Bike Cuts Out While Idling

[GS500-E]

hey guys, when my bike stops for lights or a junction i have to keep it revved myself because if i let it idle it just cuts out, and when im accelerating it usually coughs a few times before accelerating, just got it services so all spark plugs and air filters have been changed etc etc, any ideas? we cleaned out the carbs today but didnt do much, it stopped it from coughing but still cuts out when i stop/idle the bike, any ideas? cheers!

[Rickyz80]

make sure the idle screw :

is screwed in counterclockwise until the idle speed(after warming up) is around 1200.  I'm new but I'm sure that's what everyone else will say here.  I had the same problem and this helped a bit with that problem, although my bike still is running kinda funky and bogging.  But that doesn't have to do with the idle speed. So good luck with that.

[GS500-E]

oh right, thanks very much mate ill give that a go tomrorow after work, hopefully it will be well warmed up by then and well up for working cheers! ill get back to you on how well it goes, thanks!

[GS500-E]

ok have an update on the situation.

bike keeps cutting out randomly now! how strange! ill be going 50 mph down the road then my bike will just slow down and cut out when it gets down the gears. now i have no idea why, there is plenty of fuel in my tank, but when i usually put it onto reserve tank when it cuts out, just incase theres something blocking the main tank or something from fueling the bike? also it first cut out after 80 miles with a full tank, im not sure if i ran outta petrol due to possible un-efficancy from the engine, then i filled it up, and it cut out at 40miles on the speedo. its totally whack! my mechanic serviced the bike, thinking that would fix it. it didnt. then he noticed the throttle cable was pulling, and frayed possibly, so he changed the position of it but he played with the throttle valve, and the idle valve so to keep it from cutting out while idling, he changed the valve settings, but the valve settings make the bike too rich, sounds like the choke is on when it isnt, also my bike is backfiring/coughing alot!!!! normally every start and stop. any ideas? also my mechanic says theres a common fault with gs500's about the vacuum system, says the diaphrams go bad and need replaced, does this sound if i replaced the 2 diaphrams on the carbs that it would fix my problem? ill deeply appreciate all help thanks!

[ohgood]

ok have an update on the situation.

bike keeps cutting out randomly now! how strange! ill be going 50 mph down the road then my bike will just slow down and cut out when it gets down the gears. now i have no idea why, there is plenty of fuel in my tank, but when i usually put it onto reserve tank when it cuts out, just incase theres something blocking the main tank or something from fueling the bike? also it first cut out after 80 miles with a full tank, im not sure if i ran outta petrol due to possible un-efficancy from the engine, then i filled it up, and it cut out at 40miles on the speedo. its totally whack! my mechanic serviced the bike, thinking that would fix it. it didnt. then he noticed the throttle cable was pulling, and frayed possibly, so he changed the position of it but he played with the throttle valve, and the idle valve so to keep it from cutting out while idling, he changed the valve settings, but the valve settings make the bike too rich, sounds like the choke is on when it isnt, also my bike is backfiring/coughing alot!!!! normally every start and stop. any ideas? also my mechanic says theres a common fault with gs500's about the vacuum system, says the diaphrams go bad and need replaced, does this sound if i replaced the 2 diaphrams on the carbs that it would fix my problem? ill deeply appreciate all help thanks!

1) you need a new mechanic. he's guessing at best. sorry.
2) adjusting the valves usually helps smooth things out.
3) adjusting the carb's butterflys will help smooth out idle, but faster revs don't notice it. (UNLESS they're wayyyy out of sync) you can set your carb butterflies with a very thin piece of wire and patience, by eyeballing the butterflies and the wire until it JUST touches both at the same time.
4) change your throttle cable. if it breaks while you're merging / crossing / starting you could be killed or worse !
5) your choke circuit (or just the cable) may need changing also. check for smooth operation at the carbs.
6) the vacuum system isn't known for problems. the carbs ARE however known to be fiddled with by people that shouldn't be fiddling until the bike is unridable
7) there are a couple of folks on the board that will service your carbs completely very cheaply. i'm assuming you're not in the USofA though...
CHECK YOUR PLUG WIRES, they are mistaken for a carburetor problem tons of times. gap your plugs proper, check for good fuel flow (at the float bowl drains), and check your intake boots (between the carbs and the head) aren't leaking air.