bogging

Anything related to Lambrettas... ask tech questions, post helpful info, or just read and learn.
DaveTomo
registered user
Posts: 395
Joined: Thu Oct 21, 2010 7:50 pm
Main scooter: SX 200
Contact:

Looking for some advice. Set up is race Rapido 225, 50mm Gori exhaust, Delly 30 , 122 main,55 pilot, AV266 X7 second clip,40 slide mixture 3 turns out. Static timing set at 17 BTDC, new BGM billet head, squish set at 1.3. , running at 3% oil Get to about just over half throttle bogs badly.This was the same set up I had last year but with a 48mm clubman and a AF head which ran fine. Changed the jetting to X13 top clip and AV264 no difference.Checked the Indian stator all readings good,checked plug ,HT lead,even bought a new BGM V.3 stator no different as I thought it may be when under load its breaking up.Changed the CDI to a known working one -no different,taken the green off the ignition switch off the CDI to take that out of the circuit -no different.Tried an Amal 30 no different.This afternoon took the head off to see if I had put the piston in the wrong way , no arrow pointing towards the exhaust port.Top of the head thick in black oil :roll: Any ideas? When its on the stand revs all the way no problem. Slides got a few shiny spots (runs open mouthed with a tea strainer filter). Over the winter fitted new rings,changed exhaust and fitted a BGM billet head and in the last few days new BGM V.3 stator.After seeing a thread on here I also use a LML jug (haven't checked if its precise or not ,its on my "to do" list for tomorrow) Any help much appreciated
I am playing all the right notes, but not necessarily in the right order.
Mr G in NYC
registered user
Posts: 235
Joined: Fri Jan 22, 2010 7:54 pm
Main scooter: SX200
Location: NYC. LONDON
Contact:

Try running it open mouth / no filter……… also what float needle you running
200 or 300 ?

my set up was on a Rapido 225, as follows,
120 main
70 choke jet
55 pilot
X7 needle 2nd clip from top
AV266

48mm clubman
DaveTomo
registered user
Posts: 395
Joined: Thu Oct 21, 2010 7:50 pm
Main scooter: SX 200
Contact:

Cheers Mr G, running a 300 float jet, tried with and without the "tea strainer" filter, no difference. Your set up much the same as mine expect 122 main.
I am playing all the right notes, but not necessarily in the right order.
Adam_Winstone
registered user
Posts: 1693
Joined: Tue Jan 31, 2012 8:54 pm
Main scooter: Lambretta GP
Contact:

Has your float got a hole in it, making the fuel level much higher in the float bowl and causing it to run very rich?
DaveTomo
registered user
Posts: 395
Joined: Thu Oct 21, 2010 7:50 pm
Main scooter: SX 200
Contact:

Cheers Adam, just checked & unfortunately the floats OK as after you wrote that I thought yes, simple fix.Took the pot & piston off,thick black oil,checked the gearbox (filled about 6 weeks ago 0.7lts) got about 470 mils so lost approx 230 mils ,looks like the drive side seal has gone :evil:
I am playing all the right notes, but not necessarily in the right order.
Adam_Winstone
registered user
Posts: 1693
Joined: Tue Jan 31, 2012 8:54 pm
Main scooter: Lambretta GP
Contact:

Sounds like you've found the issue.
Strummer10
registered user
Posts: 360
Joined: Thu Oct 11, 2012 7:17 pm
Main scooter: Lambretta LI Special 225
Contact:

Adam got similar on a 30mm carb with breathe easy filter, when drop revs in say 3rd gear it bogs out when you put the power on.........and sometimes you have to drop a gear to clear the bogging.....might it be changing needle position do you think ?
Post Reply Previous topicNext topic
  • Information
  • Who is online

    Users browsing this forum: No registered users and 11 guests