Go Back  Offshoreonly.com > Owners Forum > Scarab
Maximum Rpms? >

Maximum Rpms?

Notices

Maximum Rpms?

Thread Tools
 
Old 07-10-2006 | 01:34 PM
  #1  
GK's Avatar
GK
Thread Starter
Platinum Member
 
Joined: Nov 2005
Posts: 204
Likes: 2
From: Tampa, FL/Milwaukee WI
Default Maximum Rpms?

Does anybody know what the maximum RPMs at full throttle a 1999 38' AVS with twin 502's (stock) should be running? I'm getting 4300 and was expecting closer to 5000. Thanks.
GK is offline  
Reply
Old 07-10-2006 | 03:20 PM
  #2  
2 Trick Rick's Avatar
Racer
 
Joined: Aug 2004
Posts: 2,802
Likes: 0
From: Chesterfield, MI
Default Re: Maximum Rpms?

4900/5100 Is what one at the marina is running, 4300 Seems way to low for 502ci engines.
2 Trick Rick is offline  
Reply
Old 07-10-2006 | 03:36 PM
  #3  
BY U BOY's Avatar
Registered
 
Joined: Aug 2005
Posts: 8,779
Likes: 1
From: HOUSTON ,TX
Default Re: Maximum Rpms?

4800 /5150 I Would Not Go More Than 5200. What Props Are You Runnig.
BY U BOY is offline  
Reply
Old 07-10-2006 | 03:56 PM
  #4  
satisfactionII's Avatar
Registered
 
Joined: Jun 2004
Posts: 2,236
Likes: 1
From: GLOC
Default Re: Maximum Rpms?

4900 to 5100 should be well within reach. How many hours on the engines? If you are around 300-375 hours consider haveing the heads reworked. You could have weak valve springs, causing your valves to float and thus you will loose RPM (according the machine shop). I have the same engine and after the new valve springs were installed I got back to 5100 easily. My old valve springs were so weak I could compress them by hand.
satisfactionII is offline  
Reply
Old 07-10-2006 | 04:15 PM
  #5  
GK's Avatar
GK
Thread Starter
Platinum Member
 
Joined: Nov 2005
Posts: 204
Likes: 2
From: Tampa, FL/Milwaukee WI
Default Re: Maximum Rpms?

Thanks, the engines have 500 hrs and I'm running a total stock factory Bravo one set up, nothing fancy in props. The interesting part is the top speed is very good at 72 knots of the GPS.
GK is offline  
Reply
Old 07-10-2006 | 05:26 PM
  #6  
2 Trick Rick's Avatar
Racer
 
Joined: Aug 2004
Posts: 2,802
Likes: 0
From: Chesterfield, MI
Default Re: Maximum Rpms?

Originally Posted by GK
Thanks, the engines have 500 hrs and I'm running a total stock factory Bravo one set up, nothing fancy in props. The interesting part is the top speed is very good at 72 knots of the GPS.

72 Knots? That’s like 82/83mph! You best check your tachometers, Thay may be off
2 Trick Rick is offline  
Reply
Old 07-11-2006 | 08:14 AM
  #7  
GK's Avatar
GK
Thread Starter
Platinum Member
 
Joined: Nov 2005
Posts: 204
Likes: 2
From: Tampa, FL/Milwaukee WI
Default Re: Maximum Rpms?

I had the top end speed confirmed with a hand held GPS in addition to my dash mount still showed 72 knots trimmed out in perfect lake conditions. It just doesn't make sense with stock engines only running at 4300 RPM. I'm planning on sending the boat in for some engine mods at the end of the season and will get the tachs checked.

Thanks for all your feedback!
GK is offline  
Reply
Old 07-11-2006 | 10:56 AM
  #8  
2 Trick Rick's Avatar
Racer
 
Joined: Aug 2004
Posts: 2,802
Likes: 0
From: Chesterfield, MI
Default Re: Maximum Rpms?

Originally Posted by GK
I had the top end speed confirmed with a hand held GPS in addition to my dash mount still showed 72 knots trimmed out in perfect lake conditions. It just doesn't make sense with stock engines only running at 4300 RPM. I'm planning on sending the boat in for some engine mods at the end of the season and will get the tachs checked.

Thanks for all your feedback!

What size props are you running?
2 Trick Rick is offline  
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Elite Carrier Group
Drives and Lower Units
13
01-04-2009 07:45 PM
nautigrafix.com
Drives and Lower Units
3
10-29-2007 12:44 PM
blown formula
General Q & A
11
03-19-2003 09:43 PM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



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.