My Speedo worm screw isnt working very well. (Lambretta GP)

[JasonPlattsEngineer]

I have a problem with my Speedo on my Lambretta GP125 can any one give me any fault finding tips?
I have replace the worm screw which is plastic and the crown worm screw from the hub which is metal, yet my worm screw has all ready started to scar. I have only spun the wheet to see it turn and then taken it out to inspect it, to find that it is starting to look like the one I replaced. Am I doing something wrong?

Thanks people

[rog60]

I believe that you should replace both items with either all plastic or all metal which is what I have. Needle is steady at all speeds (but not necessarily correct )

[minotaur]

get a digital one off mb on order and save yourself a lot of hassle...

sorry to sound defeatist but with both the speedos and drives an accurate digi one will work out cheaper and a lot less hassle in the long run...

[JasonPlattsEngineer]

I believe that you should replace both items with either all plastic or all metal which is what I have. Needle is steady at all speeds (but not necessarily correct )

Thanks for the advice I will try this idea out I think. Tarr bud

[JasonPlattsEngineer]

get a digital one off mb on order and save yourself a lot of hassle...

sorry to sound defeatist but with both the speedos and drives an accurate digi one will work out cheaper and a lot less hassle in the long run...

I will speak to Ian at MB and price one up if the other Idea doesnt make any difference. Cheers bud.