. There are guys on these forums saying they raised their motor 2 inches when BassCat would only recommend more than 1/2 of an inch on extremely rare scenarios.

Please keep me posted on what you are finding and learning. Its been very difficult to find someone who truly has experience with what elevation does to outboard motor production.

[21XDC]

Ok just a update. Took it out yesterday and ran the 21 laser 2. Jumps up but did have some blowout, Maybe the fact that theres no prop ring and the small barrel? If I start trimming right away I have no issue and shes off and going. Top speed, lol 52mph. But hey at least we got on plane.
21XDC still a 23p tempest plus? Will I need a prop ring? Sorry for all the questions just want to make sure its right before I spend 600.00 lol.

What were your rpms?

[g352nv]

What were your rpms?

I stopped at 5700 I dunno how much more it would go but it had more to go but I didnt want to red line it.

[g352nv]

This is going to be a fun/frustrating thread over the next month or so. Like Mike464 mentioned earlier, I am trying to get my PII set up to fish at Flaming Gorge; ~6500 feet of elevation. When I bought the boat it came with a Fury4 25P. I was turning 5100 RPMS at 4500 feet of elevation. I really dont think that the 23P Fury three blade is going to be the answer. Yes, going from four blades to three will increase rpms and speed. But it will kill hole shot. And going from a 25P Fury to a 23P Fury will only benefit you at most 400 RPMS. After a call with Mercury, researching many threads, and chatting with Mike464 and others I decided to go with a Bravo 1 XS 24P which would act like a Fury 22P (Which obviously doesnt exist). The 24P ran at 5450 RPMS at 4500 feet. I then went with a Bravo 1 XS 22P and ran it this weekend at the elevation of 6500 feet. I maxed out at 5350 RPMS. Which means Im still 400 RPMS short. The hole shot has been incredible, which at high elevations is typically is awful. I have a friend who fishes Flaming Gorge regularly and runs a Sabre with a 150. He is running a Tempest 21P and is only a 100 RPMS off his max. I will probably try that next!

Also, motor height can play a difference in RPMS, hole shot and top end speed. But, if you plan on adjusting motor height read, reread and then reread again what BassCat recommends. There are guys on these forums saying they raised their motor 2 inches when BassCat would only recommend more than 1/2 of an inch on extremely rare scenarios.

Please keep me posted on what you are finding and learning. Its been very difficult to find someone who truly has experience with what elevation does to outboard motor production.

Nice to have someone else to gauge from. But it sux trying to figure this out at 600.00 a prop lol.

[John Jackson]

I didn't see a mention of motor brand. If it's a Mercury DFI, the trophy runs very well on them, and with the exception of some very early ones, they are small tube 4 blade props. They are also faster than most other 4 blade props.

[btribby]

I stopped at 5700 I dunno how much more it would go but it had more to go but I didnt want to red line it.

What are the max rpms of your motor?

[btribby]

@21XDC

Im running a 2010 BassCat PII with a 200 Mercury ProXS. I recently purchased a Bravo 1 XS 22P and thought for sure that would be my answer at 6500 feet of elevation. But, Im still 400 rpms short. Full tank of gas, nothing in the live wells, only me in the boat, regular amount of tackle and supplies. No poles. I wish the Bravo came in a 20P.

I think my best two options right now are:

21P Tempest or a 21P Trophy. I don't mind giving up a couple mph to ensure a good hole shot with a four blade. Do you know how the pitches compare between the Bravo's, Tempest and Trophys? If the pitches perform relatively the same then Im thinking I will need a 19 pitch in either the Tempest or Trophy.

I would really like to hear your opinion. I also plan to chat with Mercury tomorrow to get their opinion. Thank you.

[John Jackson]

A 19 trophy or tempest would be close to a 20 bravo. I would go trophy as holeshot is better. Speed could go either way but usually withing 1 MPH trophy vs tempest.

[21XDC]

@21XDC

I wish the Bravo came in a 20P.

.

But they are offered in a 20P https://www.mertenmarine.com/15.25-x...cury-Propeller