Modern Vespa : SI 2424 carb problem

SI 2424 carb problem

OP scooterbug2t UTC details Lurker PK, PX, Bajaj, ET4 Joined: UTC Posts: 1 Location: Kent
OP scooterbug2t Lurker PK, PX, Bajaj, ET4 Joined: UTC Posts: 1 Location: Kent	UTC quote Hi all Got a px, DR180, 24carb, will only start and run if I put my finger over the top of the idle jet? Any clues greatly recieved Cheers

Tierney UTC details Veni, Vidi, Posti Joined: UTC Posts: 7616 Location: Tega Cay, SC
Tierney Veni, Vidi, Posti Joined: UTC Posts: 7616 Location: Tega Cay, SC	UTC quote I maybe have a clue, but why don't you list the all the jets you have in there now.

Ginch UTC details Veni, Vidi, Posti 74 Super, 75 Super, PX project, LML off-roader and '66 Blue Badge Smallframe Joined: UTC Posts: 9005 Location: Ballarat VIC, Australia
Ginch Veni, Vidi, Posti 74 Super, 75 Super, PX project, LML off-roader and '66 Blue Badge Smallframe Joined: UTC Posts: 9005 Location: Ballarat VIC, Australia	UTC quote Has to be too lean. Probably air leak would be my first guess... what have you done previously? Since it was last running ok? And yes, jet sizes please.

rowdyc UTC details Molto Verboso GL, PK, PE200 with hack, Sears Rust Badge Joined: UTC Posts: 1347 Location: Deep in the heart of Texas
rowdyc Molto Verboso GL, PK, PE200 with hack, Sears Rust Badge Joined: UTC Posts: 1347 Location: Deep in the heart of Texas	UTC quote Maybe to lean or wrong type of jets as their are several combinations. To check to see if you have the right type (not size) of idle jet, if your idle jet has a hole in it, the brass fitting to the bottom left should not have a hold. Below is a an example of a idle jet "without a hole" but the brass fitting to the bottom left has a hold.

TCC UTC details Addicted Vespa PX200 Joined: UTC Posts: 621 Location: Sydney, Australia
TCC Addicted Vespa PX200 Joined: UTC Posts: 621 Location: Sydney, Australia	UTC quote Rowdy's put his finger on it (that's not meant to be a joke ). Early Si24/24 carbs are different to later ones. There is a "what to do" to modify the carb to take later jets but I'm blowed if I can find it. I thought it was in the shop manual but no luck. Anyone else help? ⚠️ Last edited by TCC on UTC; edited 3 times

Vader19 UTC details Mr. Clean P,SUPER,V90, 50 Special Joined: UTC Posts: 10205 Location: This is't my locker!
RIP Vader19 Mr. Clean P,SUPER,V90, 50 Special Joined: UTC Posts: 10205 Location: This is't my locker!	UTC quote TCC wrote: There is a "what to do" to modify the carb to take later jets but I'm blowed if I can find it. I thought it was in the shop manual but no luck. Anyone else help? is this what you're thinking of? https://modernvespa.com/forum/post1091443?highlight=#1091443

TCC UTC details Addicted Vespa PX200 Joined: UTC Posts: 621 Location: Sydney, Australia
TCC Addicted Vespa PX200 Joined: UTC Posts: 621 Location: Sydney, Australia	UTC quote Yep, that's it. I'm thinking maybe it's what the OP needs to do.

Ginch

UTC

details

Veni, Vidi, Posti

74 Super, 75 Super, PX project, LML off-roader and '66 Blue Badge Smallframe

Joined: UTC
Posts: 9005
Location: Ballarat VIC, Australia

Ginch

Veni, Vidi, Posti

74 Super, 75 Super, PX project, LML off-roader and '66 Blue Badge Smallframe

Joined: UTC
Posts: 9005
Location: Ballarat VIC, Australia

UTC quote

External inline image provided by member with no explanatory text

Garagerocker wrote:

The older solid slow running jets without the hole was mounted in carbs that had an air intake hole in the carb body. These carbs could be upgraded with the new kind of jets by blocking the hole with a lead shot(see pic) When doing this operation it was adviced to also adjust the idle air/fuel mixture adjusting screw by screwing it a ½ turn out.
Reason for changing this was to prevent the carb from flooding when engine was shut off while parking

I missed that the first time around! Thought maybe that was my issue and ran out to check but I already have the blocked airway. Good tip anyway.[/img]

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