83 125 jetting 84 125 timing?

[Mike Lenz]

I am building a 1980 125 KTM for mx.  I ported the 80 cylinder to kind of match the 83 watercooled cylinder (opened up the exhaust and intake more).  I am also using a internal Motoplat that is marked from a 84 125 KTM that has a cdi box.  What I dont have is the jetting for the 83 with the 34mm Bing(which I will be using)and the timing that was used with the 84 or later 125's with the CDI Motoplat.  The 80 125 timing is speced at .9mm. Newer KTM's I see are 1.4mm.  The CDI makes the timing farther before TDC as the revs go up, correct? Is that advancing or retarding, I forget?? Anybody got anything?

[ALB]

Mike,

The 1984+ 125 came with Delorto carbs.
I don't have any info on the 1983's.
The internal fly Motoplats with the CDI box came on the 1987 125s (engine type 502). Prior years came with internal Motoplat without the CDI Box.
Engine timing for the Motoplat with CDI box =
    MX - 2.5mm (22.3 degree)
    GS - 1.4 to 1.5mm (16.7 to 17.3 degree)

Alan Buehner

[Mike Lenz]

Thanks Alan, that helps!