Thread: Jerky Runner
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Old 10-12-2019, 08:20 AM   #36
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Join Date: Jun 2010
Location: San Antonio, Texas
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Default Re: Jerky Runner

The two most common problems that can happen after a car sets for a time is fuel deterioration and sticking valves.

Fuel doesn't last very long unless it is a higher quality formula like 93 octane premium. Avgas last a lot longer but it's overkill on a model A and it's not legal to run it in cars. Draining the fuel is a PITA but sometimes it's the only way to insure a clean fuel system.

MMO and running the engine regularly are the best way to prevent sticking valves. I wouldn't use any more MMO than is necessary. This isn't a 2-stroke engine and they generally get enough blow by to keep the piston rings lubed up. They don't run well on oil and solvent alone. It doesn't take all that much MMO to do the intended job.

We run the aircraft engines every 2-weeks if they are in flyable storage. This is considered the minimum interval for safe flight. Even 2 months is too long.
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