Forum -> Not-So-Modern
Search Topic
2011 PX 125 bogging
OP
davo1962
UTC
Member
vespa GTS 300
Joined: UTC
Posts: 26
Location: oxfordshire
 
davo1962
Member
vespa GTS 300
Joined: UTC
Posts: 26
Location: oxfordshire
UTC quote
Hi all
2011 px 125 electric auto lube has running issue, recently had 150 barrel and head fitted , has a 114 main jet in , has now been run in with no problems but lately has started to bog down and the odd backfire. Exhaust is scootopia big box standard looking box , I have replaced all carb gaskets and filters and a general clean but it wasn't dirty , starts good but still has this issue….
@jess avatar
jess
UTC
Petty Tyrant
0:7 and counting
Joined: UTC
Posts: 39622
Location: Bay Area, California
 
jess
Petty Tyrant
@jess avatar
0:7 and counting
Joined: UTC
Posts: 39622
Location: Bay Area, California
UTC quote
Moved to NSM.
@scooterist avatar
scooterist
UTC
Molto Verboso
71' Sprint Veloce , 05' Vespa PX150, 1978 P200E
Joined: UTC
Posts: 1618
Location: Tucson, AZ
 
scooterist
Molto Verboso
@scooterist avatar
71' Sprint Veloce , 05' Vespa PX150, 1978 P200E
Joined: UTC
Posts: 1618
Location: Tucson, AZ
UTC quote
The main jet is too big already. 115main jet comes on a Malossi 166cc kit for instance. You should not be above 105 main jet (my personal opinion). I just refitted my PX back to its original 150 cc cylinder and I am running a Malossi box, 26 carb and a 103 main jet. I just did 58 MPH(GPS) top end tucked down.

My experience with larger main jets have been of bogging down. Try something smaller and work from there.
@kudu avatar
Kudu
UTC
Member
1979 P125X, 1983 P125X America
Joined: UTC
Posts: 25
Location: Florence, Italy
 
Kudu
Member
@kudu avatar
1979 P125X, 1983 P125X America
Joined: UTC
Posts: 25
Location: Florence, Italy
UTC quote
scooterist wrote:
The main jet is too big already. 115main jet comes on a Malossi 166cc kit for instance. You should not be above 105 main jet (my personal opinion). I just refitted my PX back to its original 150 cc cylinder and I am running a Malossi box, 26 carb and a 103 main jet. I just did 58 MPH(GPS) top end tucked down.

My experience with larger main jets have been of bogging down. Try something smaller and work from there.
I totally agree with Scooterist - I have just installed a BGM177 kit including a new crankshaft and ignition, tried BGM's "recommended" 125 main jet and only had trouble. Went back to the standard settings for a PX200 and never looked back...
Post Reply
Forum -> Not-So-Modern

Modern Vespa is the premier site for modern Vespa and Piaggio scooters. Vespa GTS300, GTS250, GTV, GT200, LX150, LXS, ET4, ET2, MP3, Fuoco, Elettrica and more.

Modern Vespa is made possible by our generous supporters.

Buy Me A Coffee
 
Shop on Amazon with Modern Vespa

Modern Vespa is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com

All Content Copyright 2005-2026 by Modern Vespa.
All Rights Reserved.

[ Time: 0.0075s ][ Queries: 3 (0.0016s) ][ live ][ 339 ][ ThingOne ]