...but what was causing it to darken?

Yes, inquiring minds want to know. You can run an engine with the tune way far off but it shouldn't be flowing dark mater out the muffler, oil yes, dark mater no. What did they find??

This is the infamous "Grey Goo" problem with new Evolution engines that is so often written about.

A new Evolution engine will tend to wear in, dropping metalic particulates into the exhaust & muffler ( and thereby the fuel tank! ).

He used Castor containing Omega fuel, so the overall effect when coupled with his rich mixture is the "coke" appearing fuel in the tank.

The wear stops after about 1-2 gallons have been run through the engine.

This same grey goo, will also clog up the muffler nipple, so it pays to clear it often until the engine is fully broken in.

BTW: I prefer to run Cool Power instead after the first two runs, so I can see how broken in the engine is...

This is another reason that it pays to have a fuel filter between your tank and carb. Filtering the fuel from the container does not get rid of these metal particulates, so an in-line filter is preferable in spite of claims from others.

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