CHT and secondary timing

[Sonerai13]

Started out by setting the magnetron per the manual then setting the electronic trigger as described in the manual. The dot on the prop flange was as shown in the manual...started and immediately had a loud pop.....decided to set the electronic trigger 180 degrees opposite of what the book says to do, runs ok.

First of all, you can ignore the dot on the prop flange. It is of no value. The flywheel can only be installed on the crankshaft in one orientation, so timing of the primary (magnetron) ignition is set and cannot be adjusted. The top magnetron fires the top plugs of the front two cylinders, and the bottom magnetron fires the top plugs of the rear two cylinders.

If you had to rotate your trigger cap for the secondary ignition 180 degrees, that indicates that your coils are wired opposite of standard. The top secondary trigger is supposed to fire the coil for the bottom plugs of the front two cylinders, and the bottom trigger is supposed to fire the coil for the bottom plugs on the rear two cylinders. (In other words, the same orientation as the magnetrons - top for front cyls and bottom for rear cyls.) You could simply swap the trigger wires at the coils and it would switch the ignition to work as per the manual.

[Stogie6]

Thanks for the direction Joe. We thought about swapping out the wiring from left coil to right coil....but was not really sure. Even verified our wiring on the coils. Everything appeared to be by the book. Swapping makes sense and should get us closer. It was great to hear the engine start up after having it for so many months.

[jjbardell]

I assume you already checked the timing of the cam with a bore scope? If you haven't, check to be sure the can dot is properly aligned with the crank dots. I also had to go to the #2 needle like a lot of other people.

Joe knows his stuff and I'm sure he'll get you there quickly! Good luck.