Wont Idle, Carburetor was just rebuilt

[trdexpert]

Hello,
A couple days ago I had my Carburetor completly rebuilt. Today I installed it and its still giving me the same problem. It wont Idle, The Carburetor shop said it was going to be pre adjusted but that I would have to tune it up.
So I started the boat and reved it up I brought it back to neutral to let it idle but it keeped shutting off.
It really smelled like fuel and I noticed black smoke. Is it just running rich? Should I try to tune it up?

The boat is a 1980 Searay with an v8 OMC185
Please help me with Tips and Advice..

Thanks,

Al

 

[trdexpert]

Re: Wont Idle, Carburetor was just rebuilt

Help

 

[Incorrigible]

Re: Wont Idle, Carburetor was just rebuilt

I hear your pain. Sounds like you may have other things going on than just your carb. Do you have adequate fuel TO the carb? Has the engine been properly timed? I'd look into your ignition and your ignition timing as a start. Why did you have the carb rebuilt?

 

[searay3]

Re: Wont Idle, Carburetor was just rebuilt

The carb comes back from the rebuilder with the IDLE AIR ADJUSTMENT screws set to just start the engine. Once the engine starts, open the throttle a tad to let it come up to temp. turn the screws out or in a little until the rpms change. once you have it idleing, even poorly, use the idle speed screw and the mixture (idel air adjustment) screws to reach a smooth idle at the proper rpm. There is no 'set' adjustment. Each engine runs a little different and that is why these screws are there. Turn them in and out and you will see the motor behaving differently. By tuning it, he means the final adjustment needs to made on the running engine. Nothing to take apart.

 

[trdexpert]

Re: Wont Idle, Carburetor was just rebuilt

Yeah I had the carb full rebuilt. I will try messing with adjusment screw today. So when I have it reved up a little that's when I should play with the adjust idle screw right?

 

[searay3]

Re: Wont Idle, Carburetor was just rebuilt

Just remember, once the throttle starts to open there is a point when the idle circuit in the carb is no longer releveant. So just crak the throttle enough with the idle speed screw to keep it running and play with the mixture screw. Then slow it down some with the idle speed screw and play with the mixture again. After a little bit you will be at a smooth idle and proper rpm. This adjustment procedure is only relevant if ign is set properly, dwell if you have points, timing if iether points or electronic.

 

[trdexpert]

Re: Wont Idle, Carburetor was just rebuilt

The carb comes back from the rebuilder with the IDLE AIR ADJUSTMENT screws set to just start the engine. Once the engine starts, open the throttle a tad to let it come up to temp. turn the screws out or in a little until the rpms change. once you have it idleing, even poorly, use the idle speed screw and the mixture (idel air adjustment) screws to reach a smooth idle at the proper rpm. There is no 'set' adjustment. Each engine runs a little different and that is why these screws are there. Turn them in and out and you will see the motor behaving differently. By tuning it, he means the final adjustment needs to made on the running engine. Nothing to take apart.

Thank you, this really helped. Thank u all. So I got running I set the rpms a little higher so that I won't give me problems out in the water..

 

[HT32BSX115]

Re: Wont Idle, Carburetor was just rebuilt

Howdy,


Your float could be stuck and it's dumping copious amounts of fuel into the engine at idle......

...........But I would look at the automatic choke first.

sometimes "rebuilt" carbs need to be rebuilt by someone different.....

 

[willaim]

Re: Wont Idle, Carburetor was just rebuilt

mine done the same thing, I had the carb rebuilt, did not help, I put a fuel pump on it and that cured it.

 

[gdombroski]

Re: Wont Idle, Carburetor was just rebuilt

It really smelled like fuel and I noticed black smoke

Idle mixture screws will contribute to this, but most common cause is choke adjustment. Mine are Holley's here's what they say
CHOKE ADJUSTMENT
1. You can control the choke operation by rotating the choke cap. If the choke comes off too soon, rotate the cap counterclockwise one notch at a time, until the choke operation is satisfactory. Reverse the procedure by loosening the screws, if the choke comes off too late. The choke setting from the factory is on ?index? or at the center position. After making the final adjustments, start the engine and make sure the choke plate opens completely.
A. A choke that comes off too soon could exhibit one or more of the following symptoms: stalling, surging, backfiring, stumbles, or poor vehicle driveability when the vehicle is cold.
B. A choke that comes off too late could exhibit one or more of the following symptoms: black smoke from the tail pipe, poor driveability when cold, poor gas mileage, misses, or rough idle.