Ah-Ha! on carb adjustment

craig

I'd been fooling around with my idle speed by adjusting the screw that regulates the throttle linkage. I have two carbs. Saw that one screw moved the entire linkage so I ASSumed that it took care of both sides, with other screw on other carb being redundant. Got to a point where I had all kinds of problems with acceleration and smooth get-up. I decided to check balance of carbs and found them way off. Idle screws were re-set and OK, so I just re-set my linkage screws on both carbs to match. Wow (Ah-Ha), runs great. So if this screw is just a "stop" to keep the throttle linkage from going too low in RPM, why do both have to be adjusted the same when one moves the entire linkage to both carbs? Am I missing something?

7/13/168:22 AM

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Lane AndersonMt. Pleasant, SC Supporting Member

Your throttle linkage between the carbs should be disconnected when setting the carbs up. Due to manufacturing differences the idle settings on the carbs may differ a bit. Each end of the throttle linkage should be separately adjusted to connect to the carbs without affecting their settings. If you have the common hex-bar setup, the upright links that connect the arms at the ends of the bar to the carbs are adjustable and will likely have to be set at slightly different lengths. If you have a bell-crank linkage like I do, you will have to adjust each lateral link so that the carbs setting isn't changed when you reconnect the link to the carb.

7/13/169:25 AM

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craig

Thanks Lane, that info I am aware of and when I balanced them using my Uni-Syn, I had the linkage dis-connected. I then adjusted one end to hit right on the connection so both carbs are starting to move at exactly the same time. Given that, if I did everything correctly and I now have a smooth running set up, would adjusting only one of the linkage stops work to move the throttle plates in both carbs together? Or is it necessary to adjust both stops the exact same amount of turns? Somehow adjusting only one of them got my carbs way off balance. I was wondering if something else caused that.