Prop Slip Where to start Diagnosis
10-17-2014, 02:48 PM
#41
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10-17-2014, 02:50 PM
#42
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Thread Starter
No worries its quite common for rookies like me to ask OSO for advice only to learn it was an obvious issue. Heck I towed my boat to work with my E brake on once, wondering why it felt so heavy.
Back in the day the dock boys at Shooters in Ft Lauderdale wouldn't let us raft up on our own, they made us throw them our lines from 10 feet out LMAO.
It was like a smash up derby when we arrived. Sometimes I'm sure I am going to make it on OSO as a friggin you tube clip at the launch ramp.
Back in the day the dock boys at Shooters in Ft Lauderdale wouldn't let us raft up on our own, they made us throw them our lines from 10 feet out LMAO.
It was like a smash up derby when we arrived. Sometimes I'm sure I am going to make it on OSO as a friggin you tube clip at the launch ramp.
Last edited by stimleck; 10-17-2014 at 02:53 PM.
10-17-2014, 03:55 PM
#44
Just a few more comments to help focus your troubleshooting direction.
First you are able to run 5000 rpm, so we know the motor is operating correctly for the most part. You witnessed the fact that increasing from a 19" Enertia to a 22" Enertia brought the rpms down. That is a good start.
The problem is getting your power, however much it is, from the motor to the water. From the picture I saw it 'appears' the hull and drive are in reasonable condition. So let's assume that is not holding you back significantly.
I believe the Enertia prop is your first and foremost issue. It has a small blade area and is causing your slip numbers. For an extremely crude analogy, think of using your hand as a paddle in a canoe and you paddle like a monkey on crack. You probably won't go very fast. Say I place an oar in you hand and you do the same. You'd probably be hauling the mail so to speak. So it is with the Enertia prop and your particular combination.
One thing to be careful of when drawing conclusions about how much pitch to drop or increase when going from a 3 blade to 4 blade prop is that is assuming the same prop blade shape/surface area is used between the two prop types. In reality that is rarely the case.
I go back to my previous comments and suggest trying a Rev 4 prop in the 21"-23" range, and perhaps a Bravo 1 in 22-24" pitch, and lastly a Mirage Plus (or Mirage if that's all you can find) in the 21-23" range. All those props will have a larger diameter and will help carry the load, torque, and HP better.
Get good rpm and GPS readings. No iPhone GPS etc, just a good handheld Garmin or the like. Take rpm and mph readings from idle to WOT in 200 rpm increments. Report back and we can go from there.
I wish you luck.
First you are able to run 5000 rpm, so we know the motor is operating correctly for the most part. You witnessed the fact that increasing from a 19" Enertia to a 22" Enertia brought the rpms down. That is a good start.
The problem is getting your power, however much it is, from the motor to the water. From the picture I saw it 'appears' the hull and drive are in reasonable condition. So let's assume that is not holding you back significantly.
I believe the Enertia prop is your first and foremost issue. It has a small blade area and is causing your slip numbers. For an extremely crude analogy, think of using your hand as a paddle in a canoe and you paddle like a monkey on crack. You probably won't go very fast. Say I place an oar in you hand and you do the same. You'd probably be hauling the mail so to speak. So it is with the Enertia prop and your particular combination.
One thing to be careful of when drawing conclusions about how much pitch to drop or increase when going from a 3 blade to 4 blade prop is that is assuming the same prop blade shape/surface area is used between the two prop types. In reality that is rarely the case.
I go back to my previous comments and suggest trying a Rev 4 prop in the 21"-23" range, and perhaps a Bravo 1 in 22-24" pitch, and lastly a Mirage Plus (or Mirage if that's all you can find) in the 21-23" range. All those props will have a larger diameter and will help carry the load, torque, and HP better.
Get good rpm and GPS readings. No iPhone GPS etc, just a good handheld Garmin or the like. Take rpm and mph readings from idle to WOT in 200 rpm increments. Report back and we can go from there.
I wish you luck.
10-17-2014, 07:34 PM
#45
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Thread Starter
[QUOTE=Trash;4204882]Just a few more comments to help focus your troubleshooting direction.
First you are able to run 5000 rpm, so we know the motor is operating correctly for the most part. You witnessed the fact that increasing from a 19" Enertia to a 22" Enertia brought the rpms down. That is a good start.
The problem is getting your power, however much it is, from the motor to the water. From the picture I saw it 'appears' the hull and drive are in reasonable condition. So let's assume that is not holding you back significantly.
I believe the Enertia prop is your first and foremost issue. It has a small blade area and is causing your slip numbers. For an extremely crude analogy, think of using your hand as a paddle in a canoe and you paddle like a monkey on crack. You probably won't go very fast. Say I place an oar in you hand and you do the same. You'd probably be hauling the mail so to speak. So it is with the Enertia prop and your particular combination.
