A question to Jack221 about The Jack Stackô
Post Reply    Forum -> Not-So-Modern
Author Message
Enthusiast
Vespa PK50XL2 & Vespa PX125 Lusso
Joined: 30 Mar 2020
Posts: 65
Location: Norway
Wed Nov 18, 2020 3:21 am quote
I have a question about theThe Jack Stackô

I have a PX125 Lusso. While waiting for my Polini 177 to be rebored and honed I have put my 20/20 carb and original cylinder back on. It also has a SIP Road exhaust fitted.

What would be a good starting point for The Jack Stackô on this scooter? 120/BE3 and a 102 main?

The only air correctors I have at the moment is 160 and 140. Should I get a 120?

I guess the SIP road needs a couple of numbers up from the original 96.

Undrilled original 20/20 airfilter.
Jet Eye Master
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 2504
Location: London UK
Wed Nov 18, 2020 6:02 am quote
If the Polini 177 is unmodified bolt on, then no need to change the stack. AC140 BE5 125MJ and work down from there. Pilot 45/140 or there abouts but decide that at the end.
Enthusiast
Vespa PK50XL2 & Vespa PX125 Lusso
Joined: 30 Mar 2020
Posts: 65
Location: Norway
Wed Nov 18, 2020 6:10 am quote
The polini is unmodified, but will not be bolted on before spring. When that time comes I will mount the 24/24 carb and jet for that setup. Until then I will be running the Piaggio 125cc cylinder and 20/20 carb.

I was wondering what kind of aprox jetting would be suitable for a standard PX125 with a SIP Road. Everything stock
Jet Eye Master
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 2504
Location: London UK
Wed Nov 18, 2020 6:14 am quote
All stock then full stock jetting will be fine. A few sizes up on the main jet will probably go better but you need to test it to see.
Enthusiast
Vespa PK50XL2 & Vespa PX125 Lusso
Joined: 30 Mar 2020
Posts: 65
Location: Norway
Wed Nov 18, 2020 6:20 am quote
Thanks! Wondered about your jack stack and the need to go down to 120 on the AC
Your Rally Here   vespa scooterwest scooter west Motorsport Scooters   Cool Ass scooter seat cover
Post Reply    Forum -> Not-So-Modern
[ Time: 0.1422s ][ Queries: 25 (0.0488s) ][ Debug on ]