Curvy idles at 5.000 rpm

Hello there,

I have a curvy 2001 model (55.000 kilometres) which idles/revs itself at 5000 rpm seconds after starting up.
Probably a vacuum leak, but don't know from where. I only figured out it is in the front carb, when I close the upper part (without filter on) with my hand, idle comes down to normal. This means too much air to the mixture (running lean), right?
Carbs cleaned, fuel changed. Checked float level, checked choke cable (o-ring changed), checked spark plug. There are no vacuum lines in the front carb, right? I cannot take out intake boot to check because screws are shield, but can a vacuum leak there cause so much rise to idle?
Suggestions please

Start simple, have you considered adjusting the idle screw? (Located on the L/H side of the bike in the triangle cutout of the frame).

Originally Posted by Noddy

Start simple, have you considered adjusting the idle screw? (Located on the L/H side of the bike in the triangle cutout of the frame).

Off course, it is set to 1400 rpm. When I close the front carb intake with my hand idle is fine, when I take off my hand rpms rising again. I have taking out carbs and disable them numerus times, no luck.

[Grant66]

There are no vacuum lines in the front carb, right?

What do you use to check the carb balance? Front right and in the most inaccessible place Suzuki could find.

Are diaphrams ok?

Originally Posted by Grant66

What do you use to check the carb balance? Front right and in the most inaccessible place Suzuki could find.

I didn't checked carb balance, don't have a gauge available. You reckon that carbs out of balance can cause that? I did messed up with carb synch screw

Air leak... orhow are you for fuel? If your carbs are nearly empty the bike runs lean for a bit before dying. Happened after work today.. bike would not idle and was surging.. Switched to reserve and all was well.

Originally Posted by rb8989

Air leak... orhow are you for fuel? If your carbs are nearly empty the bike runs lean for a bit before dying. Happened after work today.. bike would not idle and was surging.. Switched to reserve and all was well.

5 liter fresh fuel after I cleaned carbs

[Grant66]

Originally Posted by Tsioumas

You reckon that carbs out of balance can cause that?

No. Was just pointing out that the front carb has a vaccum. There should be blanking cap on it.

Originally Posted by Grant66

No. Was just pointing out that the front carb has a vaccum. There should be blanking cap on it.

Oupps, I know that, but no line