changed clip position and needle, still bogging down

Anything related to Lambrettas... ask tech questions, post helpful info, or just read and learn.
User avatar
lammysilver
registered user
Posts: 71
Joined: Tue Nov 10, 2009 11:50 pm
Contact:

28mm del, 42 clubman, old SR kit...

was bogging from idle - 1/4 throttle with:
105 main, 55 pilot, aq264, X2 (clip 2nd from bottom), 40 slide.

first i moved the clip up, leaned off a bit but not massively.

Went ahead and got an X7 and X13 needle, after trying the X7 then fitting the X13 (the leaner of the two) its still bogging down off idle.

I was thinking of trying a leaner slide and pilot maybe?
User avatar
GP Kevo
registered user
Posts: 321
Joined: Wed Mar 11, 2009 7:48 am
Main scooter: 1969 150 DL / GP225 TS1
Location: Warsaw
Contact:

The needle really comes into play between 1/4 and 3/4 throttle so yes, probably a leaner pilot jet will bring results you want.
User avatar
joeythescooterboy
registered user
Posts: 183
Joined: Wed Jan 07, 2009 1:16 am
Location: Chester
Contact:

X13 is richer than the X7 not leaner kid.
Nemo saltat sorbius, nisi infanus est.
RinB
Posts: 317
Joined: Mon Jan 05, 2009 1:43 pm
Main scooter: Reflections in Blue
Location: Grimsby
Contact:

Dont forget the Slide acts in this part of the throttle in the progression period

Try a 45 -50 slide or take 0.5-1mm of the cut out
If its made of Metal Fettle it !!
User avatar
sean brady scooters
Dealer
Posts: 2040
Joined: Mon Jan 05, 2009 12:09 pm
Location: Ripon, North Yorkshire
Contact:

something strikes me as odd here...
if its a 28mm phbh carb then an AQ 264 would not fit in ...so maybe its an AV 264,either that or maybe you have a smaller PHBL carb...?
Sean Brady Scooters - 01765 690 698
User avatar
lammysilver
registered user
Posts: 71
Joined: Tue Nov 10, 2009 11:50 pm
Contact:

yeh X7 the leaner of the two, thats whats in there, and its a AV264... my fingers hit the keys a bit too quick! Apols for any confusion!! :D

To update i Just got a 50 pilot to replace the 55 and ill be trying that later.
User avatar
Diablo
Dealer
Posts: 614
Joined: Wed Jan 07, 2009 12:24 pm
Location: Nuneaton
Contact:

Lee have you tried adjusting your mixture screw?
Most bikes with your set up work well with an x7 needle
User avatar
lammysilver
registered user
Posts: 71
Joined: Tue Nov 10, 2009 11:50 pm
Contact:

Cheers, ill be trying the leaner '50' pilot in there with X7 (clip adjusted to suit), then tweak the air/mixture screw , fingers x'd, sorted.
See how it goes then if needs be i'll take a look at the slide.

Read the post you put up Al, (motocross carb tuner), good one that, I also found this quite helpful... http://www.lambretta.co.uk/downloads/carbsetup.html

Eitherways Al all going good i should be up visiting soon mate.
eibargum
registered user
Posts: 368
Joined: Wed Jan 07, 2009 6:38 pm
Main scooter: Vespa PX210 Polini
Contact:

If all else fails your right to do what R in B [smiffy] suggest,s, only take 0.5mm off at a time, i had to do this on are lass,s 28mm BHPH to get it to run cleanly at the bottom end, but only after i,d try,d everything else, worked a treat :D .
User avatar
Special X
registered user
Posts: 407
Joined: Wed Jan 07, 2009 9:38 am
Main scooter: Lambretta 125 special 230cc
Location: Wakefield
Contact:

45/50 slide (or modify the existing slide) 50/52 idle should sort it along with a bit of tinkering with the mixture screw. 105 seems a tad small on the main . . I'd have reckoned 110 was nearer the mark. Despite what many people will tell you the idle jet affects the mixture right through the range. Also check that the choke is seating correctly and closing right off as these carbs suffer from choke leakage which affects the lower throttle openings badly.

Hope you get it sorted . . there's nothing worse than nagging carb problems.
Post Reply Previous topicNext topic
  • Information
  • Who is online

    Users browsing this forum: No registered users and 10 guests