Scooterotica

got a 186 that is suffering from clutch drag and cant seem to be able to set it up,it is a standard surflex 4 plate with uprated springs but when together there just isnt enough travel on the plunger to fully disengage the plates,well i say that but when it is cold i pull the clutch in and it goes in gear but within seconds the clutch starts to bite and bites more and more untill it stalls,have tried the usual different springs ,thinner steels,bent the tabs on the bottom cork,dressed the lever for more leverage,even shortened the clutch arm for more leverage but all still the same,any more suggestions before i fetch the hammer?

Check for contact wear between the pressure plate and the spider. Also check the pressure plate runs concentric with the spider and layshaft (if it is the type with the plunger). Check that the top of the pressure plate where the springs locate is not deformed or damaged (this is common if you use springs that are too strong for the metal pressing).

If every thing passes muster above throw the springs away and start with springs that you know are from the same batch. If one of the springs is weaker than the others then the clutch will not release evenly or concentricly and drag is usually the outcome.

The pressed metal parts that make the spider and pressure plate are the achilles heal in the Lambretta clutch.

Is the chaincase an LI type or GP. If its LI and your gearbox isn't drilled for a pressure plate with a plunger/locator the clutch will always have a tendency to disengage on the p155.
In the short term you may have to assemble the clutch with more clearance than usual to allow for it. You can get 1mm thick steels and 2mm top plates now so you should be able to achieve this. This will make the springs less effective though so not really a long term fix.
If you have got this set up then think about changing the chaincase cover for a GP one. This will at least allow the clutch to disengage evenly

...try a thinner top plate...thinner steels...or try a second hand cork plate in.....

Buy an AF Rayspeed 6 plate clutch. No slip or drag

update:tried thinner top plate and steels =same
tried 3 sets of "uprated springs" from big name dealers=same
new pressure plate =a bit better
cheap springs(all the same length unlike the others)=sorted
thanks for the replies