Varitronic curve

[Raveydavey]

I'm trying to work out what deg BTDC my Varitronic will be at when the engine is at 6000rpm when starting at 22deg @ fast idle. The strobe shows it going up to about 15deg BTDC at what sounds like high revs, but dont have a rev counter so its just guess work. Does anyone have details of the curve showing where it retards? I'm guessing it is at set steps?

cheers

[Digger]

[Raveydavey]

Thanks Digger. I do have that already,
In that curve it shows fast idle@ 23deg which it holds to 4k rpm. Between 5 and 6 k it drops steeply (four deg) from 22 to 18 and then trails off; 6 to 7k = 2 deg; and 15 deg comes in at 8000
So is it simply a case of shifting this curve down a degree to answer my question? i.e. starting @22deg (1 deg lower), at 6k I'd be @ 17deg. If it does then it should mean 15deg comes at 7000?

[Digger]

I'm sure a grown-up will be along in a minute to answer that one.

[Raveydavey]

I'm sure a grown-up will be along in a minute to answer that one.

[Sticky]

Thanks Digger. I do have that already,
In that curve it shows fast idle@ 23deg which it holds to 4k rpm. Between 5 and 6 k it drops steeply (four deg) from 22 to 18 and then trails off; 6 to 7k = 2 deg; and 15 deg comes in at 8000
So is it simply a case of shifting this curve down a degree to answer my question? i.e. starting @22deg (1 deg lower), at 6k I'd be @ 17deg. If it does then it should mean 15deg comes at 7000?

Essentially yes. The Varitronic uses the same basic stator as a the Casatronic. There is a diagram of the curves at various stator positions at 7:54 on this video I made for Casa Lambretta.

[Raveydavey]

Perfect. Cheers Sticky.

Great vid BTW. Im sure I had more fun and games than that when I fitted mine.