# Anyone with a 18-19' bass boat (Triton or other brand) - need prop advice!



## bman

This spring I bought a new 2008 Triton 18x2 with a 150 Mercury Optimax. It came with an aluminum quicksilver prop - have no idea on the specs.

I am STILL in the break-in period but have noticed that it does ventilate/cavitate quite a bit. I can get it down to a manageble amount by properly using my trim, but it still seems a bit sensitive and excessive for my tastes.

My father (Ranger bass boat owner for almost 30 years) tells me that the right stainless steel prop will dramatically improve my boat's ability to get on plane and even accelerate and handle better not to mention reduce ventilation/cavitation.

I went to mercury's online "prop selector" tool and it recommended the following Mercury SS props:

1.) High Five (5-blade)
2.) Laser II (3 blade)
3.) Tempest Plus (3 blade)
4.) Trophy Plus (4-blade)

Anyone running an 18-19' bass boat with a 150 have any prop recommendations for me? Better yet, how about anyone with either a Triton 18 Explorer, 18x2 or 18x3 running a Mercury Opti 150?

These ss props are expensive, so I'd hate to buy one only to end up dissatisfied with my new prop! Any Mercury dealers do prop demos?

thanks!


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## UFM82

Stick with the Tempest or the Trophy. Hi5's IMHO are ski props although some guys like them for bass boats. Lasers are great for ski boats or runabouts but the small diameter doesn't give the bow lift the Tempest or even the Trophy provides. 
The Tempest is my pick of the bunch for boats that run hi-horsepower and run shallow. A Tempest will run great when trimmed and throwing a moderate tail, about cowling high. Trophy props are also a popular pick if holeshot and vibration are important. I would think a 23 Tempest should work well on that boat, maybe even a 25. What are your WOT RPM's? I know you are in break-in still so run the aluminum until you are done with that and then start playing. If your range is 5500-5800 then try to hit the upper end of that range when running full tilt and trimmed. 
Are you trimming fully down when starting? Do you have to feather the throttle to keep from cavitating? Where is the propshaft in relation to to keel? What pitch is the aluminum prop? 3 blade? 
Your father is correct- an SS prop will greatly improve your boat's performance. You can change holeshot characteristics by changing the PVS plugs and that's easy. You can experiment for the best all around performance by changing them. 
If you don't have a dealer that will let you play, eBay is a great place to find a used prop. I've bought several there and pay 1/2 of what new costs and the last Tempest I bought WAS new and only cost me $225. 
Good luck- you've got the boat and the engine, now it's time to dial her in. 
UFM82


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## bman

> I would think a 23 Tempest should work well on that boat, maybe even a 25.


First off, thanks for your detailed response and ideas! I called a local Triton dealer today and he immediately recommended a 23P Tempest!



> What are your WOT RPM's?


Not sure - I get the more serious smartcraft audio alarm bell when I run at WOT for more than 3-4 minutes straight. Pretty sure it's because I'm still in the break-in period . . .I probably only have about 4-5 hours of run time on the engine so far (bought it in April and have had it on the water 4 times so far. 3 very short trips and one all-day trip.)



> I know you are in break-in still so run the aluminum until you are done with that and then start playing. If your range is 5500-5800 then try to hit the upper end of that range when running full tilt and trimmed.


I did learn that the prop should have the pitch specs stamped into it, so when I get home from work today I'm going to see what the dealer put on there. Based on what I'm experiencing with cavitation, I wouldn't be surprised to see a more aggresive pitch (say, less than 23) but we'll see.



> Are you trimming fully down when starting?


Yes




> Do you have to feather the throttle to keep from cavitating?


Yes, especially when the boat just hits "on-plane".



> Where is the propshaft in relation to to keel?


Another thing I'll measure tonight.



> What pitch is the aluminum prop? 3 blade?


It's a Mercury quicksilver 3-blade aluminum prop. Will check to see what the pitch is tonight and report back.

Your father is correct- an SS prop will greatly improve your boat's performance. 



> You can change holeshot characteristics by changing the PVS plugs and that's easy. You can experiment for the best all around performance by changing them.
> If you don't have a dealer that will let you play, eBay is a great place to find a used prop. I've bought several there and pay 1/2 of what new costs and the last Tempest I bought WAS new and only cost me $225.
> Good luck- you've got the boat and the engine, now it's time to dial her in.


I am just learning abour the PVS plugs but honestly don't know what they do, where they are located or how easy it is to swap them in and out.

Many, many thanks again. I will do some additional investigating and report back!


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## Champion188 Elite

A 23 or 24 Tempest Plus is what you want.A Trophy Plus is also a good choice especially on the Tritons' .A 25 pitch IMHO is too much for a 150HP,it may run well on top end but will probably be a dog on the holeshot even lightly loaded.

