Scooterotica

Came in the kit from as they say a reputable dealer. If its Jap I would rather trust it over some others. Anyway its been on for 3 years at least.

Im trying to get my head round the problems some have had with the height of the pickup on the BGM.
Do they have to raise the pickup or lower it?
So again Gurus How does the pickup get its firing point?

One thing I have noticed is the flywheel does not go into the mag housing flange as deep as my other scooter. Im looking at removing the woodruff key today and lapping the boss onto the shaft. If it goes on further without the key that may be holding the flywheel further out away from the pickup. Somewhere in this sorry tale I sheared the key checking the timing not fully tight. I fitted a new key and thought nothing of it.

Monty wrote:.....So again Gurus How does the pickup get its firing point?............Im looking at removing the woodruff key today and lapping the boss onto the shaft. If it goes on further without the key that may be holding the flywheel further out away from the pickup. Somewhere in this sorry tale I sheared the key checking the timing not fully tight. I fitted a new key and thought nothing of it.

If you look at the magnets on the flywheel you will see that 2 of them overlap each other. That is the spot that causes the spark to trigger.

If your woodruff key is preventing the flywheel from engaging the taper then it is going to shear again very quickly What state is the taper surface like after the previous key failure? Did the wandering timing issue start before or after the woodruff key shearing?

Thanks for your reply Coaster.
OK been down the shed again. I had measured the distance between the stator at TDC and a point on the mag flange. Then removed the Flywheel and woodruff key and replaced it without the key and measured again. The flywheel does not sit any lower than with the keyway fitted. It was one of those in bed thoughts that if it was too high it would stop the flywheel going down the taper. The old key simply sheared leaving a part in the crank and a bit in the slot. It was not been ridden at the time so no damage to the crank or the flywheel.
I have lapped the two surfaces and cleaned a few whispers of possible iron filings off the flywheel. around the two fingers. I have also measured the BGM pickup height against the other 2 stators and they look the same. With the BGM and original CDI it revs spot on 17 and drops back to 25 is on tickover. Who needs an auto advance and retard? I just don't trust it to be consistent.
The problem with mail order is I'm now waiting for the postman and the BGM CDI
I also have a flywheel nut that is beginning to resemble Itwillrunproperly. Its been on and off so many times

Blob of Blue Tack on a wooden coffee stirrer is best method of removing swarf/filings off the magnets

Got the new bgm CDi, new plug cap, new ht lead, new plug, scoot runs fine with keytronic retard device on, change flywheel for the new "missing link" bgm sooper dooper flywheel and it's all over the place !!! Any one else had issues?????

Just a quick update.
My mail order CDI went down the route of bring returned to the post office and as they open at the crack of dawn and close at 12am, and I have been buzzing round Ireland, this week, its taken till today to get my hands on it. Fitted and at last I have stable timing.
Then decision made to give the M Tech another go. Maybe I was a bit hasty and it was £80.
SO my timing is wandering again but this time with a bit of logic behind it. No spit back either so result
Thanks again for all the help.
Monty

I am having the same problem timing all over the place bgm flywheel stator and cdi put old af flywheel on and ok just waiting for the shops involved getting back to me

Give this ago http://www.lambrettaspares.com/spares/s ... u0848.html

Maybe try changing the flywheel........could be a crack or loose magnets.

I believe flywheels have a gap in them, on the ignition side they "charge up" the stator/pick-up then when the gap goes over the pick up it does not charge allowing all the energy to be released, to fire the CDI..............but I may be wrong

Poor new parts are a consistent problem out there. I tend to have little problems with SIL parts over others ....strangely enough ??