Adjusting Carburator?

[DayCruiser]

1990 Mercruiser 3.0 130hp with regular Carb.<br /><br />I have adjusted carbs before on other equipment--by ear. Making me think I might be able to adjust carb on boat--if this is the problem.<br /><br />When put in neutral engine will idle for about 10 seconds before slowly losing power and dieing.<br />I made a thread about it being hard to start after warmup awhile back. I remedied this by throtteling all the way up and then starting. This continues to work.<br />It will not idle for long even on initial start up<br /><br />I need to know if there is a set amount to turn the carb screws? Or do it by ear? Which screws do I need to adjust/location? Maybe a pic?<br />Not a fuel injected carb

 

[vicsponjr]

Re: Adjusting Carburator?

I have been having trouble adjusting my carb too, a quadrajet. One thing that was giving me trouble was the throttle cable. You have to adjust the carb with the cable disconnected. Then after getting the carb set adjust the cable at the barrel to line up with lever & re-attach. I think the idle screws should be set with a vacuum guage, turn out to best vacuum. And make the changes slowly, give the engine time to adjust to each new setting. If it wasn't a quadrajet I would have rebuilt it already, too many damn parts. I'm no pro, just sharing some of my experiences, hopefully someone will post something good here that I'm missing.

 

[DayCruiser]

Re: Adjusting Carburator?

Thanks for the info vicsponjr. I didn't know it was going to be that complicated. Maybe a job for the shop when winterized?<br />I am going to try a new shop because I got it back from the shop and it was running like this. They had let it idle while repairing other things

 

[Sagabu]

Re: Adjusting Carburator?

Fuel filter , low fuel presure , carb gasket.

 

[Bondo]

Re: Adjusting Carburator?

Vacuum Leak,..????

 

[Don S]

Re: Adjusting Carburator?

Maybe it just needs a tuneup. All the adjustments in the world won't make up for bad plugs, points, condenser, cap, or rotor, or the timing being off.

 

[DayCruiser]

Re: Adjusting Carburator?

I put a new fuel filter in and spark plug wires trying to get it to idle a few weeks ago. I will check all those other things yall suggested before messing with the carb--thanks!