How do I set fuel/air mixture 3L Holley carb?

[boatdude100]

2007 - new to me Stingray boat GLP-E

Last ditch effort to fix this myself before joining the lineup at dealer which means my "new" boat will be back mid July- August if I'm lucky :-(

Plugs 1 and 4 foul black almost instantly. Previous owner has popped the tamper proof covers and messed with the carb on both sides

****** I would like to see if I can set mixture properly in hopes it will idle well and stop fouling the plugs. No idea how to do this... please help! ******************

What I know:
Plugs 1 and 4 foul black almost instantly.
Some (valve?) noise from cam/lifter cover
Compression is good (160 avg.)
Spark is present on all cylinders, gap set properly .045 on new correct plugs
Idles/shakes rough under 6500 rpm
runs avg temp at plane when warm +175 to 180 or so if gauge is to be believed
Just replaced impeller, half a fin missing. Not found in hoses.

Sigh. so last chance... adjust fuel ratio in hopes cyl 1& 4 are running rich..
Please help and many many thanks to those who have offered suggestions

 

[jimmbo]

Do 1 and 4 share the same half of the carb?

 

[Scott Danforth]

Do 1 and 4 share the same half of the carb?

not on a 3 liter. big ole hole in the top, log plenum and 4 exits into the cylinders

 

[Scott Danforth]

2007 - new to me Stingray boat GLP-E

Last ditch effort to fix this myself before joining the lineup at dealer which means my "new" boat will be back mid July- August if I'm lucky :-(

Plugs 1 and 4 foul black almost instantly. Previous owner has popped the tamper proof covers and messed with the carb on both sides

****** I would like to see if I can set mixture properly in hopes it will idle well and stop fouling the plugs. No idea how to do this... please help! ******************

What I know:
Plugs 1 and 4 foul black almost instantly.
Some (valve?) noise from cam/lifter cover
Compression is good (160 avg.)
Spark is present on all cylinders, gap set properly .045 on new correct plugs
Idles/shakes rough under 6500 rpm
runs avg temp at plane when warm +175 to 180 or so if gauge is to be believed
Just replaced impeller, half a fin missing. Not found in hoses.

Sigh. so last chance... adjust fuel ratio in hopes cyl 1& 4 are running rich..
Please help and many many thanks to those who have offered suggestions

as stated in your other thread. check your gauge.

if 1 and 4 have black, check your valve seals. you may be leaking oil into the combustion chambers

to adjust idle air on a holley 2300 2-barrel. adjust the two idle air screws in the carb base. make sure the blades are centered in the slot. start 1.5 turns out from seated.

to adjust anything above idle. pull the bowl off the carb, and change the jets. also make sure your power valve hasnt gone south.

if you are spinning a 3 liter inline 4 cylinder to 6500 RPM, the valves are smacking the pistons and the pistons are swapping bores. max RPM you can turn the motor before it explodes is 4800 RPM unless you do a lot of work to the motor. they were never meant to spin high RPM I would check your tach. most likely you are set on a 6 cylinder. in that case, you are spinning the motor at 4333 RPM which is just a tad low.

validate your temp gauge.

 

[boatdude100]

BIG correction in the RPM stated...
Idle shakes at 650 RPM. My apologies. not 6500..... long day in the bottom of a boat...

Mixture screws-
I'm sorry, I dont understand the term "make sure the blades are centered in the slot". Kindly elaborate?

Screws: it appears one is on each side of the carb, so as I understand it...
1. Bring each in to seated, then and out 1.5 turns for starters
2. start engine then turn one until it gets better idle then
3. Turn the other until it gets better still?

And valve seals, do I visually examine after removing rocker cover? What am I looking for?

Am I on the right track?
Big thanks!!

 

[Scott Danforth]

Suggest you get a good mechanic.

If you want to do the work yourself:

Rule #1 stay off youtube. Too much wrong information.

There is no easy button

Google Holley blades and center in the idle slots. Look at the Holley tech library

You adjust both screws the same at the same time

Read the tech manual on your carb

Regarding valve seals, you simply replace them. Pull your manifold if you want to inspect if they are leaking. There will be oil residue in the ports

Replacing valve seals is a 2 hour job if you have the tools and training

 

[jimmbo]

On the 2300 the Idle Mixture Screws are on the Metering Block, not the Base

 

[kenny nunez]

1 other thing on a Holley running rich, the gasket between the metering block and main body sometimes will shrink causing fuel transfer ports to cross over.

 

[jimmbo]

Holley Power Valves, on occasion leak, Diaphragm damaged by Backfire. Overall a very simple but good Carb.