Carburetor issues help

[driver_dav]

First off boat details: Maxum 2100SR with a Mercruiser 350 that was bored .40 over, Alpha One lower unit
Last year I did a full rebuild of my boat engine, pulled the engine tore down the whole thing honed the cylinders, placed new rings, reseated vales and so on. I never touched the carb, I put it all together and it ran fine, this year it only starts and runs with me pouring gas in to the carb barrels, then dies when that gas runs out. I cant identify the carb and have attached images for someone to help identify it, also I need to know where the spring in the attached picture goes, i have a feeling that is causing a problem. The spring was not installed last year, and the issue I had then was it only started with pouring gas in the barrels, also when I put it in gear in the water it dies right away, but does not die in gear outside of the water.
So my question is what does the spring go to? What could cause the engine to die under a heavier load? And what can cause gas not being pulled to the engine? What Carburetor is this? (there is an 8867 market on top back right of the carb but i do not see anything saying Edelbrock)

 

[Bt Doctur]

Carter AFB, Weber maybe, but the spring is a throttle return spring incase the cable should break. do you have a mechanical or electric fuel pump?

 

[keith2k455]

You may want to verify your fuel pump is actually pumping. Gas down the carb throat is basically bypassing the carb...and is pretty dangerous. Keep a fire blanket and/or extinguisher close.

 

[Dogdave]

Clearly not getting fuel through the carb. Have you checked and verified fuel flow to the carb?

 

[Bondo]

First off boat details: Maxum 2100SR with a Mercruiser 350 that was bored .40 over, Alpha One lower unit
Last year I did a full rebuild of my boat engine, pulled the engine tore down the whole thing honed the cylinders, placed new rings, reseated vales and so on. I never touched the carb, I put it all together and it ran fine, this year it only starts and runs with me pouring gas in to the carb barrels, then dies when that gas runs out. I cant identify the carb and have attached images for someone to help identify it, also I need to know where the spring in the attached picture goes, i have a feeling that is causing a problem. The spring was not installed last year, and the issue I had then was it only started with pouring gas in the barrels, also when I put it in gear in the water it dies right away, but does not die in gear outside of the water.
So my question is what does the spring go to? What could cause the engine to die under a heavier load? And what can cause gas not being pulled to the engine? What Carburetor is this? (there is an 8867 market on top back right of the carb but i do not see anything saying Edelbrock)

Ayuh,.... It's the Merc/ Weber Carter clone carb, exactly the same as the Edlebrock carbs, but a Merc/ Weber,....

Disconnect the hose from the fuel tank, where it attaches to the fuel filter, 'n hook up a can of fresh gas, 'n Try it,....
That'll eliminate the tank,...

If it still won't run, test the Fuel Pump,...

 

[driver_dav]

It is a mechanical fuel pump, mounted on the front left of the engine block

 

[Bondo]

It is a mechanical fuel pump, mounted on the front left of the engine block

Ok,... Hook up a short line, 'n fresh gas in a can right to it,....

Disconnect the line at the carb, 'n direct it into a catchcan,....

Turn the motor over, 'n gas from yer fresh gas can, should pump into yer catchcan,....

If it Does, I'm guessin' the carb needs to be torn down, cleaned, 'n rebuilt,....

'n ya mean, the forward starboard corner of the block,....

 

[driver_dav]

Ok,... Hook up a short line, 'n fresh gas in a can right to it,....

Disconnect the line at the carb, 'n direct it into a catchcan,....

Turn the motor over, 'n gas from yer fresh gas can, should pump into yer catchcan,....

If it Does, I'm guessin' the carb needs to be torn down, cleaned, 'n rebuilt,....

'n ya mean, the forward starboard corner of the block,....

thanks, this is my first ever boat and engine rebuild, i'm very familiar with cars and engines just not the old carburetor and mechanical pump style. so i need to learn the terminology as well, i will give that a shot in a couple days when i dont have college and work.
thanks again!

 

[FuelishBehavior]

I had the same type of Carter/Weber carburetor. Mine was a 1993 and the metering rods have small springs that I believe just get worn and there are small mesh screens above the needle valves that get crudded up with sand, dirt and the bad fuel we have today that will cause them to idle very poorly. I rebuilt mine every year until I finally just went and bought the Edelbrock direct replacement carburetor and have never looked back since. I believe small block Mercruisers would use the 600 CFM 1409 and the big blocks used the 750 CFM 1410. However, with a good rebuild kit, they are extremely simple to rebuild. You just need a good Torx head driver set.

 

[driver_dav]

How do i determine exactly what model merc/weber carb this is so i can get a rebuild kit?

 

[Bondo]

How do i determine exactly what model merc/weber carb this is so i can get a rebuild kit?

Ayuh,.... There's numbers stamped in the edge of the carb's forward corner, leadin' face, starboard side at it's base, just under the nut holdin' the carb on,....
Probably a 9600 xxxx

My Guess is, Quicksilver, #809065, or Carter #902-317A, or a carb kit for the edlebrock 1409 will fit, 'n work just Fine,....

