Prop identification selection and preformance

[Big Cliff]

OK, I have a 60 hp Mercury

 

The numbers on the prop are 73136A40?13 the ? could be a B or a P (or something else but it is painted in)

 

The boat doesn't seem to get up on plane as fast as I think it should and at WOT my RPMs are really pushing the limit. Top end speed isn't as much of a concern to me as lower end. I would like to acheive less speed for trolling (currently about 2.3 mph) and quicker jump up on plane. Is this the right prop for what I want to do?

 

The boat is rated for a 75 but the dealer "ASSURED ME" that the 60 was plenty of power for this package!

[Roy]

This might help you Cliff.

 

http://www.propmd.com/t-PropellerBasics.aspx

[Fish Farmer]

Cliff

If your 60 is a 4 stroke, you'll find it won't have the bottom end as a 2 stroke 60hp. I have a 50 4 stroke on my small boat, each extra person I have in the boat, I have a problem getting up on plain. The 4 stroke doesn't have the RPM at bottom end as a 2. Dropping the pitch on your prop can cause you to over rev and blow your motor at top end. Be careful Cliff. I know it's to late now but you should have maxed out with the 75hp.

I find the 4 strokes are gut-less coming out of the hole.

Edited July 29, 2009 by Fish Farmer

[Greencoachdog]

I wouldn't mess with the prop, throw out a drift sock or use your bowmount trolling motor for low speed trolling.

 

I have a 50 hp 4 stoke on my 17' deep vee that is rated for a 90 hp max. I'm not a speed demon on the water and it does just fine for me!

 

One thing you may want to consider on getting up on plane faster is your motor tilt, tilted all the way down for getting up on plane... then tilt it up after it gets up on plane for more speed.

[aniceguy]

cliff find a 4 blade stainless prop should help with the low end out of the hole

[Greencoachdog]

Before you buy a stainless prop, you may want to read this if you haven't already.

 

http://www.ofncommunity.com/forums/index.php?showtopic=34546

[aniceguy]

An aluminum prop will work on the hp engine but hole shot will vastly improve with ss....Hitting a rock at 4mph can ddo damage regardless of the prop , an aluminum will flex and break easier then ss. IMO any boat above 115 is better suited for ss or a painted steel prop

[Dutch]

A bent prop shaft is a symptom of a larger problem.

 

Thing is, Cliff is asking for advice, looking for the best tool to overcome a problem. A stainless prop IS the best single piece of equipment to overcome a poor holeshot.

 

Cliff - what RPM's are you turning with your current prop at WOT? What is the engine rated for - it may be on the same sticker as your serial number. If you are hitting your max RPM's with your current prop, you are in the right range as far as pitch goes, if you aren't and are below your max. RPM's, you may need to turn a lower pitch prop, which will give you better hole shot.

 

If there are vent plugs on your prop, they usually have rubber plugs in them, you can take one or more of those out to get better venting and that may improve your hole shot.

 

This is almost a given, but make sure you are trimmed all the way down when you take off. I have an acquaintance that always tries to take off trimed up to the tilt piston of his motor, drives me nuts. Someone has to go up to the bow to get it to plane faster.

 

I have learned a lot about this stuff just reading on the web, best thing you can do is to read and ask questions.

[LeXXington]

I think I was the king of not getting on a plane when loaded down.

 

Some of the thing like others have noted.

 

Propsize. can make a differene but watch the RPM's.

trim is everything,. trim all the way down and bring her up as you push power.

I found a back fin helped me

 

and the worst part I have to get people to move more too the centre of the boat even with the new 40 hp to get on a plane faster

 

Good luck

[DRIFTER_016]

OK, I have a 60 hp Mercury

 

The numbers on the prop are 73136A40?13 the ? could be a B or a P (or something else but it is painted in)

 

The boat doesn't seem to get up on plane as fast as I think it should and at WOT my RPMs are really pushing the limit. Top end speed isn't as much of a concern to me as lower end. I would like to acheive less speed for trolling (currently about 2.3 mph) and quicker jump up on plane. Is this the right prop for what I want to do?

 

The boat is rated for a 75 but the dealer "ASSURED ME" that the 60 was plenty of power for this package!

 

 

Changing the prop won't help your trolling speed unless you really change the pitch a ton. Which will trash your holeshot and top end speed.

What are your current WOT RPM's at? Your WOT rpm should be between 5500 and 6000 rpm. If you are at or above 6000 rpm you can go up on your pitch. Your prop is a 10 3/8" diameter 13" pitch. For every 1" of pitch you go up you will lose about 200 rpm off your top end.

