as many of you know i have recently picked up a 81 jag 4000. i got it running and at first it ran good. then i took it to my friends house to let him ride it for the season. well we took it around the lawn tonight to see if it still ran. we started it up and it was running so/so. so we start driving it and it would rocket off the line but if you would let off the gas it would start to bog down and die. we had to work the throttle to get it 2 idle again. even when its idling its not ideling great sometimes misfires. i have cleaned that carb 3 times and everytime i cleaned it spotlesly. also it has new plugs.