How the Onan Engine Starter Arm works on the Walker

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When the starter rope handle is pulled in the cab the starting lever is raised and the roller on the end of the arm tightens the V belt between the starter motor and the Onan engine. At the same time the the switch on the end of the lever closes energizing the solenoid and applying power to the starter motor.


The V belt between the starter motor and the Onan engine is held from flipping off the pulley by the U shaped bracket. The spring holds the starting lever out of the way and also keeps the rope tight.


The starter arm is missing the other spacer and locknut at the switch end of the arm. I machined the spacers to align the starter lever with the belt.


The roller is a 1 1/4 inch roller bearing cam follower with 1/2 inch bolt. Also there is a chain link welded to the bolt and nut therefore I can not remove the roller for replacement. At this point the roller is a little rough but works fine.

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Starting lever is 9 1/2" long X 1" wide X 1/4 " thick. The hole for the roler is 1/2". The 1/4" hole for the spring is 5 3/4" from the roler end of the arm.


The tab to mount the switch is 1" wide X 1 1/4 long welded at about 45°. I added a piece of metal bent at 90° with a couple of holes for a Ty to hold the wires. NOTICE the bushing welded at the pivot point ! !


The spring is 3 3/4" long and 1/2" dia. almost any spring tension will work, it only needs enough tension to keep the rope tight. I added spacers on the bolts to keep the spring in alightment.


Another photo of the switch, almost any momentary normally open switch will work, the only current through this switch is enough to energize the starter solenoid.

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The adjustment bolt under the switch is used to set the switch to close when the starter belt is tight enough to turn the engine over without slipping.

This is a very simple set up to start the Onan, I would suspect that in 1964 a Onan engine of this size wouldn't be available with a starter motor and the engine would be started with a pull rope wound around a pulley.

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