Adjusting ignition timing
Unless otherwise stated, the values for ignition timing adjustment apply to 40 mm stroke and are measured before TDC.
The values give you an overview of the ideal value for the respective engine. However, do not forget that ignition timing, exhaust, compression ratio, etc. are interrelated and can influence this ideal value.
In general, the ignition timing should be changed or readjusted whenever the displacement, stroke or connecting rod length is changed.
Example for Malossi setup with 44 mm stroke:
Basic setup x long stroke ÷ original stroke = setup with long stroke
2.25 x 44 ÷ 40 = 2.475mm
PVL:
PVL Analog
1.0 to 1.4mm
PVL KRD digital
5.0 to 5.8mm
PVL Stage 6 :
Stroke 39.2-39.3mm:
Connecting rod 80mm: 3.20mm
Connecting rod 85mm: 3.17mm
Connecting rod 90mm: 3.13mm
Stroke 43mm:
Connecting rod 80mm: 3.57mm
Connecting rod 85mm: 3.53mm
Connecting rod 90mm: 3.49mm
Stroke 44mm:
Connecting rod 80mm: 3.68mm
Connecting rod 85mm: 3.63mm
Connecting rod 90mm: 3.59mm
Stroke 45mm:
Connecting rod 80mm: 3.78mm
Connecting rod 85mm: 3.73mm
Connecting rod 90mm: 3.69mm
Pvl Bidalot factory :
Stroke 39.2-40mm:
5.8 to 6.2mm
Stroke 42mm:
6.2 to 6.6mm
Stroke 43mm:
6.4 to 6.8mm
Stroke 44mm:
6.6 to 7.0mm
Stroke 44.9mm:
6.8 to 7.2mm
PVL digital bidalot and conti (500 104 or 105 500 54) :
5.6 to 6.0mm
PVL digital external:
0.0mm
POLINI:
Induction frontal: 1.4mm
SELETTRA:
Malossi:
Malossi MHR scooter: 2.25mm
Malossi MHR 50cc motorbikes: 3.3mm
Italkit:
Itakit analog: 1.2 to 1.7mm
Italkit digital Curva: 0.0mm (align rotor/stator to TDC of piston)
MVT:
Digital Direct
DDs with RJ34-3/4/5 housing have a 1.5mm gap for the 40mm stroke (original) and 1.35mm for the 44/45mm stroke.
DDs with RJ34-6/7/8 housing are set at 0.4mm for 40mm stroke (original) and 0.35mm for 44/45mm stroke.
Millenium
MVT Millenium: woodruff key in position A
MVT Millenium + Digimax: woodruff key in position D
Premium
MVT Premium: 0mm (TDC)
MVT Premium + Digimax: 1.3mm
MVT gp
(older model, no longer sold) digital outer rotor: 4.3mm
CONTI:
CRX Neutrino: 6.0 to 7.0mm
HPI:
Digital: 3.7mm
Doppler:
Analog: 1.5mm
Digital: 3.2mm