Post by Striper on Feb 11, 2007 9:20:50 GMT -5
I installed Boyesen power reeds in my mercury and picked up about 400 rpms. That put me at 5750 my redline is 5250 according to my manual. I have a 26 pitch Laser II. I had a buddy tell me to get my prop repitched to a 27 and have my tips double cupped?
I don't even know what that means. What is you opinon on this? What about a jack plate? are they really beneficial? MY boat is a Nitro 700LX with a Merc. 125. Any help you or anyone can provide would be appreciated. Thanks Terry
Terry I hope you dont mind me posting your question up so that maybe some others could read and provide some advice. First and foremost before doing anything I would consult a marine technician far more knowledgable then myself before doing anything.
But I have a few questions and some answers for you. What was your purpose for the power reed, were you have issues with top end speed and fuel consumption?
As for your friends advice on the 27 double cupped, here is what he is talkng about. The 27 reference is to inches but it is in inches traveled per revolution. This is called the pitch, pitch is the theoretical distance a prop would travel in one revolution.
The rule of thumb on pitch is that one inch of pitch equals 100-200 rpm - move up one inch and you would decrease the RPM move down one inch and you increase the RPM.
So by going up in size from a 26 to a 27 your friends advice is to reduce the RPM to keep you away from the redline - but I think that while it will reduce it - it would only drop by at most 200 RPM. But it would still reduce the RPM's.
DOuble Cupped is a term given to when the prop is curved on both the leading edge as well as the tip, a regular cupped blade only has a single curved lip. Cupping can increase your grip for les slip on the water and decreased blow out caused from excess aeration. It will allow you to also run at a higher trim angle and transom mounting.
Now to the jack plate. A jack plate is a hydraulic lift that is independant from your power trim and tilt for better efficiency. You can drop the motor down for improved hole shots or raise it for top end speed and fuel efficency. Typically jack plates set th motor back 5-6" and place the prop in cleaner water.
Now my opinion - since you are looking at $500 - $700 for a jackplate - give or take and a few more for a new prop - call a technician and potentially go on a ride with them so they can get a really good sense for the boats performance. You had mention that the performance of your boat had improved - I think the prop is a good idea if nothing else, but to increase the grip and reduce the RPM's as for the jack plate I am not too sure. But there are smarter people then me regarding the jack plate with your setup.
Terry - I hope if nothing else I have you to understand some of the terminology and equipment. And cann get quite confusing and you can see how some equipment changes have overlapping effects and whats the best combination.
I don't even know what that means. What is you opinon on this? What about a jack plate? are they really beneficial? MY boat is a Nitro 700LX with a Merc. 125. Any help you or anyone can provide would be appreciated. Thanks Terry Terry I hope you dont mind me posting your question up so that maybe some others could read and provide some advice. First and foremost before doing anything I would consult a marine technician far more knowledgable then myself before doing anything.
But I have a few questions and some answers for you. What was your purpose for the power reed, were you have issues with top end speed and fuel consumption?
As for your friends advice on the 27 double cupped, here is what he is talkng about. The 27 reference is to inches but it is in inches traveled per revolution. This is called the pitch, pitch is the theoretical distance a prop would travel in one revolution.
The rule of thumb on pitch is that one inch of pitch equals 100-200 rpm - move up one inch and you would decrease the RPM move down one inch and you increase the RPM.
So by going up in size from a 26 to a 27 your friends advice is to reduce the RPM to keep you away from the redline - but I think that while it will reduce it - it would only drop by at most 200 RPM. But it would still reduce the RPM's.
DOuble Cupped is a term given to when the prop is curved on both the leading edge as well as the tip, a regular cupped blade only has a single curved lip. Cupping can increase your grip for les slip on the water and decreased blow out caused from excess aeration. It will allow you to also run at a higher trim angle and transom mounting.
Now to the jack plate. A jack plate is a hydraulic lift that is independant from your power trim and tilt for better efficiency. You can drop the motor down for improved hole shots or raise it for top end speed and fuel efficency. Typically jack plates set th motor back 5-6" and place the prop in cleaner water.
Now my opinion - since you are looking at $500 - $700 for a jackplate - give or take and a few more for a new prop - call a technician and potentially go on a ride with them so they can get a really good sense for the boats performance. You had mention that the performance of your boat had improved - I think the prop is a good idea if nothing else, but to increase the grip and reduce the RPM's as for the jack plate I am not too sure. But there are smarter people then me regarding the jack plate with your setup.
Terry - I hope if nothing else I have you to understand some of the terminology and equipment. And cann get quite confusing and you can see how some equipment changes have overlapping effects and whats the best combination.
