G109 Starter Motor

The G109 starter motor is a Bendix type as fitted to some Fiats

Stamped on, or cast into, the alloy body is the following:
Fiat
E76-0.5/12S - VAR.9
4112049
S
The S is for "Sinistro" indicating counter-clockwise rotation. The pinion gear has 9 teeth.
A Bosch unit from either an air-cooled BMW motorcycle or a Moto-Guzzi may well fit - count the number of teeth on the pinion gear, and note the direction of rotation. Aircooled BMWs between 1970 and @1998 have either 8 or 9 teeth on the pinion gear. If one of these fits, then an alternative will be the French Valeo unit from later model BMWs including possibly the R259 oilcooled twins. The Valeo is much lighter, but not as reliable as the Bosch.

Early Bosch startermotor of the same type:
http://www.dropbears.com/m/moto_guzzi/images/v7-850/tav51.htm

The diagram below illustrates a unit similar to that fitted to many G109 motorgliders.

G109 Starter Motor

If the starter motor turns the propellor slowly, and yet the battery appears to have both good charge and cold-start performance, new brushes may be the solution.

Moto Guzzi starter motor Valeo replacement:
"Just transplanted a Holden Barina motor onto my Cali3. The motor came from the Spanish built car with an Opel engine."
http://www.mypage.tsn.cc/rdd/TT/contents/ELEC/starter.html

G109_Starter_Motor

Battery

Odyssey Battery in G109
PC680MJ
7.27 (185) x 6.67 (169) x 14.7 (6.0)