LCGB Forums

Rob Miller wrote:I know it seems hard, but I would suggest that you need to take it to someone experienced with shaft drive motors who can check it over and sort it so that you can enjoy riding a reliable Lambretta when it's finished.

Hi Rob,

Yes I am considering this. :/ would you recommend anyone in London?

It's possible that the slight movement you feel when rotating the flywheel by hand is due to other causes.

For example:-
- Increased clearance between the piston rings in their grooves in the piston, which will allow slight vertical movement of the piston in the barrel, before the rings start to move.
This clearance will increase as the engine wears.
- Excessive clearance between the small end bush and the gudgeon (piston) pin, which also increases with wear.
- Backlash between the crank bevel gear and the clutch bevel gear, due to wear or incorrect setting during assembly.

Even with a newly rebuilt engine, it's possible that very slight movement may be detectable, due to the normal clearances between these parts.

Steve J wrote:It's possible that the slight movement you feel when rotating the flywheel by hand is due to other causes.

For example:-
- Increased clearance between the piston rings in their grooves in the piston, which will allow slight vertical movement of the piston in the barrel, before the rings start to move.
This clearance will increase as the engine wears.
- Excessive clearance between the small end bush and the gudgeon (piston) pin, which also increases with wear.
- Backlash between the crank bevel gear and the clutch bevel gear, due to wear or incorrect setting during assembly.

Even with a newly rebuilt engine, it's possible that very slight movement may be detectable, due to the normal clearances between these parts.

Hi Steve,

Thank you for the info. I will have to consider all of these things and probably will have to inspect the engine better.

The tapers are worn so much that the woodruff key is too big for the small, remaining slot; in which, it really does not fit at all now. We're way past glue keys and lapping tapers. You need to replace both the crank and the flywheel.

This place seems to have the crank:

https://www.olimpiaparts.eu/it/

Myself, I would check with Howard Chambers. He is the shaft drive god and has lots of used spares to hand.

jbcollier wrote:

Yup! Definitely toast......

jbcollier wrote:This place seems to have the crank:

https://www.olimpiaparts.eu/it/

Myself, I would check with Howard Chambers. He is the shaft drive god and has lots of used spares to hand.

thanks for the link.

Would you know where is the best place to find Howard's contact?

Hi, as you are in London, give Patch@Scooter Surgery (Hammersmith) a call.He has good knowledge regarding shafters

trotsky wrote:Hi, as you are in London, give Patch@Scooter Surgery (Hammersmith) a call.He has good knowledge regarding shafters

thank you so much!

The only contact I have for Howard Chambers is a phone number: 0 2 3 8 0 5 5 0 2 7 0. Weekdays from 10.00am to 16.00pm.

jbcollier wrote:The only contact I have for Howard Chambers is a phone number: 0 2 3 8 0 5 5 0 2 7 0. Weekdays from 10.00am to 16.00pm.

Thank you for the help JB.