Topic: Adjusting air/fuel mixture

[feliz]

I have a K1,3,4 and usually adjust the air screws after doing the valve and cam chain adjustment but before doing the carb sync and usually adjust by watching a sensitive tach and adjusting each screw for maximum RPM. I find this a pain and rather hit-and-miss, I'm sure two people doing the same thing would end up with different adjustments.

I have two friends, both retired Honda mechanics who have been telling me to stuff a piece of tubing up one of the exhaust pipes, the other end close too but not pointing at your ear and adjust each carb for the best sound, then the next exhaust etc. Today I started doing this, found it rather difficult and after doing two, because it was getting dark I just turned all the screws out one turn and left it, it seemed to run better than it ever has. I was doing my recently purchased K1 and the carbs were so out of sync I adjusted the sync using my Morgan tune first and was doing the air screw last.

Anyway my question is, do you even bother adjusting these screw or just turn them out the recommended number of turns suggested in the manual and if you do adjust them how do you do it. I always find doing these screws the most difficult part of the tuneup. Thanks for any tips/insight.

[Deltarider]

I have two friends, both retired Honda mechanics who have been telling me to stuff a piece of tubing up one of the exhaust pipes, the other end close too but not pointing at your ear and adjust each carb for the best sound, then the next exhaust etc.

My bike is hibernating now but come spring I definitely will try this. I'll also do some tubelistening at idle by bringing a tube in the carb's throat (after temporary removing the paper filter element). Just curiosity. Bikes like when they're listened to. I might become a bikewhisperer.

[tbpmusic]

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Well, since it's the step just before synching, I always just read the gauges/manometers to do those screws, then move on to the synch part.

Maybe that's a little simplistic, but....

bill2

[feliz]

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Well, since it's the step just before synching, I always just read the gauges/manometers to do those screws, then move on to the synch part.

Maybe that's a little simplistic, but....

bill2

I read somewhere were they can be adjusted to maximum vacuum but I've never found it practical, just not sensitive enough at least on my bikes. I can move the screws two turns and not see a change in the manometers which is why I've always used the RPM but even then I can sometimes turn the screw a complete turn and not see a change in RPM. I know a guy who takes his bike to a facility that does emission testing and they put a probe up each pipe and apparently get it right on but it's too pricey for me.

[Deltarider]

I read somewhere were they can be adjusted to maximum vacuum but I've never found it practical, just not sensitive enough at least on my bikes. I can move the screws two turns and not see a change in the manometers which is why I've always used the RPM but even then I can sometimes turn the screw a complete turn and not see a change in RPM.

+1 I've never seen any change in vacuum by turning the air screws.