The PVS holes help you tune the Tempest/Trophy Plus to your boat,you can mix holesizes or remove the plugs to get the prop to vent properly on holeshot.If it vents to much the prop will blow out(meaning it will just spin up real fast you will over rev and the boat will fall on its face never coming out of the hole) Thus the need to try different size plugs to see which combination of plugs works the best.
You can install or remove the plugs very easily,they just pop in and out.
The PVS plugs are for adjusting holeshot only,they have no effect on speed or handleing.


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## bman

Champion188 Elite said:


> A 23 or 24 Tempest Plus is what you want.A Trophy Plus is also a good choice especially on the Tritons' .A 25 pitch IMHO is too much for a 150HP,it may run well on top end but will probably be a dog on the holeshot even lightly loaded.
> 
> The PVS holes help you tune the Tempest/Trophy Plus to your boat,you can mix holesizes or remove the plugs to get the prop to vent properly on holeshot.If it vents to much the prop will blow out(meaning it will just spin up real fast you will over rev and the boat will fall on its face never coming out of the hole) Thus the need to try different size plugs to see which combination of plugs works the best.
> You can install or remove the plugs very easily,they just pop in and out.
> The PVS plugs are for adjusting holeshot only,they have no effect on speed or handleing.


Thanks for your help too. What you are describing is what I am experiencing . . .ventilation especially in the holeshot.

I just checked my "stock" prop . . .it's a Quicksilver 1918 21P. I believe this is what Mercury brands as a "Black Diamond" or "Black Max." 

I will just hang on to this prop and keep onboard as a backup.


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## EDD

something wrong if an alarm is going off even in brake-in , alarms go off for a reason


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## seapro

Get ahold of Greg at http://propmyboat.googlepages.com/ he'll get you set up right!! !%


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## bman

EDD said:


> something wrong if an alarm is going off even in brake-in , alarms go off for a reason



You could be right, but your note made me double-check the manual. Turns out I effectively "reset" the 120 minute break-in period when I had to purge the on-engine oil injection reservoir (dealer didn't do it properly.) So, I'm actually probably still in the first 120 minutes of the break-in due to my reset (something the ECU does automatically when you follow the oil system air purge procedures.)

The manual doesn't state that I will get a warning and trigger guardian safe mode if I run at WOT during the first 120 minutes of break-in, but it does recommend not running at WOT or idling for more than a few minutes during this break-in period. I'm hoping that's why I'm getting the more serious horn warning and triggering the guardian safe mode when I've tried to run all-out! We'll see . . .

Still working on prop selection . . .might just wait until I'm fully broken in so I can learn more about what my boat can do on the top end (rpms, top speed) before selecting a new prop.

Sea-pro - thanks for your advice!


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## UFM82

They allow exhaust gas to flow out over the prop blades at start-up, actually causing some cavitation and that allows the prop to spin up faster. It's not rocket science but even 1/4" changes in the hole size can effect the holeshot. 2 strokes don't have a lot of torque and by aerating the water over the blades, it helps the prop break free a bit. When the boat is sitting still, the exhaust will exit the hub at the first opportunity which is the vent holes. Water pressure keeps it from going out the hub. Once the water is flowing though the pressure in the hub goes away and the exhaust exits through the prop like normal. The vents don't do anything anymore.

Have fun with it and play if you can. It's very interesting to see what effect changes have on a boat. I have a 13 pitch Mirage that I pull tubes with on my boat. Holeshot will rip your head off but top speed is about 34 mph at 6,000 rpm. My 19 Tempest will still pull pretty good at slow speeds but top end is over 50 at 5500 RPM. I have a 19 Offshore 4 blade that is smooth as butter but only runs 48 at 5800 rpm. It's fun to switch around and see what happens.


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## big_b16

I'd ask this question at bassboatcentral.com on the Triton page. There is surely someone there who has asked that question for your setup. You can also post a question after a search on the "props" page.


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## bman

big_b16 said:


> I'd ask this question at bassboatcentral.com on the Triton page. There is surely someone there who has asked that question for your setup. You can also post a question after a search on the "props" page.


Someone pm'd me and mentioned this - great advice! I did do that and everyone's advice has helped me narrow my prop selections down. Here's an update to my boat setup issues:

Went out since my original post. My motor has a quicksilver aluminum 21P prop. With two guys, 3/4 fuel, full gear, empty livewell, the holeshot was perfectly fine. Top speed was only around 50mph at redline of 5750 (analog tach) - I have alot of throttle left, which tells me I could probably go with a 23 pitch prop.

When I was running at 45-50mph (GPS) with lots of trim, my water pressure dipped quite a bit (<10 psi) but I quickly trimmed down a little to get it back to 10-20 psi depending on trim level. I'm still trying to determine what's an appropriate water pressure when running full bore but it sounds like these Optis don't make alot of psi due to their cooling system design.

