Go Back  Offshoreonly.com > Technical > General Q & A
30' cat single hp500 WOT 3500 no more? Need help >

30' cat single hp500 WOT 3500 no more? Need help

Notices

30' cat single hp500 WOT 3500 no more? Need help

Thread Tools
 
Old 07-07-2015 | 08:47 AM
  #11  
Thread Starter
Registered
 
Joined: Dec 2010
Posts: 310
Likes: 0
From: Lake Ariel PA
Default

The secondary's are opening, and it get up on plane quick until 3k then falls on its face, fuel is good I put in 100 in each side of 91 non ethanol
tdpb2008 is offline  
Reply
Old 07-07-2015 | 08:49 AM
  #12  
Thread Starter
Registered
 
Joined: Dec 2010
Posts: 310
Likes: 0
From: Lake Ariel PA
Default

We did pump accelerator pump by hand and it did pick up some so I am told the carb is an 850 but I have doubts of that I'm thinking it may have too small of a carb but not sure till I try another
tdpb2008 is offline  
Reply
Old 07-07-2015 | 10:26 AM
  #13  
Registered
 
Joined: Oct 2012
Posts: 1,332
Likes: 2
From: dfw texas
Default

Even with a 750 it shouldnt throw in the towell at 3k sure both bowls have gas in em ?
Better be hanging on when when you throw some enrichment on this at 55mph the speed jumpnmight tangle you in the drive belts or have ya grabbing a handful of distributor cap at wot.
think your onto something though . If you can still see the float levels your on easy street. Hope the engine hatch has been pulled for your convenience ..
airjunky is offline  
Reply
Old 07-07-2015 | 10:33 AM
  #14  
Thread Starter
Registered
 
Joined: Dec 2010
Posts: 310
Likes: 0
From: Lake Ariel PA
Default

We pulled the hatch off and my buddy pumped the accelerator pump and it picked up so I think the carb has something to do with the problem and I do think the prop and drive is a little too tall for the setup in the boat, just need some re assurance and I hope I'm on the right path lol
tdpb2008 is offline  
Reply
Old 07-07-2015 | 12:07 PM
  #15  
Griff's Avatar
Charter Member # 55
25 Year Member
Charter Member
Super Moderators
 
Joined: Oct 2000
Posts: 20,273
Likes: 2,514
From: Omaha/LOTO
Default

Originally Posted by tdpb2008
Checked the tack to a timing light and it's within a 100rpm of each other
What is total timing set at though???
Griff is offline  
Reply
Old 07-07-2015 | 12:50 PM
  #16  
Thread Starter
Registered
 
Joined: Dec 2010
Posts: 310
Likes: 0
From: Lake Ariel PA
Default

I believe he said it was 32*
tdpb2008 is offline  
Reply
Old 07-07-2015 | 01:45 PM
  #17  
Registered
 
Joined: Oct 2012
Posts: 1,332
Likes: 2
From: dfw texas
Default

If your standing on the throttle as its trying to get past 3500rpm you shouldnt be able to pump anything . Might be time for a known good carb swap , you can take a peek at the throttle plate stampings while old one is off.
sounds like someone may of slapped something together to get you in thier old boat
this is a holley double pumper with a r list number true?
airjunky is offline  
Reply
Old 07-07-2015 | 02:12 PM
  #18  
GPM
Registered
20 Year Member
 
Joined: Mar 2004
Posts: 2,697
Likes: 93
From: Pa
Default

Any chance the fuel pump or filter is causing the problem.
GPM is offline  
Reply
Old 07-07-2015 | 02:32 PM
  #19  
SB
Registered
20 Year Member
 
Joined: Nov 2004
Posts: 14,155
Likes: 3,714
From: On A Dirt Floor
Default

Originally Posted by airjunky
If your leaning out its not good for the motor long term
Nor short term.

Many people that sell a boat with a different motor than what they had in it, don't tune it.

Furthermore, how many boats get sold that the owner takes off their fvorite prop and throws ome other on it? A ton.

Even if running good, which it isn't, I'd be verifying carb list # and pulling it apart to see what jetting and etc is in it.

Obviously, checking timing and all other ignition parts too.

Trusting someone or assuming someone left you something correct, is a quick way down misery lane.
SB is offline  
Reply
Old 07-07-2015 | 03:16 PM
  #20  
GPM
Registered
20 Year Member
 
Joined: Mar 2004
Posts: 2,697
Likes: 93
From: Pa
Default

[QUOTE=tdpb2008;4326494]I have a 30' cobra terminator cat I had just bought it has a hp500 500-540hp it has a bravo 1 1.36 ratio and a 26p bravo prop, at WOT I'm getting between 3500-3800 rpm max @ 55-58mph I'm not sure if I have a timing issue fuel issue or if it needs a 1.50 ratio drive it planes out strong then falls on it's face at 3k rpm

Looking for some help

I don't think the 1.50 will fix your engine but I would bet it will be a better all around gear for that application.
GPM 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.