Lets say you are at 6200 WOT rpm, if you go to a 15" pitch prop you should be at 5800 WOT. As this prop will grab more water your holeshot should improve, but you will lose about 1-2 mph on the top end. If you go down on pitch the opposite is true. More top end rpm and weaker holeshot.

If you are in that 5500-6000 rpm range think about putting a set of Nauticus smart tabs or pro-trollers on your boat.

 

Nauticus Smart Tabs

[Fish Farmer]

1 more tip Cliff, as Lex mentioned the Shark Fin or a buddy of mine installed spring loaded trim tabs on his 14'. He told me that helped. I was shocked when I seen them. I didn't know they made them that small. Don't know were he bought them. I've heard him mention Hully Gully because he lives that way near London.

 

Drifter beat me by a click. Thanks drifter, thats what I was talking about. I checked, Bridge Marine in Dover sells them.

Edited July 29, 2009 by Fish Farmer

[aniceguy]

hey Dutch isnt it time to change the musky to a bass in the avatar lol

[ecmilley]

Cliff it may be in the set-up, sounds like you have the right prop if your wot rpms are correct.

Have a 40 hp merc on shawns 16ft lund it gets up and planes perfect, Read this it may be a pad adjustment needed.

http://www.bassboatcentral.com/basicsetup.htm

also may have to wait out the break in period most 4 strokes really start working good once they get a few hours on them

Edited July 29, 2009 by ecmilley

[hirk]

Cliff a prop change in keeping with the rpm range you should be running at WOT will do nothing for slowing you down trolling.What you can do is keep your WOT rpm's where they should be via keeping the prop you have and installing a cav. plate fin to improve your hole shot,problem solved.

[Big Cliff]

Wow, thank you for all the replies and information, I think I am going to look into a set of the tabs. I also had a talk with the marina today and they checked and apparently that isn't the best prop for my package, they are sending me one (free) with an apology, that they say should solve most of my issues other than the trolling speed. With the current prop I am pushing the RPM limit for my package and would actually exceed the max rated RPMs if I were to hold the throttle wide open. I should have the new prop here for the weekend, I'll let you know how that works. In the mean time it looks like I have pleanty of reading to do!

[Guest skeeter99]

OK, I have a 60 hp Mercury

 

The numbers on the prop are 73136A40?13 the ? could be a B or a P (or something else but it is painted in)

 

The boat doesn't seem to get up on plane as fast as I think it should and at WOT my RPMs are really pushing the limit. Top end speed isn't as much of a concern to me as lower end. I would like to acheive less speed for trolling (currently about 2.3 mph) and quicker jump up on plane. Is this the right prop for what I want to do?

 

The boat is rated for a 75 but the dealer "ASSURED ME" that the 60 was plenty of power for this package!

 

here go to the mercury marine prop selector site

 

 

http://appcenter.mercurymarine.com/propSelector/home.do

[Big Cliff]

Boy, that is a good site, according to it, I should be using a 14 pitch prop. I'll see what the dealer sends me!

[JPD]

double post! sorry!

Edited July 30, 2009 by JPD

[JPD]

Cliff, Drifter hit the nail on the head. Great product and they did wonders for my 17 footer a few years back. Really helped with hole shot and eliminated all back wash when coming down off plane even suddenly. May even slow down your trolling a bit.

 

JP

[danbouck]

I don't want to hijack the thread at all but is the stainless steel worth the money?

[POLLIWOGG]

Can you drop some speed by trimming the motor way up?

[Dara]

If I trim mine way up it starts to porpoise really bad.

 

I just put on the rpm controller for trolling. Sure hope that does what they say it will.

[hawg_hauler]

If your having a hard time getting good holeshot with a 13, a 14 (unless it is a four blade) won't help and a 15 would make matters even worse! There seems to be a lot of bad information in this thread, confusing at the least.

[DRIFTER_016]

Cliff, Drifter hit the nail on the head. Great product and they did wonders for my 17 footer a few years back. Really helped with hole shot and eliminated all back wash when coming down off plane even suddenly. May even slow down your trolling a bit.

 

JP

 

JP

The Pro Trollers are Smart Tabs but they also have the ability to flip down and act as a brake to slow trolling speed. The tabs will get you on plane faster and keep you there at a slower speed.

When you are running the boat and don't need to go super slow they are no different than the smart tabs, but when you want to slow down your trolling speed just flip a lever on the top mount of each tab and they flip down an act as a trolling brake. Nauticus guarantees a 30% decrease in speed.

[POLLIWOGG]

I was referring to your trolling speed, if you trim way up the prop gets less bite and the prop wash meets less resistance = less thrust , hopefully = less speed.