My alarm went on the previous time I was out as well as this time for a few seconds due to over-revving the engine a little. As soon as I backed it down and watched the tack more carefully, it was fine.

I'm guessing that aluminum prop just isn't meant for bass boats - especially when you start pushing 50 mph.

I am headed to Alum Creek on Friday and hope to demo a 23P SS Tempest Plus prop. I'll report back whatever I end up doing.


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## big_b16

I wouldn't run an aluminum prop on a higher horsepower motor. There's a reason most of the 150 and up motors come with the stainless props. Be careful overrevving your engine...many will put it in a safe mode that has to be reset by a mech (of course I'm sure there is a way around this). Regardless, there's a reason it's called red-line...red=bad. Sounds like you're getting it dialed in. If your RPMs are too high at WOT, then increase your pitch. I can't remember, but I think it's like 300 RPMs per inch of pitch or something like that. With the smaller pitches, you'll get better holeshot because your prop will be able to turn the water quicker, but will over-rev at WOT. Good luck...don't bang up those stainless props, it can be a wallet emptying endeavor.


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## bman

UPDATE:

I demo'd a Tempest + 23P. Definitely saw an improvement. The prop has the fairly large holed plugs already in place. I hit 55-57 at 5100-5400 rpm using this prop. My analog water pressure gauge is still showing pretty low psi if I trim up enough to hit 57 mph. Holeshot was acceptable but not lights-out great. I had 2 adults (each 200+ lbs) + full tank of gass + full gear but empty livewell. Other than the rpms, I was fairly satisfied.

My rpms tells me I might be better off with a slightly lower pitch . .. my plan is to purchase the 23P tempest and have it re-worked to a 22P. That should put me exactly where I need to be at WOT rpms (Merc specs indicate a range of 5250-5750 for my 150 Opti.)

BBC has been very helpful . .. have an active thread going with 3 other Triton 18x2 owners all in a quest to improve the boat's performance!

I'm going out again this Sunday and will run the same prop again to see if it's any different or if maybe my motor just continues to open up a little more. No alarms or any issues despite the low psi reading at WOT for 5-10 minutes at a time. Maybe the gauge is off or the gauge water pickup is clogged.


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## Champion188 Elite

What kind of water pressure are you getting when trimmed out? You really should go no lower than [email protected] open! If you are not reaching wide open throttle(5600-5750) you will not get great water pressure. Does your boat have a jackplate? Something doesn't sound right here,your rig should run much faster than it is.Have guys on the BBC board asked about your prop to pad measurement? Are you throwing a rooster tail when trimmed out?How high or low is it? Sounds like your engine may be mounted to high or low.


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## UFM82

Sit the boat in the driveway and level the hull. Measure from the ground to the botton of the keel and then measure from the ground to the propshaft. The difference will tell you where the propshaft is in relation to the keel. I think you want about 2". That is, the shaft should be about 2" below the keel. If not, you'll want to raise or lower the engine on the transom. This isn't hard to do but you need to be careful. When you trim up and lose water pressure, the intake ports are getting too high in the water and you lose the pressure. Dropping the engine down even 1/2" can make all the difference sometimes. Don't let an Opti overheat- they really don't like that. :-(

Your speed sounds about right but with some tweaking you should be able to beat 60 IMHO. My center console will hit just over 50 with my 150 and it probably weighs 1,000 lbs more than your boat. AND I run a 19 Tempest. You should break the 60 mark easily once everything is dialed in. 

UFM82


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## bman

Champion188 Elite said:


> What kind of water pressure are you getting when trimmed out? You really should go no lower than [email protected] open! If you are not reaching wide open throttle(5600-5750) you will not get great water pressure. Does your boat have a jackplate? Something doesn't sound right here,your rig should run much faster than it is.Have guys on the BBC board asked about your prop to pad measurement? Are you throwing a rooster tail when trimmed out?How high or low is it? Sounds like your engine may be mounted to high or low.


My water pressure is around 10 psi fully trimmed out when hitting 57 mph. If that measurement is accurate from my analog psi gauge, that's too low. I've learned that the opti's need at least 12 psi at wot. Like you said though, I'm only turning around 5100-5400 rpms with the 23 tempest so that's probably part of the reason for my slightly low psi.

Yes; I get a good roostertail trimming up to optimize top end speed. No, I do not have a jp and never will since I don't have an inch to spare in my garage! Regarding my top speed....based on my discussions with other 18x2 and x3 owners without a jp, my performance is about right. Seems max speed is about 57-59 with the 18x boats depending on conditions. 

My guess is if i go with the 22 pitch tempest, my rpms will go up enough to net me around 59 mph.


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