 

[driver_dav]

So I removed the carb and cleaned it up, the screen part at the gas inlet had a lot of thick gunk, removed that and cleaned it up, put it back on and it fired up. Couple things though, I closed the two screws on the front and the think still ran for until I killed it which was atleast ten seconds, shouldnt it die sooner because these are the adjustment screws?
once I had the screws backed out a little and had the engine maintaining a good sound the idle was sitting to, at about 1100-1300 rpms, so I tried backing off on the idle screw on the right side of the carb and it started to die, where should I be adjusting this to get the RPM down to about 700-800, that is what I heard was a good speed. Please help some more
Thanks!

 

[Bondo]

Ayuh,.... Did ya tear down the carb, Completely, 'n rebuild it,..??

The mixture screws usually start at 1, 1/2 turns out, 'n get adjusted from there,....

Idle should be 650/ 750 rpms in the water, in gear,...

Timin', 'n all three screws play into the idle speed,...

 

[driver_dav]

Ayuh,.... Did ya tear down the carb, Completely, 'n rebuild it,..??

The mixture screws usually start at 1, 1/2 turns out, 'n get adjusted from there,....

Idle should be 650/ 750 rpms in the water, in gear,...

Timin', 'n all three screws play into the idle speed,...

not completely, I couldn't get the top and bottom sections to separate

 

[joetheis]

sounded like the needle was stuck or that area filled with gunk.
I'd yank the mixture screws out and spray carb. cleanner in there to clean the gunk out, then set them 1 1/2 and go rich from there.
If you got the top off, spray in the main jets also.
Joe
take any advice I give with a can of beer er 2!

 

[Bondo]

not completely, I couldn't get the top and bottom sections to separate

Ayuh,.... Then ya really didn't do much cleanin',......

A Rebuild starts with a Complete disassembly, then cleanin', puttin' back together, tunin', 'n adjustin',.....

Go to the Edlebrock website, in their tech info section is the Bible for our carbs,...
The shop manual for the Performer 1409,...

 

[pro-crastinator]

DId I miss a part of this thread?
Has the mechanical fuel pump been checked - and verified that it is pumping?
Does the mechanical pump have a pushrod - or an arm that contacts the camshaft> If pushrod, could it have been left out on re assembly?

 

[driver_dav]

The pump is working.
I have gotten it to sit and run for a few minutes pretty regular with the adjustment needles sitting at 1.5 turns out from fully closed. The problem is when the engine warms it dies and it will start again, run a few seconds and then die, any idea what would cause that? It is still idling at about 1000-1100 RPM
What should the engine PSI be at?
Also what would be causing white smoke around the top of the engine cant pinpoint it but was not the carb? After it died from getting warm I was down by the engine and seen some white smoke coming from the carb when the engine was off, also some gas was dripping regularly from one of the barrel nozzles?

 

[NHGuy]

You are getting somewhere now.
Next time take a look at the throttle and figure out how to adjust it. It sounds as if you have been adjusting the 2 mixture screws. I'd say to back them out another 1/8 to 1/4 turn.
Then start it, get it a bit warm, at least til the choke opens fully. then start to reduce the engine speed with the THROTTLE adjustment screw. That's the hex head screw on the port side of the carb just below the black plastic throttle link. It's to the right as you face the back of the boat in your pic.
Once you get the engine speed down to 700 +/- 50 rpm, you fine adjust the (2) MIX screws. To do that you'll need to close down each mix screw separately til the engine stumbles, then reopen til it sounds wrong or starts to smoke, then back to about 35 or 40% above the stumble. If it just won't misfire while way open, that's called rich by the way, go half to 2/3 turn up from stumble.

Now, you need to verify your timing. To do that we need to know which ignition you have.
As you adjust timing the engine speed will move, more timing gives more idle speed, less timing reduces rpm. So after your timing is right reset the carb. You will have to go back and forth between the carb and the ignition timing til it's correct cause higher rpm affects timing advance. If you end up advancing timing then lowering the rpm you may need to reset the timing again. While doing all this it's also easier with the carb throttle link disconnected.

 

[driver_dav]

You are getting somewhere now.
Next time take a look at the throttle and figure out how to adjust it. It sounds as if you have been adjusting the 2 mixture screws. I'd say to back them out another 1/8 to 1/4 turn.
Then start it, get it a bit warm, at least til the choke opens fully. then start to reduce the engine speed with the THROTTLE adjustment screw. That's the hex head screw on the port side of the carb just below the black plastic throttle link. It's to the right as you face the back of the boat in your pic.
Once you get the engine speed down to 700 +/- 50 rpm, you fine adjust the (2) MIX screws. To do that you'll need to close down each mix screw separately til the engine stumbles, then reopen til it sounds wrong or starts to smoke, then back to about 35 or 40% above the stumble. If it just won't misfire while way open, that's called rich by the way, go half to 2/3 turn up from stumble.

Now, you need to verify your timing. To do that we need to know which ignition you have.
As you adjust timing the engine speed will move, more timing gives more idle speed, less timing reduces rpm. So after your timing is right reset the carb. You will have to go back and forth between the carb and the ignition timing til it's correct cause higher rpm affects timing advance. If you end up advancing timing then lowering the rpm you may need to reset the timing again. While doing all this it's also easier with the carb throttle link disconnected.

This is very helpful, thanks!
My other part is you mention to get it a bit warm, I can have the engine sit and run solid for a number of minutes (probably 5) then it cuts out and dies, only starts when I put gas straight into the carb then that runs out and dies, wont start again until it cools, what can be causing this?