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82 slight stumble just above idle

Posted: Wed Jun 15, 2011 11:13 pm
by racer59
Hi All, I am new here. I've had my carbs off a couple times now and I still have the same symtoms. As I drive through town at about 2500 rpm the engine has a slight miss. It starts easily, idles well, starting off from a dead stop is a little rough, but it accellerates strong and cruzes nice and smooth on the highway (3000 rpm and above). What the heck gives? Any ideas? Any and all help is appreciated.

Re: 82 slight stumble just above idle

Posted: Thu Jun 16, 2011 3:32 pm
by virgilmobile
Did you do a accurate carb sync?Even a little off (2"difference)is noticeable in the 1000 to 2000 rpm range at low throttle opening.The closer you can get the vacuum at the 1000rpm range,the smoother and more even the cylinders will fire and pull off idle.Carb sync errors are not so apparent above 2500rpm

Re: 82 slight stumble just above idle

Posted: Thu Jun 16, 2011 3:40 pm
by virgilmobile
Did you do a accurate carb sync?Even a little off (2"difference)is noticeable in the 1000 to 2000 rpm range at low throttle opening.The closer you can get the vacuum at the 1000rpm range(0 difference or less than that),the smoother and more even the cylinders will fire and pull off idle.Carb sync errors are not so apparent above 2500rpm.Also float level must be the same for accurate fuel supply.Even if the sync is perfect,if the fuel level is different,one cylinder may be starving for fuel causing uneven power at the crank from each cylinder.Lastly,adjust the valves,gap the plugs,replace the air filter and gas filter.

Re: 82 slight stumble just above idle

Posted: Thu Jun 16, 2011 5:44 pm
by littlebeaver
vacuum advance may not be working proper...