Uncontrolled revving 5K RPM at idle

[Sligeach]

hey guys,
finally got the carbs back on the V4 and got it fired up. it was without the airbox and with a direct continuous petrol supply(funnel and pipe).

when i started the bike the bike revvs up to approx. 5K rpm and holds the revs there.

i checked the butterflies and they are all closed, the slides going in an out no probs, choke isnt sticking, and there are no air leaks around the carb rubbers.

priory the taking the carbs apart the bike was running superb, i only had to do so due to a leak in the plastic y-piece.
because it was running well i didnt bother to adjust the idle just yet.

any ideas from you wise guys and gals?

[royster81]

i checked the butterflies and they are all closed, the slides going in an out no probs, choke isnt sticking, and there are no air leaks around the carb rubbers.

if the idle is adjusted properly and the above checked ,you've got me ...

[Sligeach]

well i am not sure if it is.
it was adjusted to 1,5K RPM, prior to me taking the carbs apart, but i have put them back together and cleaned them spick and span, so i too am stumped, i can usually figure it out by i am stumped by this one

[Cammo]

Did you adjust/move the 2 nuts on the throttle cable (carb side)?

This problem can't be too hard to figure, its either getting too much fuel (through throttle, fuel delivery method) or too much air (no airbox, leaking carb rubber/s).

Shouldn't take too long to find the culprit.

[Sligeach]

Did you adjust/move the 2 nuts on the throttle cable (carb side)?

yes i did but the throttle returns to rest on the idle screw and the cable has slack in it

[Cammo]

hey guys,
finally got the carbs back on the V4 and got it fired up. it was without the airbox and with a direct continuous petrol supply(funnel and pipe).

Any chance you're just fuelling the cr@p out of it?

Without an airbox it will have access to enough air to rev up if you provide the fuel!

Best to try it with the airbox and the tank supplying the fuel and see what happens.

[Sligeach]

Any chance you're just fuelling the cr@p out of it?

Without an airbox it will have access to enough air to rev up if you provide the fuel!

i did actually wonder that myself as just it ran at about 1,5K RPM for a min or so, at which point i got very excited and filler the funnel up with fuel and it took off again. i had wondered if it was just a coincidence tho!

[royster81]

check to see if you can roll the throttle closed ,what i mean is instead on you twisting the throttle anti clock wise to rev the bike up ,twist it clockwise to close the throttle,,i have done this a few times when i have accidentally fitted the cables wrong or balanced the carbs wrong and it would idle fast until i sorted it

[MexicanGringo]

i had the same problem a while ago after taking carbs off and cleaning, problem was after cleaning linkages the butterflys didnt close to previous positions. Try visually adjusting the butterflys by turning the balancing screws so that theyr all closed, shine a light from behind to be sure, while ur at it you may as well put a tiny drill bit between the butterflys and adjust them all the same, but with bit out they should all close completely

[Sligeach]

first of all tried Rhory;s advice on the cables and all was well there.

then tried stickshift's idea for putting on the whole air filter assembly and tank, result was same problem, started up and held revs at 5K RPM

then tired mexican's suggestion of closing all the butterfly valves. i adjusted them turning the carbs upside down and filling the engine intake side of the carbs with fuel and then gently opening them until the fuel seeped out.
replaced the carbs, same problem