Idle adjustment 5.7 mercarb

[bakerjet]

Is there a place to adjust the idle? it hangs @ 500 rpm's and is hard to start without the warm up lever. would the idle adjustment help with the hard to start issue? should be around 600 rpm's at idle correct?

 

[Lyle29464]

Re: Idle adjustment 5.7 mercarb

you start it just like a car with the same fuel system.

If it has a carb just pump the gas 2 times and hold it about 1/4 open and roll it over. when it hits pull back to an idle. If it sounds like it will die just pump the gas again. The choke should be closed till it starts and then the vacuum will open it just a tad. The cam on the choke will hold the idle a few hundred rpms high untill the engine warms up and releases the coke. It helps if you adjust the throttle so the weight is off the cam and it can open. then it needs to be at the recommend rpm. You have and adjustment that will set the idle before the coke is released and one that will set the idle after. You must pay attention to the cable also. no need to adjust things if the cable is holding it open.

 

[bigdan1]

Re: Idle adjustment 5.7 mercarb

if your idle is at 500RPM when warm sitting in neutral it is low ....

but i doubt that it reallys runs at 500 RPM.....

did you verify with a portable tachometer ?
if definitely runnin at 500 RPM

just turn the screw on the left side of the carb where throttle sits .....
it will raise your idle speed

but be carefull , too much speed will take its toll on your outdrive when getting in gear .....

 

[John_S]

Re: Idle adjustment 5.7 mercarb

Is there a place to adjust the idle? it hangs @ 500 rpm's and is hard to start without the warm up lever. would the idle adjustment help with the hard to start issue? should be around 600 rpm's at idle correct?

For your 1999, it would be T5, which has to be in base mode. Idle rpms is 650, not in gear. Recommend checking timing while in base mode and do idle speed and mixture.

 

[John_S]

Re: Idle adjustment 5.7 mercarb

but i doubt that it reallys runs at 500 RPM.....

FWIW: I was able to get my 5.7L to idle that low with a q-jet or Ed 1409. It may stall in gear, under load, but a motor in good working order can idle that low.

 

[chaparall villain 2]

Re: Idle adjustment 5.7 mercarb

i would set the idle up a little at the throttle lever on carb by turning screw cloclwise untile the idle is around 650 then while it is running locate the idle mixture screws under the front of carb . then start by turning them one at a time about a quarter to a half turn counterclockwise. repeat with the other one . then look at your idle speed again if it goes up then repeat the process . if it goes down then turn them back in the same amount you turned them out and start over in the other direction ... make sure you turn both of them and continue to see what your idle speed does until you gain maximum rpms. good luck ... oh once you get the maximum rpms adjusting the idle misture screws then readjust at throttle lever to 650 rpms