Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

prop problems (Merged Threads & Posts)


davidroy's Avatar
Member

Join Date: May 2006
Posts: 3

05-24-06, 03:04 AM   #1  
prop problems (Merged Threads & Posts)

Help I have 3.0 L mercuiser. 19 ft stingray I recently tuned up my engine and thought i would clean the prop up. I filed the edges to smooth out the dings and nicks now the boat sounds great but is 10 MPH slower did I change the performance of the prop


Last edited by davidroy; 05-24-06 at 07:59 PM.
 
Sponsored Links
bejay's Avatar
Member

Join Date: Dec 2001
Posts: 2,538

05-24-06, 12:26 PM   #2  
probably filing on a prop probably isnt a good idea.

 
davidroy's Avatar
Member

Join Date: May 2006
Posts: 3

05-24-06, 08:05 PM   #3  
Is my prop at fault ?

Help I have 3.0 L mercuiser. 19 ft stingray I recently tuned up my engine and thought i would clean the prop up. I filed the edges to smooth out the dings and nicks now the boat sounds great but is 10 MPH slower did I change the performance of the prop. anyone out there


Last edited by davidroy; 05-25-06 at 12:02 AM.
 
davidroy's Avatar
Member

Join Date: May 2006
Posts: 3

05-25-06, 12:07 AM   #4  
anybody boat problem

--------------------------------------------------------------------------------

Help I have 3.0 L mercruiser. 19 ft stingray I recently tuned up my engine and thought i would clean the prop up. I filed the edges to smooth out the dings and nicks now the boat sounds great but is 10 MPH slower did I change the performance of the prop problem

 
Pwrbait's Avatar
Visiting Guest

Posts: n/a

05-25-06, 03:00 AM   #5  
Pwrbait
You changed it BIG TIME!! A prop is measured in size and pitch, such as 15X20. Which means it's 15 inches in diameter and has a 20 inch pitch. The pitch is the distanch the prop will travel forward (in inches) during one revolution. By filing the nicks out of your prop you've chanced the pitch. Not only will this cause you to go slower (or faster in some cases), but you've significantly changed the load placed on your engine and outdrive. Some props also have a cup or super cup put into the blade tips to improve performance depending on the size of boat and application. You need to take your prop to your loal prop shop to be reworked back to the original dimensions. More than likely it will be cheaper to have this done then to buy a new prop.
Chris

 
oldJoe's Avatar
Member

Join Date: Nov 2004
Posts: 74

05-28-06, 10:00 AM   #6  
Prop?

A service man ground a lot off a prop for me years ago, after I hit a reef. About 1' or more all around about a 12" dia prop.
The loss of thrust area reduced speed and increased engine rpm - pointless effort since the prop was ruined anyway.
Removing nicks with a file without effecting angles of attack should not reduce speed.
I think you should look to your tuneup for the carb adjustment not correct, and swap with the spare prop to be sure.

 
Pwrbait's Avatar
Visiting Guest

Posts: n/a

05-28-06, 10:21 AM   #7  
Pwrbait
David, I posted this la few days ago when you asked about this.
Chris

You changed it BIG TIME!! A prop is measured in size and pitch, such as 15X20. Which means it's 15 inches in diameter and has a 20 inch pitch. The pitch is the distanch the prop will travel forward (in inches) during one revolution. By filing the nicks out of your prop you've chanced the pitch. Not only will this cause you to go slower (or faster in some cases), but you've significantly changed the load placed on your engine and outdrive. Some props also have a cup or super cup put into the blade tips to improve performance depending on the size of boat and application. You need to take your prop to your loal prop shop to be reworked back to the original dimensions. More than likely it will be cheaper to have this done then to buy a new prop.
Chris

 
Sharp Advice's Avatar
Admin, Forums Host & Manager

Join Date: Feb 1998
Posts: 10,440
CAL

05-31-06, 06:25 AM   #8  
Forums Monitors Note

All prior posts on this subject have now been merged together.
Doing so keeps all exchanges of communications together for ease of following along. Kindly use the REPLY button to continue this thread (subject) until completion is accomplished.

Thanks
Web Site Host and Forums Monitor.


Regards and Good Luck.
Web Site Admin, Moderator Hiring Agent, Host and Forums Manager. Energy Conservation Consultant & Natural Gas Appliance Diagnostics and Repair Technician. Fast, Fair, Friendly and Highly Proficient...

Don't Take Freedom For Granted. Thank A Veteran. Need an Employee? Hire a Veteran

Not only is a mind a terrible thing to waste, it's like a parachute.

It doesn't function until it's OPEN.........

Elvis. "The Sun Never Sets On A Legend."

Gun safety is using BOTH hands!

Driving Safety Reminder:
Buckle Up & Drive Safely.
"The Life You Save, May Be Your Own."

 
Ed Imeduc's Avatar
Member

Join Date: Aug 2002
Posts: 18,389
MO

06-02-06, 09:56 PM   #9  
What did the tack say in ####. Like said get a new prop the same size and pitch. If it tacked out ok and did the job for you when you ran the boat.

ED

 
harveje's Avatar
Member

Join Date: Jan 2006
Posts: 122
MS

06-05-06, 03:47 AM   #10  
My 90 3.0 WOT is 44-46K with a 3 blade Al. 19 P I'm in the range and about 42 MPH loaded. With a 4 blade AL 18P in the range and 35-37 MPH loaded.

 
Search this Thread