Lambretta Flywheel Timing Marks

[mick1]

Marked TDC on casing (positive stop method) then set the flywheel to 17 Degrees. Using the the 2 window marks the stator was then lined up. A problem with the scooter then led us to fit a 2nd flywheel........lining up the flywheel at 17 degree it was noticed that the stator was about 10 - 15 degree out compared to the first flywheel.

I presume the 2nd flywheel should have been a straight forward fit with no adjustment needed on the stator ?

We decided to strobe the flywheel to check but didn't. If the window marks were incorrect what is to say the firing mark on the flywheel was ok, if it wasn't how would we know ?

So the question is......If a flywheel had no marks on it at all is it possible to set up and check the timing or if it has how do we check that is correct ?

I'm thinking the problem is establishing a true firing mark on the flywheel.......i suppose the answer isn't limited to Lambrettas but to all flywheels with firing marks.

[ducksta]

ring your mate at qmt he will sort it

[drunkmunkey6969]

Mick give me a ring on Sat and I'll explain in full, but for now in BREIF....

1) sounds like the replacement flywheel has an out of line boss
2) all Timing marks are inaccurate to some degree.....some more than others.
3) always strobe you cannot be 100% accurate unless you do
4) yes you can check timing with no marks....you make your own.

Dan

[mick1]

Hi Dan

When you say "strobe" what mark on the flywheel do you use ? yes the arrow on the flywheel is the firing mark but what if that is incorrect (ie 5 degree out) you may strobe and think you have 17 degree but in reality you would have 12 or worse 22. How can you check the flywheel firing arrow is correct.......or how do you make your own ?

[drunkmunkey6969]

It doesn't matter where the arrow is.....as long as you use it to mark TDC and Firing point BTDC and then strobe.

[mick1]

I'll phone tomorrow

[mac]

Is it the 2 notches on the flywheel that are in a different place? If so I would never rely on them to be accurate as I've seen them in different positions, easiest way to see if the arrows on the flywheel are in the same place is to align the keyway for the woodruff key's up and then you'll be able to see.

[rosscla]

'"Flywheel timing marks are for the guidance of wise men and the obedience of fools"

Douglas Bader