carbs balancing problem

[luke]

Hi!

I've stuck with autumn service works due to a problem with balancing.

Spark plugs changed, tappets checked, aligned. Pilot screws turned counter clockwise 180 degrees - spark plugs color indicated lean mixture.

Then i've moved to balancing carbs, and here the problem is.

Front carb sucked a lot more. Turning adjusting screw clockwise made the front carb vacum to decrease (sloowly both readings from mannometer were reaching the same point), BUT in the same time rpm's were increasing, idle speed adjusting screw almost taken out, but more tweaking the adjusting screw, rpm's were higher, hitting 4 000 rpm.
Turning adjusting screw counter clockwise made rpm's to decrease, but vacum from front carb increase at the same time.

Do you guys see where i've made a mistake or where the problem is?

[slug]

hi luke.worth. check you carb diaphragms one may be slit on one set of carbs.. ,or not seating correctly
may be messing with you air fuel mix .any other gurus any ideas..

[gills]

I'd agree that it sounds like something fundamentally wrong in the carbs. Time to get them off and strip them down: hawkgtforum.com/forum/showthread.php?t=4844. It's a bit time consuming but generally well worth getting them sorted.

[numpty]

Before you do start ripping the carbs to pieces have a VERY close inspection of your carb to head intake rubbers. These can look in good condition but often go hard and don`t seal properly or have miniscule cracks in them which lets air through. This can lead to all sorts of weird running problems, even though the rubbers look in perfectly good condition. Try starting the bike and letting it tick over and put a few quick sprays of something flammable like GT85 directly onto the rubbers. If you hear the revs rise and fall as you do it, there is a leak there.