question about carbs

[manxr65]

just want to know something about carbs , got the bike running good now and went out for a good 30mile run yesterday and notice that when you are ride and coming down the gears the bikes idle when you pull the clutch in seems to be a bit higher then slowly drops to normal again.
a friend said is a cv carb and it will do that as the diaphragm come down slow .
my carbs dont have springs but could i add springs and is this right

[Barry]

If you don't have springs then I assume you have flat top Bing CV carbs which never had springs and there is no provision to add them.  You could remove the air inlet ducts and lift the slide with your finger to check how fast they drop. Absence of springs or the effects of the diaphragms are unlikely to be the cause of your slow return to idle unless maybe you have stiffer non oem diaphragms.  This has been covered many times on the forum and it's nearly always that the idle speed has been set too high or with the engine not fully warm after say a min 10 mile ride.  What idle speed did you have after 30 miles ?

[montmil]

Hi there, Manxster

Have you read the thread just south of your posting? "Can't get carburetion right"? There's help for you there.

And a qualified yes; you can add the return springs to your Bings, depending on the carb model. Which Bing CVs do you have? Always helpful to include the bike's year, model equipment and specifics to your query. That helps all of us help you. Thanks.

Monte

[manxr65]

after 30mile it was idle at 1200 ish , im going to check valves and timing again,

[Barry]

1200 rpm is a touch high.  Original specified range is 800 - 1000. Most people tend toward 1000 rpm or maybe 1100 at the very most.

I suspect that if you lower the idle speed a little the problem will go away.