Modern Vespa

Hi

Bought a 68 super and been doing up a while..
Just bought 12v conversion and all fitted..
Went to time it up and made the ref marks for tdc and 18 degrees..
Threw the strobe on expecting to see it somewhere in the ball park area BUT it is miles out..
TDC is around 11 o'clock and it's strobing around the 4 to 5 o'clock mark..

How can it be that far off!! Thought I'd put the stator on wrong but it's where it should be.. Any ideas as to what I've done wrong or how to remedy would be really appreciated
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Which 12v kit did you install?

I'm going with a Bajaj. I recall mine having those same timing issues before I gave up and went back to points for a while.

Some of these things are not like the others...

Maybe wrong technique to situate TDC and 18 before TDC ? That happened to me…

I can't speak for the kit you've installed, but a someone who has built ignition systems from scratch (decades ago), I can vouch for the position of the pickup to be crucial (physical variable). The other crucial variable is delay (programming variable). Some ignitions with a variable ignition curve throw a spark on the next revolution of the engine, depending on the angular offset between the TDC and pickup (also known as pickup home position).

I'm guessing new pickup location is different, or ignition being triggered at a different angular position due to pickup home offset.

Can you share a link to what you've installed?

Hi..
Appreciate all the replies..

I've bought the whole kit from a decent scooter shop and not just guessed at bits myself..

Here's a list of parts I got..
It's the blue ducati cdi for a PXE
Flywheel is BAGLA for a PX
New 12v wiring harness fitted..
RMS rectifier
5 wire stator for a PX..

Today I extended the 3 slots for the stator approx 15mm each and refitted which has bumped the timing mark closer but I reckon it's still nigh on 90 degrees out..
Sparking like a champ..

Oh and I checked TDC again and came up exactly the same.. Even just checked with prodding top of piston and turning flywheel.. Seems to be pretty spot on TDC..

This is a long shot.... but I seem to remember some flywheels having 2 keyways cut to line up on the crank. That or your flywheel was assembled a couple of rivets off.

I'd never heard of Bagla flywheels, so I tried googling, and neither has Google.

And who made the stator?

Which leads me to: How reputable is this reputable scooter shop of yours, really?

After all, Scooterworks here in the states used to sell (maybe still do?) that garbage Bajaj electronic ignition kit that probably had at least a 50% DOA rate, then just tell everyone who complained that it must be user/installer error.

First, I can't see a make on the stator..
Seems to produce the spark really well but just not when I want it..

I've bought loads of stuff from this scooter shop and so far everything has been great..
I'll have a word with the very knowledgeable salesman and see what he says..

I think I'll have a fiddle with the flywheel and move it a couple of notches to see if that helps..

Once again I really appreciate replies and ideas.. Cheers

After moving the key ways a couple of spots over I've pretty much been able to get the timing close.. Turns out the central boss that was retrofitted to the flywheel to make it fit to my crankshaft for the 12v conversion was not correctly fitted.. Hopefully I should be able to get it timed up properly now..

Thanks for adding comments and ideas..

Any chance you can post up some pictures of what we've been discussing here?

I'm curious to see what you've got for future reference.

Following on from Jedihunter's comment, a PK flywheel loos the same and will fit but has the keyway in a different location to the PX.

I'll get some pics up from when I picked it up as a forgotten shed ornament through to today after it's been stripped and resprayed etc.. [/img]