[Jpm757]

Just "unpickled" my new Lycoming O-360 purchased through Van's. One would assume a new engine that has been test run for 2 hours would have the correct ignition timing when delivered. Magneto timing was way off. I had the same issue with my YIO-360 in my -7.
All I can figure is that these engines are run with "test cell" mags afterwards they are replaced with the customers ignition preference, but apparently just roughly timed. My Slick mags even had factory torque seal on the nuts.
DON'T ASSUME YOUR IGNITION SYSTEM IS PROPERLY TIMED FROM THE FACTORY.

 

[Canadian_JOY]

Just "unpickled" my new Lycoming O-360 purchased through Van's. One would assume a new engine that has been test run for 2 hours would have the correct ignition timing when delivered. Magneto timing was way off. I had the same issue with my YIO-360 in my -7.
All I can figure is that these engines are run with "test cell" mags afterwards they are replaced with the customers ignition preference, but apparently just roughly timed. My Slick mags even had factory torque seal on the nuts.
DON'T ASSUME YOUR IGNITION SYSTEM IS PROPERLY TIMED FROM THE FACTORY.

This truly is the case. I've also seen the same from engine overhaulers - they don't want to waste time troubleshooting a customer's ignition system or trying to adapt their test cell wiring to that customer-specific ignition. They install their own mags, wires and plugs, then when done the run-in session the customer's ignition is bolted on prior to the engine being bagged for shipment. That installation is literally a bolt-on process - they don't waste the time associated with timing the ignition exactly.