Null


Pages: [1]

not fast enough

  • Karma: +0/-0
Carb tuning
« on: June 22, 2016, 02:51:42 PM »
Hi guys new to the page just got a jet boat and it has a 454 with a demon 850cfm double pumper. Second pumper wouldn't work on the carb so I rebuilt the carb and fixed the problem but the thing is running was richer than it already was and now is flooding itself and not wanting to start after I stop. Just wondering if anyone has ran this setup and found a jet size that works good before I have to buy a new carburetor. Thanks
Logged
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

Hoofy

  • Karma: +4/-0
Re: Carb tuning
« Reply #1 on: June 22, 2016, 03:08:07 PM »
Check float level

Sent from my SM-G920V using Tapatalk

Logged
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

69kona

  • Karma: +13/-0
Re: Carb tuning
« Reply #2 on: June 22, 2016, 03:10:54 PM »
Are the floats set ...


Sent from my iPhone using SoCal Jet Boats
Logged
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

HubrisHCC

  • Karma: +0/-0
Re: Carb tuning
« Reply #3 on: June 22, 2016, 03:17:57 PM »
3rd on it being a float issue. Possibly some debris caught in the needle and seat.
Logged
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

Hoofy

  • Karma: +4/-0
Re: Carb tuning
« Reply #4 on: June 22, 2016, 03:39:59 PM »
Logged
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

not fast enough

  • Karma: +0/-0
Re: Carb tuning
« Reply #5 on: June 22, 2016, 03:53:09 PM »
Brand new needle and seat floats set in the middle of the eyeglass. I checked that already. Carb was running rich primary to being cleaned out now it is extremely rich


Sent from my iPhone using SoCal Jet Boats
Logged
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

not fast enough

  • Karma: +0/-0
Re: Carb tuning
« Reply #6 on: June 22, 2016, 04:02:57 PM »
I've went through everything and I know the thing needs a rejet. I was just trying to get a baseline of what jet sizes people are running on stock 454's with a 850 carb


Sent from my iPhone using SoCal Jet Boats
Logged
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

HubrisHCC

  • Karma: +0/-0
Re: Carb tuning
« Reply #7 on: June 22, 2016, 05:50:16 PM »
Well don't know if this is gonna help ya or not. I've got a holley 750 on a 502 and I'm pretty sure I'm running .084" jets currently.
Logged
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

Blue2184

  • Karma: +4/-0
Re: Carb tuning
« Reply #8 on: June 22, 2016, 05:58:13 PM »
You prob have the idle cracked open to far and it's pulling fuel from the carb and not the idle circuit... With the carb off the transition slot should be square and not rectangle! It not it will idle so fat it will burn your eyes...


Sent from my shop setting in my boat making motor noises
Logged
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

not fast enough

  • Karma: +0/-0
Re: Carb tuning
« Reply #9 on: June 22, 2016, 06:04:32 PM »

Quote from: HubrisHCC on June 22, 2016, 05:50:16 PM
Well don't know if this is gonna help ya or not. I've got a holley 750 on a 502 and I'm pretty sure I'm running .084" jets currently.

Thank you!


Sent from my iPhone using SoCal Jet Boats
Logged
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

not fast enough

  • Karma: +0/-0
Re: Carb tuning
« Reply #10 on: June 22, 2016, 06:05:56 PM »

Quote from: Blue2184 on June 22, 2016, 05:58:13 PM
You prob have the idle cracked open to far and it's pulling fuel from the carb and not the idle circuit... With the carb off the transition slot should be square and not rectangle! It not it will idle so fat it will burn your eyes...
Hmm we fired it up in the garage last weekend and had to get out because my eyes were watering so bad. I will have to check this out


Sent from my shop setting in my boat making motor noises


Sent from my iPhone using SoCal Jet Boats
Logged
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

crewchief22

  • Karma: +66/-0
Re: Carb tuning
« Reply #11 on: June 22, 2016, 07:13:25 PM »
Usually the factory jetting is going to be pretty close, then only requiring small adjustments for tuning.  If this carb still has the original jetting I'd say you have another issue causing you problems.

Logged
  • Boat #1: '77 Hondo Pantera GT Jet
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party
"Racing is life!  Anything that happens before or after, is just waiting"    Steve McQueen

The problem with America is stupidity. I'm not saying there should be a capital punishment for stupidity, but why don't we just take the safety labels off of everything and let the problem solve itself?

not fast enough

  • Karma: +0/-0
Re: Carb tuning
« Reply #12 on: June 22, 2016, 07:17:58 PM »
But would the factory jetting on an 850 be set up for a stock 454?


Sent from my iPhone using SoCal Jet Boats
Logged
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

crewchief22

  • Karma: +66/-0
Re: Carb tuning
« Reply #13 on: June 22, 2016, 07:21:20 PM »
Quote from: not fast enough on June 22, 2016, 07:17:58 PM
But would the factory jetting on an 850 be set up for a stock 454?

If it was going into a 78 Chevy pick up truck I'd say it was too much, but going into a jet boat it'll be just about right.  It's difficult to over-carb a jet boat.

 

Logged
  • Boat #1: '77 Hondo Pantera GT Jet
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party
"Racing is life!  Anything that happens before or after, is just waiting"    Steve McQueen

The problem with America is stupidity. I'm not saying there should be a capital punishment for stupidity, but why don't we just take the safety labels off of everything and let the problem solve itself?
Pages: [1]
 


Null

SMFPacks CMS 1.0.3 © 2026