Go Back  Offshoreonly.com > Technical > Prop Talk
Prop feels wrong >

Prop feels wrong

Notices

Prop feels wrong

Thread Tools
 
Old 11-14-2010 | 08:23 AM
  #1  
Thread Starter
Registered
 
Joined: Sep 2010
Posts: 485
Likes: 0
From: Clear Water Beach Florida
Default Prop feels wrong

Hope all is well; I have a 27 baja boss 509 procharged 730 hp and 750 tq......iam currently running a stock bravo 30 prop. and it feels all wrong, slips bad and makes the boat wobble when coming off plane..Im thinking that it may have helped in the killing of my old bravo -1 drive. does anyone have a solution? thanks patrick,
pacalim1965@yaho is offline  
Reply
Old 11-14-2010 | 11:42 AM
  #2  
CB-BLR's Avatar
Chris
 
Joined: Sep 2005
Posts: 1,426
Likes: 1
From: Snohomish, WA
Default

Define wobble...do you mean vibration?

Vibration indicates something is out of balance...your prop?

Have you tried another Bravo prop?
They are generally great all around propellors.

Chris

Last edited by CB-BLR; 11-14-2010 at 11:44 AM.
CB-BLR is offline  
Reply
Old 11-14-2010 | 04:13 PM
  #3  
Registered
 
Joined: Apr 2009
Posts: 1,852
Likes: 1
From: Denmark and hopefully some place nice
Default

Paca

750 tq on a standard single engine bravo is quite a bit for that drive.

A few questions

How deep is your drive, what year is your boat, gear ratio ect. Have you tried a Mirage+? It will have less impact on the drive and not affect the boat as much in terms of prop torque.
If your drive is high, a 5 blade could help with the slip.

Give Bblades a call. It seems to be the way to go.

Happy boating.
A.O. Razor is offline  
Reply
Old 11-14-2010 | 04:23 PM
  #4  
Thread Starter
Registered
 
Joined: Sep 2010
Posts: 485
Likes: 0
From: Clear Water Beach Florida
Default

Chris, I guess you could call it a vibration. I have not tried another prop. I had the boat out all day today...The boat runs great, but i feel the prop slipping after take off and then hooks up and engages and you feel the acceleration.. Mr gadgets built the drive it has about 5 hrs on it . coming off of plane i feel a vibration throughout the boat. should i try a 28? Thanks
pacalim1965@yaho is offline  
Reply
Old 11-14-2010 | 07:28 PM
  #5  
Registered
 
Joined: Dec 2009
Posts: 867
Likes: 0
From: Grain Valley,Mo
Default

Do the u-joints get greased and gimbal bearing
firehawkcat is offline  
Reply
Old 11-14-2010 | 07:55 PM
  #6  
Thread Starter
Registered
 
Joined: Sep 2010
Posts: 485
Likes: 0
From: Clear Water Beach Florida
Default

the u joints are the new sealed type and the gimbal ring gets routine maint.I think its to much prop for the boat
pacalim1965@yaho is offline  
Reply
Old 11-14-2010 | 08:56 PM
  #7  
Registered
 
Joined: Mar 2009
Posts: 1,194
Likes: 1
From: Delaware
Default

Can you pull the rpms that you want with that pitch? A 30p shouldnt be far off based on your boat and power, but that really depends on your engine set up. If you want to spin 6000rpm, it is probably too big.

With a high X, you will have some slip getting on plane. Mine slips pretty bad, the prop blows out at 2000rpm and climbs to 3000-3500 rpm, then the boat just rolls over and goes.

As far as a vibration, could be any number of things that are already mentioned.
Philm is offline  
Reply
Old 11-15-2010 | 06:23 AM
  #8  
Thread Starter
Registered
 
Joined: Sep 2010
Posts: 485
Likes: 0
From: Clear Water Beach Florida
Default

Philm, I think you nailed it. you just described how my boat is reacting. iam not pulling the rpms, im maxing out at 4900. my rev limiter is set at 5800. I think i'll try a 28, or call brett at b blades.. thanks so much for your input. it really puts things into perspective..
pacalim1965@yaho is offline  
Reply
Old 11-15-2010 | 11:53 AM
  #9  
Griff's Avatar
Charter Member # 55
25 Year Member
Charter Member
Super Moderators
 
Joined: Oct 2000
Posts: 20,232
Likes: 2,482
From: Omaha/LOTO
Default

A 2" drop in pitch will gain you about 400rpms. You will have to the 28 prop labbed as well to get the rpms to about 5600.
Griff is offline  
Reply
Old 11-15-2010 | 07:50 PM
  #10  
Registered
 
Joined: Mar 2009
Posts: 1,194
Likes: 1
From: Delaware
Default

Glad I could help. A smaller prop with some labbing for your application will help alot. Griff has the right idea.

I dont know what is causing the vibration you are feeling coming off plane though.
Philm is offline  
Reply


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.