One thing to be careful of when drawing conclusions about how much pitch to drop or increase when going from a 3 blade to 4 blade prop is that is assuming the same prop blade shape/surface area is used between the two prop types. In reality that is rarely the case.
I go back to my previous comments and suggest trying a Rev 4 prop in the 21"-23" range, and perhaps a Bravo 1 in 22-24" pitch, and lastly a Mirage Plus (or Mirage if that's all you can find) in the 21-23" range. All those props will have a larger diameter and will help carry the load, torque, and HP better.
Get good rpm and GPS readings. No iPhone GPS etc, just a good handheld Garmin or the like. Take rpm and mph readings from idle to WOT in 200 rpm increments. Report back and we can go from there.
I wish you luck
Thanks this sound like a logical approach, too bad it will have to wait until spring because I am in Canada.
First you are able to run 5000 rpm, so we know the motor is operating correctly for the most part. You witnessed the fact that increasing from a 19" Enertia to a 22" Enertia brought the rpms down. That is a good start.
The problem is getting your power, however much it is, from the motor to the water. From the picture I saw it 'appears' the hull and drive are in reasonable condition. So let's assume that is not holding you back significantly.
I believe the Enertia prop is your first and foremost issue. It has a small blade area and is causing your slip numbers. For an extremely crude analogy, think of using your hand as a paddle in a canoe and you paddle like a monkey on crack. You probably won't go very fast. Say I place an oar in you hand and you do the same. You'd probably be hauling the mail so to speak. So it is with the Enertia prop and your particular combination.
One thing to be careful of when drawing conclusions about how much pitch to drop or increase when going from a 3 blade to 4 blade prop is that is assuming the same prop blade shape/surface area is used between the two prop types. In reality that is rarely the case.
I go back to my previous comments and suggest trying a Rev 4 prop in the 21"-23" range, and perhaps a Bravo 1 in 22-24" pitch, and lastly a Mirage Plus (or Mirage if that's all you can find) in the 21-23" range. All those props will have a larger diameter and will help carry the load, torque, and HP better.
Get good rpm and GPS readings. No iPhone GPS etc, just a good handheld Garmin or the like. Take rpm and mph readings from idle to WOT in 200 rpm increments. Report back and we can go from there.
I wish you luck
Thanks this sound like a logical approach, too bad it will have to wait until spring because I am in Canada.
10-17-2014, 08:10 PM
#46
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Has about 4 layers bottom paint, partially covered with tremclad rolled on by the idiot ex owner that didnt like the green bottom paint. Can bottom paint have a significant impact
__________________________________________________ ____________________________________
A dirty bottom can cause up to 8 mph loss or more if bad enough.
The Hull is a 21 degree and likely has a hook because its not a speed boat
__________________________________________________ _____________________________________
A hook probably not but look at the very tips of the hull next to the transom.you will probably find built in tabs on the hull bottom...Wellcraft did this on number of there smaller boat..not sayin your is small
__________________________________________________ ________________________________________
Original prop was a 19 mirage-It would cavitate under hard acceleration and hard turns and over rev the motor
I tried an Enertia 22 pitch 13.5 diameter and hit 50 @ 4750 rpm-all pvs holes plugged
I tried an Enertia 21 pitch 13.5 diameter and hit 50 @ 5000 rpm-all pvs holes plugged
(these are listed as bravo 1 compatible, Eco is the outboard version)
I tried a 21 High Five with no pvs plugs and it blew out at 2500 rpm
I tried a 19 pitch 4 blade bravo knock off (I think its a 15" diameter) that had slightly better low end and better lift but hit a rock before I topped it out...
that was your one starting point.....
__________________________________________________ __________________________________________
All small runabout prop's.....try a rev4 as mentioned above. If the boat does indeed have the built in tabs your looking for as much sternlift as you can get to get it off those tabs...large diameter props are going to win the day..Right now based on everything you've stated your starting from scratch.
__________________________________________________ ____________________________________
A dirty bottom can cause up to 8 mph loss or more if bad enough.
The Hull is a 21 degree and likely has a hook because its not a speed boat
__________________________________________________ _____________________________________
A hook probably not but look at the very tips of the hull next to the transom.you will probably find built in tabs on the hull bottom...Wellcraft did this on number of there smaller boat..not sayin your is small
__________________________________________________ ________________________________________
Original prop was a 19 mirage-It would cavitate under hard acceleration and hard turns and over rev the motor
I tried an Enertia 22 pitch 13.5 diameter and hit 50 @ 4750 rpm-all pvs holes plugged
I tried an Enertia 21 pitch 13.5 diameter and hit 50 @ 5000 rpm-all pvs holes plugged
(these are listed as bravo 1 compatible, Eco is the outboard version)
I tried a 21 High Five with no pvs plugs and it blew out at 2500 rpm
I tried a 19 pitch 4 blade bravo knock off (I think its a 15" diameter) that had slightly better low end and better lift but hit a rock before I topped it out...
that was your one starting point.....__________________________________________________ __________________________________________
All small runabout prop's.....try a rev4 as mentioned above. If the boat does indeed have the built in tabs your looking for as much sternlift as you can get to get it off those tabs...large diameter props are going to win the day..Right now based on everything you've stated your starting from scratch.
