Lambretta revving on after clutch is pulled in.

[Chris F]

Question for you. I've got a 24 mil Mikuni on a 200 Sil barrel with a taftspeed mk4. The prob is when pulling in the clutch it's revving on for about 2 to 6 seconds before it drops down enough to shift appropriately. It's not revving it's nuts off like it has an air leak & it doesn't do it all the time, but its enough to be annoying.

Any thoughts / ideas?

Thanks in advance.

[Toddy]

Question for you. I've got a 24 mil Mikuni on a 200 Sil barrel with a taftspeed mk4. The prob is when pulling in the clutch it's revving on for about 2 to 6 seconds before it drops down enough to shift appropriately. It's not revving it's nuts off like it has an air leak & it doesn't do it all the time, but its enough to be annoying.

Any thoughts / ideas?

Thanks in advance.

Throttle cable routing or fraying ? Pilot Jet ??

[Andy Pickering]

Air leak ?

Sent from my GT-I9000 using Tapatalk

[Darrell Taylor]

it might be the clutch isnt disengaging fully/dragging holding up the revs
also piston port motors at high rpm have a habit of holding the slide if the slightest bit tight
u could try richening the mixture screw a turn or a slightly bigger pilot jet just in case its high rpm/small throttle position leaning out.

[Muppet]

it might be the clutch isnt disengaging fully/dragging holding up the revs
also piston port motors at high rpm have a habit of holding the slide if the slightest bit tight
u could try richening the mixture screw a turn or a slightly bigger pilot jet just in case its high rpm/small throttle position leaning out.

would a retro fit power jet help in this situation?

muppet,

[johnd]

it might be the clutch isnt disengaging fully/dragging holding up the revs
also piston port motors at high rpm have a habit of holding the slide if the slightest bit tight
u could try richening the mixture screw a turn or a slightly bigger pilot jet just in case its high rpm/small throttle position leaning out.

My clutch used to do this, it can give you heart failure after a long blat at full throttle!! To make sure that it isn't an air leak or lean part throttle and that it is the clutch, try knocking it in to neutral and see if the revs drop straight away.

[red ghost]

it might be the clutch isnt disengaging fully/dragging holding up the revs
also piston port motors at high rpm have a habit of holding the slide if the slightest bit tight
u could try richening the mixture screw a turn or a slightly bigger pilot jet just in case its high rpm/small throttle position leaning out.

would a retro fit power jet help in this situation?

muppet,

still yet to see a pj on a 24..

and i'd say the carb is lean..

[Darrell Taylor]

it might be the clutch isnt disengaging fully/dragging holding up the revs
also piston port motors at high rpm have a habit of holding the slide if the slightest bit tight
u could try richening the mixture screw a turn or a slightly bigger pilot jet just in case its high rpm/small throttle position leaning out.

would a retro fit power jet help in this situation?

muppet,

the power jet will only draw at wide open throttle or a bit less depending on its fitted location in the venturi so wouldnt help apart from improved slide lubrication if its sticking

[Darrell Taylor]

it might be the clutch isnt disengaging fully/dragging holding up the revs
also piston port motors at high rpm have a habit of holding the slide if the slightest bit tight
u could try richening the mixture screw a turn or a slightly bigger pilot jet just in case its high rpm/small throttle position leaning out.

would a retro fit power jet help in this situation?

muppet,

still yet to see a pj on a 24..

and i'd say the carb is lean..

the pwk is available as a 24mm and 21mm power jet version from the various pwk copy manufacturers although the power jets function is different on most of them as its fitment method varies considerably, some deliver early and some dont deliver until the throttles been open a few seconds