Why two TC1 marks on the flywheel?

[David_Nelson]

Hi All,

Yesterday evening I was ready to phase the LSE-II ignition. Went through the usual steps (ensured all ignition switches were 'OFF', removed top plugs, removed plugs wires from LSE coils, removed bottom plug wires, and rotated the engine until TDC #1 is reached using the 'thumb in the plug hole' method).

With all that done, I glance at the front of the fly-wheel and the TC1 mark is at the 5 o'clock position. What the heck is going on here? I repeat the TDC exercise a couple more times and I get the same results. Now, I'm pretty sure I put the fly wheel on correctly as it only goes on one way.

By chance, I look at the back of the fly wheel and "viola!", the TC1 mark is lined up with the case halves.

Why are there two TC1 marks stamped on the fly wheel in very different positions? Engine is a TMX-IO-360-M1B.

Thanks,

[scard]

The front mark is meant to line up with the little hole in the starter case. It works.

[noelf]

...there are two TDC marks. They are provided for the convenience of the person working on the engine, and if some "stuff" is in the way of one set of marks, hopefully the other set is viewable.

[David_Nelson]

Thanks guys.