Need replacement prop for Mercury 150 XR6

Ragin Cajun

Recruit
Joined
May 29, 2010
Messages
1
Hey fellas....I've got a '93 19-foot Cajun bass boat with a '93 Mercury 150 hp XR6....My question is what make/model/diameter and pitch of the prop do I need to get the maximum speed out of this engine without harming it. I just bought this boat last week from the original owner and love it. The problem with the prop on it, (3-blade) is that it doesn't get the boat fully up and out of the water. I have no idea what diameter or pitch is on the engine now. I do not tournament fish and don't care about hole-shots...

Can anyone tell me what I need?

Thanks,
Matt
 

hwsiii

Commander
Joined
Jan 25, 2009
Messages
2,639
Re: Need replacement prop for Mercury 150 XR6

Matt, welcome to Iboats prop forum and I will try to help you as much as I can but without more information no one can help you, and I will tell you I need more information than anyone else. But if you would like my help fill this form out and I will help you as much as I can.

You might try reading this for a better understanding of motor height, changing props for better performance, and for the major differences between aluminum props and stainless steel.

http://forums.iboats.com/showthread.php?t=369057


If you would prefer to not go to this much trouble there are many other people who will come along and gladly help you.

1. Year, make and model of boat
2. Length, width and base weight of boat, look for boat decal on back of boat
2a.What is the maximum recommended HP for your boat
3. Number of people and gallons of gas normally on boat and what do you use the boat for
4. Year, make. manufacturer and model of motor and recommended Wide Open Throttle (WOT) range
5. HP and gear ratio of motor IMPORTANT
If you don?t know the ratio, you need to pull the plugs out and put a piece of tape across the prop and the lower unit and then cut it between the prop and the housing then do the same thing on the flywheel and turn the motor until the tape lines up with each other on the prop, it is easier if two people do this, so one can watch the prop while the other counts the revolutions of the motor
6. Anti-ventilation Plate height above keel of boat if it is an outboard in inches, use a straight edge under the keel and sticking out to the anti ventilation plate for a reference
Motor Transom Height
AntiventilationPlateStraightEdge-2.jpg


When the boat is running in the top 20% of your speed you should be able to see the anti ventilation plate very clearly at the top of the water and have water just splashing over the top of it.

Correct Anti Ventilation Height

correctheight.jpg

7. WOT RPM and speed from your current prop and how much gas and how many people were in the boat for the test data and is the speed by GPS. Make sure you trim the prop up until it starts ventilating and then just trim in until it quits ventilating.
RPM _________ Speed ______ GPS ______ No. of people ______ Gal. Gas ________
8. Make, model, diameter, pitch, number of blades and whether SS or aluminum prop and does it have a hydrafoil, dolefin or trim tabs
9. Has your motor been tuned up lately and have you checked that the carburetor butterfly is opening all the way by just pushing the throttle at the helm and not at the carburetor, checked compression, and looked at the plugs and checked spark as well as timing and advance, all of the foregoing could be the reason your prop is not attaining full RPM
10. What problems are you trying to cure or what are you looking for the boat to do that it is not doing the way you think it should or to your expectations and does the prop show any damage that you can see

REMEMBER, The numbers I give you will be NO better than the information you give me. I use a computer program I designed to find the correct pitch and then knowledge to pick a Better prop design for your boat.

The only thing I ask of you is to come back and give me a report of WOT RPM and speed for my database.



H
 

walleyehed

Admiral
Joined
Jun 29, 2003
Messages
6,767
Re: Need replacement prop for Mercury 150 XR6

Ragin, a 150 on that 19ft'r isn't going to set any performance records in the near future-not to be rude.
Does this app have a jackplate? I'm sure it has a stepped hull so you should see all of the AV-Plate. When setting up a Bassboat we use the Pad bottom in relation to the Propshaft ceterline insted of the AV-plate for referencing set-up due to the distance the gearcase is on a stepped hull and/or jackplate.
We Run a 200HO on an 18' 6" Ranger and a 24P in 3-bld is all it will handle but I believe your gear ratio is 2:1, not 1.86:1 as the 200HO Rude is so your prop is turning a bit slower at the same RPM.
I know most are turning 24-25P on the XR6's on the 17-4 to 17-8 bassboat hulls.
 
Top