Author Topic: Carb balancing  (Read 226 times)

Offline oldboy

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Carb balancing
« on: April 06, 2021, 03:23:14 PM »
After cleaning carbs,setting float heights etc on my 500/4 and then promptly forgetting to check the slide opening on the bench, I replaced the carbs and proceeded to balance them without much success, as we all know when pinching up the adjuster lock nuts they go out of sync. With the factory set No.3 adjuster having been moved over the years and not knowing where it should be, I sat and thought about it for a while not wanting to remove the carbs again.
I removed all the tops of the carbs, slackened the adjuster lock nuts and adjusted them all so the slides so they completely shut off. Check they where the same by measuring with a vernier from the tops of the carbs to the tops of the slides. Pinched the lock nuts up and adjusted the throttle stop screw so it just moved the slides up from completely closed. Start it up and apart from some very minor adjustments on two carbs it run sweet as. AND when you blipped  the throttle, it shut off immediate to a tickover without waiting for the revs to drop. To make things easier in the future I replaced the two carb top screws directly under the top frame tube with 4mm bolts.
May not be the factory way of doing things but it worked for me and found it very easy to do.

Offline K2-K6

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Re: Carb balancing
« Reply #1 on: April 07, 2021, 10:13:11 AM »
Nice bit of lateral thinking there.

I do feel that people get themselves in a tangle with gauges on these as it's just as you say in getting them all to the same point of mechanical parity, and in range of the master idle adjustment screw being able to work as it should.

The final Honda adjustment is to tweak each idle circuit airscrew to reach combustion parity for each cylinder as a micrometric "polishing" of tickover refinement.

Offline JezzaPeach

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  • CB500/4 K1 1972 gold
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Re: Carb balancing
« Reply #2 on: April 07, 2021, 12:47:58 PM »
Nice one oldboy.
1972 CB500/4 K1 Gold
Wanted: my 500/4 UGP96M
from 1975-78. Garnet Brown.

 

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