New Boat Prop suggestions

[Sailor61]

Hi guys, new to the forum and have been searching here and elsewhere for the best prop for my new (used) boat. I just bought a 2004 Triton 190 FS with a 2004 Merc 150 XR6. It has a Mercury Tempest 14.625 x 21P on it. I had the engine serviced as part of my pre-buy inspection. I spent 3 days playing with the boat this weekend and got the following results with 500 lbs (me and two teenagers) 1/2 to 3/4 tank of fuel app. 20 gallons, skis, livewell empty.

WOT = 5000 rpm
50mph gps average multiple runs in light chop.

The boat seems to have a lot of bow rise at low rpms but does come out of the hole respectably. It's a little slow out of the hole with a slalom skier.

I use it for fishing and skiing but more watersports in warm weather.

Tight turns the Tempest prop cavitates. I'd like a better holeshot for skiing without giving up to many mph's. Manual says WOT range for this engine is 5000-5600.

I feel like the 21P Tempest is too much prop as I'm at the low end of the WOT RPM range. The Merc prop selector suggests The Highfive 13.25 x 19, Tempest 14.625 x 19 or Vensura 14 x 19

Boats dry weight is 1750 engine is 406 lbs.

I have 3 holes on the transom plate that I could raise the motor.

Also I got a new in box Tempest Plus 14.625 x 21P with hub with the boat that I'm probably going to sell to get a different prop.

Suggestions?

 

[Sailor61]

Re: New Boat Prop suggestions

I didn't get any responses so I continued my internet search and found Dan's discount propellers. I called and had several conversations with Dan he recommended the Stiletto Bay Pro III 14 1/4 x 19P. I ordered it today and it should be here next week. Anyone else running this prop? If yes how do you like it?

 

[Bifflefan]

Re: New Boat Prop suggestions

WOT = 5000 rpm
50mph gps average multiple runs in light chop.

Right at the bottom, but thats fine. Stock props tend to run at the bottom so you dont over rev the engine. Id bet with just you and nothing else you can gain 2 or 3 hundred RPM's.

The boat seems to have a lot of bow rise at low rpms but does come out of the hole respectably. It's a little slow out of the hole with a slalom skier.

Its a fishing boat, not a ski boat. If its to much rise, you may move some weight to the bow or use some make of trim tabs.

I feel like the 21P Tempest is too much prop as I'm at the low end of the WOT RPM range. The Merc prop selector suggests The Highfive 13.25 x 19, Tempest 14.625 x 19 or Vensura 14 x 19

I think the prop is just about right for your boat, but a spare of different pitch can come in handy, use the 19 to ski and the 21 for everything else.

Tight turns the Tempest prop cavitates. I'd like a better holeshot for skiing without giving up to many mph's.

Mine does that also. Less prop "p" wont help.
Go with the 19 for a better hole shot or less some weight.

I have 3 holes on the transom plate that I could raise the motor.

That will make it blow out faster and more often.

All in all, id say your prop is just about perfect.
You can try a 19, but they all are different.
You may drop to a 19 and not change what your looking to change, or more or less than you think.

 

[Sailor61]

Re: New Boat Prop suggestions

New prop arrived yesterday, installed it this morning. Looks great, it seems like the Bay Pro III 14 1/4 x 19 is lighter than the Mercury Tempest Plus 14 5/8 x 21. The center hub is 3/4" shorter than the Mercury prop. Can't wait to test it. I also found my service shop (checked plugs everything's fine, wrong) had Champion plugs gaps .015 - .02 installed. Changed them for NGK, per shop manual, gap @ .040. Engine started 2cnd bump and I picked up 200 rpm, now WOT @ normal load is 5200 with the Tempest. Will run the Bay Pro III this weekend!

 

[sethjon]

Re: New Boat Prop suggestions

Hi guys, new to the forum and have been searching here and elsewhere for the best prop for my new (used) boat. I just bought a 2004 Triton 190 FS with a 2004 Merc 150 XR6. It has a Mercury Tempest 14.625 x 21P on it. I had the engine serviced as part of my pre-buy inspection. I spent 3 days playing with the boat this weekend and got the following results with 500 lbs (me and two teenagers) 1/2 to 3/4 tank of fuel app. 20 gallons, skis, livewell empty.

