G109 Starter Motor

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

Stamped on, or cast into, the alloy body is the following:


E76-0.5/12S – VAR.9



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:


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


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.”






Odyssey Battery in G109


7.27 (185) x 6.67 (169) x 14.7 (6.0)

G109 General Information

G109 100 Hour Inspection

G109 Rudder Removal

G109 Tailwheel

G109 Handling Notes

Hoffman Propellors

G109 Marelli/Fiat Starter Motor

G109 Cooling modifications

G109 Toolkit

Slick 4230 Magneto

Limbach External Oil Filter

Fuel Topics

Grob 109 Scale Model

One thought on “G109 Starter Motor”

  1. Aloha from Hawaii, we have operated two motorgliders commercially,a g109b and a Samba,for island tours and insruction.The 109b has been the most successful for our operation,wish we had another!So I was very interested to see that you operate one and have lots of usefull information about it on your website.We recently top o.h.d the engine,after hundreds of hours of trouble free operation.I myself have flown it over 1000 hrs of tours and instruction and have come to appreciate the great qualities of this remarkable aircraft-Dr.Eppler got it right! Looking forward to sharing our experience (yours and ours)re operation and maintenance issues. Mahalo,Steve Lowry.

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