Last edited by Pliant; 10-18-2014 at 11:46 AM.
10-18-2014, 12:27 AM
#47
Registered
I think the bottom is in rough shape. get a expert to look at it. If you are in socal I could do it. I can bluieprint etc. Also check the compression in the motor. If they are not all the same, that is also a problem. But the prop slip i believe might be bottom related
10-18-2014, 12:14 PM
#48
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The Hull is a 21 degree and likely has a hook because its not a speed boat
Has about 4 layers bottom paint, partially covered with tremclad rolled on by the idiot ex owner that didnt like the green bottom paint. Can bottom paint have a significant impact?
BINGO This is the problem
Get a da sander and an air compressor. These can be rented. Get it off the trailer on some jack stands.
sand all that paint off till you start seeing the original gelcoat with something like 80 grit. Hold the da flat. Then go after it with some 180 to get the rest off. Then put a light coat of spray can dust it on over all of it . Like a popcorn dry coat that covers mostly. Then da that off with some 320. Then go after all of it with some 600. You should have enough gelcoat to take all of this. You will gain about 5 mph.and loose prop slip. Also if there is waves in the botom that could be another 3-5 mph. So realisticly you could be going 60.
Has about 4 layers bottom paint, partially covered with tremclad rolled on by the idiot ex owner that didnt like the green bottom paint. Can bottom paint have a significant impact?
BINGO This is the problem
Get a da sander and an air compressor. These can be rented. Get it off the trailer on some jack stands.
sand all that paint off till you start seeing the original gelcoat with something like 80 grit. Hold the da flat. Then go after it with some 180 to get the rest off. Then put a light coat of spray can dust it on over all of it . Like a popcorn dry coat that covers mostly. Then da that off with some 320. Then go after all of it with some 600. You should have enough gelcoat to take all of this. You will gain about 5 mph.and loose prop slip. Also if there is waves in the botom that could be another 3-5 mph. So realisticly you could be going 60.
10-18-2014, 02:12 PM
#49
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Thread Starter
Well I found lots of foam but it was bone dry in the area that I cored. Based on the care the previous owner took I bet that its wet near the bottom. When I did my last boat it wicked to the top I didn't check for hook yet because its pissing rain, i will tomorrow.
Some of you referenced the boat in my pic but that was just a photo of the same type of boat which shows how low the drive sits. This is my actual boat and my copilot, the boat does have trim tabs not molded in tabs
While I am at it here are some before and afters of my little learning experience or as Phil says "a complete ground up restoration"
I tweaked the interior vinyl, added a great system stripped and painted drive, painted some accessories, new snap in carpet new covers, added a wrap, added pop up hardware, Full Resto by up yurs boat shop
[ATTACH=CONFIG]531169[/ATTACH][ATTACH=CONFIG]531170[/ATTACH][ATTACH=CONFIG]531171[/ATTACH][ATTACH=CONFIG]531172[/ATTACH][ATTACH=CONFIG]531173[/ATTACH][ATTACH=CONFIG]531174[/ATTACH][ATTACH=CONFIG]531175[/ATTACH][ATTACH=CONFIG]531176[/ATTACH][ATTACH=CONFIG]531177[/ATTACH][ATTACH=CONFIG]531178[/ATTACH]
Some of you referenced the boat in my pic but that was just a photo of the same type of boat which shows how low the drive sits. This is my actual boat and my copilot, the boat does have trim tabs not molded in tabs
While I am at it here are some before and afters of my little learning experience or as Phil says "a complete ground up restoration"
I tweaked the interior vinyl, added a great system stripped and painted drive, painted some accessories, new snap in carpet new covers, added a wrap, added pop up hardware, Full Resto by up yurs boat shop
[ATTACH=CONFIG]531169[/ATTACH][ATTACH=CONFIG]531170[/ATTACH][ATTACH=CONFIG]531171[/ATTACH][ATTACH=CONFIG]531172[/ATTACH][ATTACH=CONFIG]531173[/ATTACH][ATTACH=CONFIG]531174[/ATTACH][ATTACH=CONFIG]531175[/ATTACH][ATTACH=CONFIG]531176[/ATTACH][ATTACH=CONFIG]531177[/ATTACH][ATTACH=CONFIG]531178[/ATTACH]
Last edited by stimleck; 10-18-2014 at 02:38 PM.
10-21-2014, 11:22 AM
#50
Registered
Maybe this prop slip issue is enough to just dump the boat and get something else.... Let me know, I want it 
Nice looking boat and great for family with a little performance to boot!
Good luck with the slip issue. Sounds like a lot of good help coming in here.
Nice looking boat and great for family with a little performance to boot!
Good luck with the slip issue. Sounds like a lot of good help coming in here.
