nc30 odd revs

[Deviant400]

Hi all , took me carbs off the 30 yesterday (i was replacing the vac hose with a thin braided fuel line i had lying about ) pulled the old hose off and bugger it i couldnt reach in to put the new one on , had no long nose pliers to hand or anything to reach in , so i thought sod it ill wip the carbs off , sorted the pipe put carbs back on , now when i rev the bike or ride, the revs tend to hang on a bit , throttle used to blip up and revs dropped back down quick before. now there not so quick to drop down, i used to rely on a wee bit of engine breakin when i shut the throttle on certain bends on my way to work but as the revs hang a bit the ride has become some what different, any thought on what ive done here , its really pissin me off , carbs are all set down firmly and done up good n tight, in fact i think there seated better than they were b4, is it a simple matter of re-balancing (do they need to be redone each time they come off) or could it be something else , any help on this would be of much help

[Cammo]

It's usually pilot screw settings that will cause this, but it is a bit odd if you didn't adjust anything on the carbs.

Take them off again and check them. 2.5 turns out is standard, 2.25 out if you run anaftermarket pipe/exhaust.

[Deviant400]

yeah it is a bit odd , i defo didnt touch anything just took them off the bike , i did remove throttle cables and choke cable but they are back as they were , throttle snaps shut ok, i am puzzled on this one , ill get them off when i get a chance tiz buggin me big time

[Deviant400]

ive just noticed theres snow flakes floatin about the page arrrrh

[arsey30]

May be an air leak, did the carbs go on the rubbers easily?
Dave.

[Deviant400]

no they were a bitch to get back on

[arsey30]

Then make sure the back edge of the front rubbers are not tucked in, the rear ones are easy to see whilst fitting and when fitted.

They fit easier warmed and with rubber or silicone grease, and will slide on with washing up liquid, but that leaves a white oxidization on the inlet stubs, requiring cleaning when carbs are removed.

Dave.

[Neosophist]

May be an air leak, did the carbs go on the rubbers easily?
Dave.

Already beaten!

It's 99% likely to be an airleak.. especially if your revs are hanging on the way back down.. this is classic 'running lean' symptom (caused by the extra air)

Spraying carb cleaner / easy start around the rubbers while its running usually helps to find air-leaks as the revs will change when it sucks the cleaner in.

[Snap]

Hi all , took me carbs off the 30 yesterday (i was replacing the vac hose with a thin braided fuel line i had lying about ) pulled the old hose off and bugger it i couldnt reach in to put the new one on , had no long nose pliers to hand or anything to reach in , so i thought sod it ill wip the carbs off , sorted the pipe put carbs back on , now when i rev the bike or ride, the revs tend to hang on a bit , throttle used to blip up and revs dropped back down quick before. now there not so quick to drop down, i used to rely on a wee bit of engine breakin when i shut the throttle on certain bends on my way to work but as the revs hang a bit the ride has become some what different, any thought on what ive done here , its really pissin me off , carbs are all set down firmly and done up good n tight, in fact i think there seated better than they were b4, is it a simple matter of re-balancing (do they need to be redone each time they come off) or could it be something else , any help on this would be of much help

Did you sort this out? If so, how? Im having similar problems.

[Deviant400]

No i havnt sorted it yet, however im begining to think its defo fooked carb rubbers as said above possibly an air leak , this im beliving as when the bike is cold the revs drop kinda ok , but as the bike warms up (ie then the carb rubbers soften) the revs hang a little more i think the warmed up rubbers leak more as they become soft , (just an idea at this stage) ill be sending off for new rubbs soon , just need to get crimbo out the way first as its sucked up all my funds at the mo (bahh humbug) then ill be doing the carb mods that dataracer kindly posted up on this section , and valve clearances too while im at it, but i have been scratchin my head a bit over this one , if you get a fix your end id be pleased to know what it was