Scooterotica

Motor's running after complete build with almost all new components.

It's my first Lambretta, so forgive me if I ask anything stupid.

I'm trying to strobe my ignition (varitronic) and it seems to be 24 degrees at fast tickover. As I rev it (nervously) the timing appears to be static until around 4000 rpm (engine speed judged by ear). Then the mark disappears round to 180 degrees out.

I assume that this is because there are 2 sparks per revolution, but how do I strobe it correctly? This seems especially difficult as I don't have a rev counter.

it's a GT186 with Ancillotti clubman, so not particularly revy motor. I'm guessing it will max out at around 7500rpm.

Advice please?

snapon

Surely there's another option. I'm just a fella who farts around with stuff at home for something to do.

I don't want to spend snapon money for a tool that I'll use 3 times in my life.

I've had no problem strobing my varitronic with a cheap timing light. Have you made any timing marks on the flange? I put some marks on at 17,20,23 or something like that and set mine from there. Can't remember what though and have it written down somewhere. It may just be you are missing the first spark so to speak.

vespanic wrote:I've had no problem strobing my varitronic with a cheap timing light.

how many rpm did you strobe at?

vespanic wrote:I've had no problem strobing my varitronic with a cheap timing light. Have you made any timing marks on the flange? I put some marks on at 17,20,23 or something like that and set mine from there. Can't remember what though and have it written down somewhere. It may just be you are missing the first spark so to speak.

i've done pretty much the same with marks at TDC, 17, 21 and 24.

At high tickover it's at 24 then as I increase revs it suddenly disappears 180 degrees around the flywheel. This must be from the 2nd spark from the varitronic.

So it does work ok at tickover, but what I really want to know is that it retards as I go beyond 4000rpm and see that it's more like 17 degrees at 7000rpm, although I'm a little scared to go that high with an engine not run in yet.

What make of timing light did you use?

I have had this on varitronic before and although i haven't tried it, i understand triggering the timing light (dont hold the trigger in but keep pressing the trigger in quick bursts) helps.
Apparently some timing lights do this with varitronic ignitions.

I think I bought the timing light from Halfords years ago. I'm not sure of the revs because my tachometer doesn't work with the varitronic but I keep the revs at just over tickover which is about 2000 revs. I would have thought that if you have 24 at high tickover then the unit is working well and I would agree that the 180 is the 2nd spark.