Mariner Pitch help needed

Stuart Ponko

Recruit
Joined
Aug 3, 2009
Messages
1
Good afternoon; I'm looking for some help in selecting the correct prop for a 19' Skeeter bass boat. Currently I'm running a 200 hp Mariner with a 5 blade 12.25x24 SS. At 5800 rpms' the boat will top out at 45 mph. What can I do to increase top end? I feel this boat should run 60 with the right prop. Normally i have one person in the boat with the normal fishing gear. The boat also has a hydraulic jackplate. ANy help would be appreciated. thanks Stuart
 

hwsiii

Commander
Joined
Jan 25, 2009
Messages
2,639
Re: Mariner Pitch help needed

Stuart, I need to know the maximum RPM for your motor and the gear ratio as well as the year of your boat, but it appears to me that you tried the old 2 to 1 high speed prop ratio and I believe you are suffering from major prop slip caused by not enough blade surface area. I also need to know the make and model of prop you are trying as well as is your speed by GPS.
Do me a favor and just fill this out.

Iboats Boat and Motor Info
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 recommended HP for your boat
3. Number of people and gallons of gas normally on boat
4. What do you use the boat for
5. Is it a Deep Vee and if so how many degrees of deadrise
6. Year, make and model of motor
7. 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 and turn the motor until the tape lines up with each other, it is easier if two people do this, so one can watch the prop while the other counts the revolutions of the motor
8. Manufacturer?s recommended Wide Open Throttle (WOT) range
9. Anti-ventilation Plate height above keel of boat if it is an outboard in inches
10. Is it a bass boat or does it have a pad bottom
11. Does it have a hydrafoil, dolefin or trim tabs
12. Make, model, diameter, pitch and whether SS or aluminum prop
13. 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. If you do not have a tach you can buy a Tiny Tach for $ 50
14. Are you at sea level or a higher elevation, give us the elevation in feet
15. Has your motor been tuned up lately and have you checked that the carburetor butterfly is opening all the way, checked compression, and looked at the plugs and checked spark, all of the forgoing could be the reason your prop is not attaining full RPM
16. How long has this prop been on the boat and why, at this time, do you think it is the wrong prop
17. Does the prop show any damage that you can see
18. 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

REMEMBER, The numbers I give you will be NO better than the information you give me

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
 
Joined
Aug 2, 2009
Messages
10
Re: Mariner Pitch help needed

i have a 1989 ranger bass boat with a 200 and i got a 4 blade on mine dont know the pitch but ill check it my boat is heavy it 20 feet and ill run 55 60 at times at 5500 rpm
 
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