Prop advice...

[Full Force]

I need to talk to someone who knows props good, my limited now runs 52MPH ( I know its slow!) it is at 4800 rpm, it has no more in the engine, it is tuned as good as it gets, right now I have a 3 blade 19P SS Rapture, I bring the drive out as far as I can until it hits the trailer limit switch and runs 47-48 MPH, if I bring it up a tad more using the trailer switch it will go 52 almost 53, do I need a bow lifting prop? If so what is a good bow lifting prop? Now that the engine is right I want to play with props. Any advice would be great.
Thanks, Tim

[ROGUE]

3 blade, big ears, forward rake, is the best bow lift you can get. Original Mirage. There are some real old michigan ss props built for the scarab 3 that are real good too. You might need some more rpm's so try dropping pitch or diameter.

[Bomar76]

if I bring it up a tad more using the trailer switch it will go 52 almost 53,

If you keep doing that, what you are REALLY gonna need are u joints.

Try to envision the loading put on them at those angles....

[THRILLSEEKER]

Call Julie.;)

[Full Force]

3 blade, big ears, forward rake, is the best bow lift you can get. Original Mirage. There are some real old michigan ss props built for the scarab 3 that are real good too. You might need some more rpm's so try dropping pitch or diameter.

I don't really want to drop pitch, my cruise speeds suck now, 35 at 3500, I liked my cruise with a 21P 40@3600 but it does not spin past 4400 and planes for crap, what is the smallest diameter 19P?

[frank the tank]

high 5 19 x 13 3/4 good for your boat

[Bomar76]

[QUOTE=245 limited;12719]I don't really want to drop pitch, my cruise speeds suck now, 35 at 3500, I liked my cruise with a 21P 40@3600 but it does not spin past 4400 and planes for crapQUOTE]


With that prop you are lugging the hell out of the engine.....not a good thing at all.

[Full Force]

If you keep doing that, what you are REALLY gonna need are u joints.

Try to envision the loading put on them at those angles....

It is just a few taps and it has been fine doing it for 3 seasons now, i pull the drive and check/grease every season, that is alot of MPH I am losing without doing that, I need to figure out why I need to do that to get top speed. Nobody has been able to help me with this yet...

I have no vibration at all either, if I was at a dangerous angle wouldn't I have a vibration?

[Full Force]

[QUOTE=245 limited;12719]I don't really want to drop pitch, my cruise speeds suck now, 35 at 3500, I liked my cruise with a 21P 40@3600 but it does not spin past 4400 and planes for crapQUOTE]


With that prop you are lugging the hell out of the engine.....not a good thing at all.

I am not running the 21 for that reason, I have a 19 now, it planes great with the 19P I had the 21 so I thought I would see what it did, obviously it does not do well.

[THRILLSEEKER]

QUIT FUKING AROUND AND BUY THE 311!

[Full Force]

high 5 19 x 13 3/4 good for your boat
where do I find the info?

[ROGUE]

high 5 19 x 13 3/4 good for your boat


granted our boats are quite dissimilar but everytime I added blades, i lost rpm, top end and hole shot. I think more blades are better if you are surfacing the prop.

Frank, You out this weekend?

[Full Force]

QUIT FUKING AROUND AND BUY THE 311!

I know, I am not going to know until September, we are goiung into our second attempt for IVF to have a kid, if that goes well I will have the money, otherwise I go broke again.

[Bomar76]

It is just a few taps and it has been fine doing it for 3 seasons now, i pull the drive and check/grease every season, that is alot of MPH I am losing without doing that, I need to figure out why I need to do that to get top speed. Nobody has been able to help me with this yet...

I have no vibration at all either, if I was at a dangerous angle wouldn't I have a vibration?

There is a reason the drive has a limit on trim up and a seperate trailer up function for when the engine is off.
The torsional loading on the joints is tremendous at high angles.
You ARE doing damage running the engine any time the drive overtrimmed.....just because it held together for a couple years doesn't mean otherwise.
Have you ever checked the trim limits to see if they are set properly?
THAT might be your problem is the limit switch is set too low....

[Full Force]

granted our boats are quite dissimilar but everytime I added blades, i lost rpm, top end and hole shot. I think more blades are better if you are surfacing the prop.

Frank, You out this weekend?

I cannot remember what it was last year but I tried a 4 blade and it did not do well either, lost in all areas, I cannot remember what the pitch and diameter was now.

[THRILLSEEKER]

I will give you Gilligan for a week, yall will forget about ever wanting a kid again after having that little chithead for a few days.

[ROGUE]

There is a reason the drive has a limit on trim up and a seperate trailer up function for when the engine is off.
The torsional loading on the joints is tremendous at high angles.
You ARE doing damage running the engine any time the drive overtrimmed.....just because it held together for a couple years doesn't mean otherwise.
Have you ever checked the trim limits to see if they are set properly?
THAT might be your problem is the limit switch is set too low....

all true, but under the right conditions, I can bring mine up a little, get them to draw some air, up the engine rpms and actually get more speed since i am getting into better hp range. but I like the bigger props for cruise range. its a dance.

[Full Force]

There is a reason the drive has a limit on trim up and a seperate trailer up function for when the engine is off.
The torsional loading on the joints is tremendous at high angles.
You ARE doing damage running the engine any time the drive overtrimmed.....just because it held together for a couple years doesn't mean otherwise.
Have you ever checked the trim limits to see if they are set properly?
THAT might be your problem is the limit switch is set too low....

Maybe the limit settings are bad, I do not know how to do it, I would think that could be the problem, like I said, it does not vibrate and on any other boat with overtrim it did vibrate,the gauge goes from down to up with no inbetween, I am not sure how to mess with the sensors.

I realize damage can occur from it, I really think that I am not running in a dangerous setting, i looked once when I shut off the boat and the drive did not look like it was at a danderous angle, the angle was less all the way up then it was all the way down.

[Full Force]

I will give you Gilligan for a week, yall will forget about ever wanting a kid again after having that little chithead for a few days.

I have 2 of my own 4 leggers to deal with!

[Bomar76]

21-3/4" Center of pin to center of pin, for max trim up.

[Full Force]

21-3/4" Center of pin to center of pin, for max trim up.

I will try to check that, boat is in the water!

[ROGUE]

I cant wait for you all to meet POGO. Hollies insane australian cattle/ jack russel dog.

[Bomar76]

Port side is the limit switch

[Bomar76]

Go here:
http://www.boatfix.com/merc/Servmanl/6/6covr3.pdf
click on section 1C
you will find instructions on setting trim
May not be your drive, but it will work on all Alphas and MR's

[Full Force]

Port side is the limit switch

OK, I will try check that measurement, that will tell me alot right there, I haver to pull the boat to mess with the switch so I may need to wait on that.

[ROGUE]

OK, I will try check that measurement, that will tell me alot right there, I haver to pull the boat to mess with the switch so I may need to wait on that.

Ive done it in the water, just needs to be clear and calm and put some bigguns on the bow.

[Full Force]

Ive done it in the water, just needs to be clear and calm and put some bigguns on the bow.

I can probably do it at the Casino this weekend!

[ROGUE]

hehe,