Plug chops

[Shipleystevep]

Ok, bit of advice please.
I know about plugs chops to check jetting etc. but what exactly do you do?
I think check at 1/4, 1/2, and full throttle - yes?
How far do you need to run to get a good check? - half mile??
Does it matter what gear you're in ?

Still learning so be gentle

[Daggs]

I'm really not sure it's possible to do a plug-chop at anything other than tickover or running in fourth at a comfortable speed for a while.
Personally I only check after a normal run around a small lap of local roads comprising about a one mile journey. I cut the ignition as I approach my drive in order to check main jet running rather than any other part of the carburation. After all this is the most important jet to get right.

[bazza3004]

Plug chops should be done at 1/4 - 1/2 - 3/4 and full as you dont run all the time at full chat / on main jet.

[Donnie]

http://www.lambretta.co.uk/downloads/carbsetup.pdf

[Shipleystevep]

Thanks chaps

[corrado]

Start by putting some masking tape on the light switch housing and some around the throttle grip. With throttle off mark the piece on the switch housing and a corresponding mark on the throttle piece, then twist throttle to wide open and mark the wide open throttle position, then mark the in between positions at 1/8, 1/4, 1/2, 3/4, 7/8 ths positions. Then find a nice by-pass with lay-byes. Ride at various fixed throttle settings constantly for 1/2 mile or so. What you're trying to do is get an image of the plug at a specific point in time. You have to switch off ignition, pull in clutch immediately and coast to a halt, I try and time it so I coast into a lay-bye out of harms way when removing the plug. One thing I would recommend is to get a MB plug socket and a flexible head ratchet spanner, makes the job 10 times easier and saves burnt figures on hot plugs.
http://www.lambrettaspares.com/spares/t ... p0267.html