WOT = 5000 rpm
50mph gps average multiple runs in light chop.

The boat seems to have a lot of bow rise at low rpms but does come out of the hole respectably. It's a little slow out of the hole with a slalom skier.

I use it for fishing and skiing but more watersports in warm weather.

Tight turns the Tempest prop cavitates. I'd like a better holeshot for skiing without giving up to many mph's. Manual says WOT range for this engine is 5000-5600.

I feel like the 21P Tempest is too much prop as I'm at the low end of the WOT RPM range. The Merc prop selector suggests The Highfive 13.25 x 19, Tempest 14.625 x 19 or Vensura 14 x 19

Boats dry weight is 1750 engine is 406 lbs.

I have 3 holes on the transom plate that I could raise the motor.

Also I got a new in box Tempest Plus 14.625 x 21P with hub with the boat that I'm probably going to sell to get a different prop.

Suggestions?

The 14X19 will do the trick.

 

[Sailor61]

Re: New Boat Prop suggestions

Couldn't wait for the weekend, I had to sneak it out today. First impressions WOW! Conditions: Temp 75*F, water calm, wind 3-5, 450 lbs (2 men) 1/2 tank of fuel 10-15 gallons, livewells empty..
Idle speed in no wake zone increased 6.5 - 7 mph gps. Ran it easy for 10 minutes at varying rpms and trim then it was time for a hole shot and top speed. Hole shot was incredible the entire boat lifted with a slight bow rise and was on plane before I could count two Mississippi! As fast as you're out of the hole I had to be quick on trim all the way to max. Acceleration was much better and she topped out @ 5150 rpm and 50 mph gps. The acceleration is much improved as is cruising @ 22 mph holding speed and plane(wakeboarding).
So it looks like I gave up 3-4 mph but the acceleration and hole shot are much improved. Being picky I would have loved to have the rpm's around 5400 under these conditions but for all I know the tach could be off a couple hundred, the speedo is off 4 mph mid to high end vs gps.
Got it home pulled the prop everything looks beautiful, new coat off grease and 55# of torque and we'll test it thoroughly towing etc. this weekend. So far I love it!

 

[sethjon]

Re: New Boat Prop suggestions

New prop arrived yesterday, installed it this morning. Looks great, it seems like the Bay Pro III 14 1/4 x 19 is lighter than the Mercury Tempest Plus 14 5/8 x 21. The center hub is 3/4" shorter than the Mercury prop. Can't wait to test it. I also found my service shop (checked plugs everything's fine, wrong) had Champion plugs gaps .015 - .02 installed. Changed them for NGK, per shop manual, gap @ .040. Engine started 2cnd bump and I picked up 200 rpm, now WOT @ normal load is 5200 with the Tempest. Will run the Bay Pro III this weekend!

If the center hub is shorter you need a washer that goes on just before the nut or you will have play in the prop.

 

[Robbabob]

Re: New Boat Prop suggestions

You probably realize you could go with an even smaller pitch. You'll get the rpm where you want at WOT and improve hole-shot a little more. Not that you needed it today, but you may when filling the tank full and having a few more on board for the skiing, etc. Just sayin'

Either case, you're happy as Punch nothing better than a plan coming together! ^5

 

[Sailor61]

Re: New Boat Prop suggestions

Yeah there is a Bay Pro III in 17, I can swap for but couple of hold backs in pushing the rpm's right now. I've had it two weeks and it's run more with me than in the previous 3 yrs, had about 65 hrs. per original owner. Everything seems real tight, it had the wrong plugs and gap and it has a new prop.. I'm in the rpm range, assuming tach is accurate, and it may loosen up a little with regular use. I may sell the Tempest 21P and get a BPIII 17 for my backup

 

[Sailor61]

Re: New Boat Prop suggestions

Theoretical question. Assume no slip or same slip. Which would actually perform better a:
19" prop spinning @ 5200 rpm = 98,800"
or a
17" prop spinning @ 5600 rpm = 95,200"

Both are in my rpm range. I'm happy with my BPIII just trying to understand how the 17" would perform better...?