He inspected the needle valve with much care, and had Foster on the front seat trying to start her afterwards.

He looked for short circuit.

He changed the carburetor adjustment, and Foster got a weary chug-chug that ceased almost as soon as it had begun.
He looked all the spark plugs over, he went after the vacuum feed and found that working perfectly.

He stood back, finally, with his hands on his hips, and stared at the engine and shook his head slowly twice.
Foster, in the driver's seat, swore and tried again to start it.

"Maybe if you cranked it," he suggested tentatively.
"What for?
The starter turns her over all right.