CX500 GL500 650 Global

When balancing dual carburetors on an air-cooled VW, typical procedure is to first adjust the respective throttle plate gaps using a "feeler" gauge, and then equalize the carbs while the motor is running using some kind of vacuum gauge. That adjustment includes both the individual throttle screws and the air/fuel mixture screw for each carburetor. Sometimes you need to go around and around with these two screws until you achieve a compromised balance.

I assume that the CX balancing protocol-- which seems entirely a matter of throttle plate alignment using the special balancing screw-- is better, or at least more simple than the above method: however, since fuel enters the carburetors at different rates depending on where the carb is in relation to the fuel supply T junction, doesn't it seem like the mixture adjustment might be a good way to address any imbalance in relative carburetor fuel supply?

I realize that: 1) The previous sentence was much too long, (but hey, I'm from Kentucky); 2) the Throttle plate position determines carb fuel intake (by changing the air pressure in the venturi) as well as air intake; 3) There are some basic differences in CV and non-CV carburetors that could determine the proper method of balancing each; 4) This might be a silly question for someone who understands carburetors better than I do, and, 5) I should have performed a search on this topic before posting my question. If so, my apologies.

If you have an opinion on any of the above 1-5, or anything else related to balancing cv carbs. I'd love to be illuminated.

Stuart

I adhere to the instructions that came with my CarbTune 2 by,"John Morgan" whose business is carburettor baancing,

http://www.carbtune.co.uk/index.html
http://www.carbtune.co.uk/carbcust.html

I have never concerned myself with anything other than using the adjustment screw on these carburettors and have always had a full power band.I even went as far as to ask my local MOT(Road Worthiness Certificate in the UK Ministry Of Transport) to check them when my certificate was renewed on his exhaust gas analyser/dyno and they were perfect.
I have seen several people post that they balance their carburettors at higher revolutions to suit,they think,their most commonly used speed.This is unfortunately bogus.Vacuum operated Carb balancers are not designed,whether professional or home-made,to balance above a certain vacuum velocity and this is usually set by the restrictors and design of the balancer.
What usually happens with home users is that they get frustrated when they cannot achieve balance at the recommended idle speed( 1100 rpm +/- 100) on these machines.Then they notice that if they rev the bike up the balance starts to even out.They then convince themselves the carbs are now balanced at those revolutions.They are not.
Consider also that if the engine was balanced at these higher revolutions it would not be at lower revolutions so there would be more stress applied to the crank-shaft when it's under load during the lower gear changes when the engine is being asked to create more inertia.
No motorcycle shop I know balances carburettors other than at the maker's recommended idle speed or as per the Service manual specs.In racing this rules do not apply and special Carb balancers are used and these days with fuel injection Laptops/EMUs and software are used along with Exhaust gas analysers.I had some experience of this watching a friend of mine ,"Drag Tuning" his Suzuki GSXR for drag racing using his lap-top.

CX tip:

The stock CX500s in the UK have a rear engine hanger.If you remove the engine bolt and slack off the other two securing bolts you can lift the coils out of the way to make access easier but still allow them to have their wires in for firing.

CX/GL tip:

When getting close to balance set the balance slightly off so that when the adjustment lock nut is tightened it brings them in.This has to be done by guess-work but is easy after a few goes and is much easier than trying to get them even and then losing the balance as the lock nut is tightened.If you have the correct Adjustment tool this may not be required.I don't have that tool hence the preceding sentence.