Jump to content

Welcome to TheMalibuCrew!

As a guest, you are welcome to poke around and view the majority of the content that we have to offer, but in order to post, search, contact members, and get full use out of the website you will need to Register for an Account. It's free and it's easy, so don't hesitate to join the TheMalibuCrew Family today!

Carb on a 2000 Sportster LX


Recommended Posts

andybarefoot

Hi All,

New to the group so hello to all.

I’ve had many outboard Flightcraft’s over the years for Barefooting but recently just bought a 2000 Malibu Sportster LX 
 

I was wondering what the factory standard Carb is on this boat? 

My mechanic has told me that the Holley carb on mine is absolutely not correct. He told me that it’s a 4 barrel double pumper and that it’s far too big for that engine. Is he right? 
 

He has talked me into a smaller 4 barrel Holley- single 650 maybe that’s rebuilt. 

cab anyone confirm if this is correct or if we are making a big mistake?

This will be used for Barefooting so speed is a factor.

 

Many Thanks in advance

Andy  
 

 

Link to post

https://performanceimprovements.com/blogs/news/carb-size-matters-what-size-carburetor-do-i-need suggests that a 500 CFM should work, but that may not be available easily, and your cam may be a little sportier than one in a Pontiac.

http://www.superchevy.com/how-to/engines-drivetrain/1601-choosing-the-correct-carburetor-for-five-common-engine-combinations also suggests 500 CFM, then has a specific example of a 350 (5.7L) targeting 325 hp using a 650 CFM holley.  This sounds like a decent choice.

Perhaps something in the 600 to 670 CFM range would work well for you.

Welcome to the crew!  Pictures of the boat?

  • Like 1
Link to post
Michigan boarder

I have run several carbs on my Echelon.  It was pre-vortec but is custom built now.  Here's the scoop:

  • It came stock in 1994 with a 9772 Weber.  That is a 750cfm carb on a pre-Vortec engine producing 265hp.  Yours should produce 320 I think, right?
  • After the rebuild, we dyno'd the engine with 4 different carbs
    • 650 cfm was running a vaccum (carb too small)
    • 750 cfm was good
    • 850 cfm was good
  • I am currently running the 9772 Weber and produced close to 400hp. 

Given all of that, I would not go less than 650 and would likely do 750 and select the right needle & jetting combo.  What model Edlebrock carb are you running?

  • Like 1
Link to post

A carb in the 650 cfm range will work for you and more importantly, make sure it is a marine version.  What is the current carb size and what is driving the change recommendation?

I would research the engine specs, assuming perhaps an Indmar, best bet to ask them.  
 

Edited by Woodski
  • Like 1
Link to post

@andybarefoot Factory carb from Indmar is Holley 4150 - electric choke, vacuum secondaries, not a double pumper. Not sure of the CFM. That's what's on my 99 Sportster and it'll run 49 MPH no problem. ACME 515 prop.

Edited by drh
  • Like 1
Link to post
andybarefoot

Hi folks, 
This has all been unbelievably helpful. 

I've a 660 cfm rebuilt Holley fitted on there now. 
Haven't lake tested. 

Unfortunately there seems to be a whine from the gearbox when I turn her over and give some revs, it's very noticeable. 
You can hear it wind down when you turn the boat off also. 

Not good. 

I'm on the lookout for a rebuilt ZF gearbox in the UK now - not easy to source. 

I could cry haha! 

Andy

Link to post
andybarefoot
On 3/24/2021 at 9:12 PM, JasonK said:

Is your engine an Indmar or did they still offer Mercruiser back then, over there?

It's Indmar Jason - Thanks

 

Link to post
andybarefoot
On 3/24/2021 at 7:48 PM, drh said:

@andybarefoot Factory carb from Indmar is Holley 4150 - electric choke, vacuum secondaries, not a double pumper. Not sure of the CFM. That's what's on my 99 Sportster and it'll run 49 MPH no problem. ACME 515 prop.

Thanks :) 
Yep there's an electric choke 660cfm Holley with electric choke on there now. Sounds good. Haven't lake tested yet though. 
 

Link to post
andybarefoot
On 3/23/2021 at 11:27 AM, Woodski said:

A carb in the 650 cfm range will work for you and more importantly, make sure it is a marine version.  What is the current carb size and what is driving the change recommendation?

I would research the engine specs, assuming perhaps an Indmar, best bet to ask them.  
 

Awesome. Yep it' been replaced now. Single pumper 650 or 666 I believe. Thanks for all the advice. A great help

Link to post
andybarefoot
On 3/23/2021 at 3:51 AM, Michigan boarder said:

I have run several carbs on my Echelon.  It was pre-vortec but is custom built now.  Here's the scoop:

  • It came stock in 1994 with a 9772 Weber.  That is a 750cfm carb on a pre-Vortec engine producing 265hp.  Yours should produce 320 I think, right?
  • After the rebuild, we dyno'd the engine with 4 different carbs
    • 650 cfm was running a vaccum (carb too small)
    • 750 cfm was good
    • 850 cfm was good
  • I am currently running the 9772 Weber and produced close to 400hp. 

Given all of that, I would not go less than 650 and would likely do 750 and select the right needle & jetting combo.  What model Edlebrock carb are you running?

Unreal advice / knowledge. 
So I believe there's a rebuilt single pumping 650/660cfm Holley on there now. 
Hoping we are all good

Link to post

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...