Author Topic: cb550 idle screw adjustment limits  (Read 1089 times)

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Offline xruss

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cb550 idle screw adjustment limits
« on: September 03, 2015, 08:02:08 AM »
I'm having issues with the idle adjustment screw on a 76 cb550. It needs to be cranked in so tightly to get the bike started that I barely have any gap left in the spring, and the tension is so much that I almost can't crank it in that far by hand. Makes me think there must be a way to adjust the mechanism. Any simple trick that I'm overlooking?
1976 cb550k

Offline flybox1

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Re: cb550 idle screw adjustment limits
« Reply #1 on: September 03, 2015, 08:10:13 AM »
Can you re-bench sync your carbs with the idle screw backed out and with a smaller slide gap (use a thinner drill bit) ?
I dont know if you have carbs with a 'fixed' slide.  usually #2.
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

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Offline xruss

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Re: cb550 idle screw adjustment limits
« Reply #2 on: September 03, 2015, 08:45:54 AM »
Hoping to find a solution that doesn't involve pulling the carb bank off the bike. Seems like there should be a way to make an adjustment while they remain fitted.
1976 cb550k

Offline Duanob

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Re: cb550 idle screw adjustment limits
« Reply #3 on: September 03, 2015, 09:23:29 AM »
Hoping to find a solution that doesn't involve pulling the carb bank off the bike. Seems like there should be a way to make an adjustment while they remain fitted.

If you have small hands you could try a bench sync on the bike. You will have to take the airbox and rubbers off of course. By that time it doesn't take much more to just take the carb rack off. Just remove the cables and the intake bolts and pull the rack back and twist down and slide out to the left. Use a 1/16" drill bit and like Fly says back the idle screw out where it doesn't touch anything before adjusting the slides. 
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1976 CB550F2 Barn Find
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Offline BomberMann650

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Re: cb550 idle screw adjustment limits
« Reply #4 on: September 03, 2015, 10:54:50 PM »
I don't know why you would want to use the idle screw adjustment to start your bike.  Choke and a little throttle usually get mine started in a jiffy.

+1 what flybox said.

and with the right wrenches you can (and ultimately will) do a sync with the carbs on the bike.