A/F Question

[bigpsi94]

Say I run 13.0 at idle and if I were to lean it out to 15.0 what would I do to the timing and why? What about when the weather gets warmer or colder how is the timing affected?

 

[bruce]

Originally posted by bigpsi94
Say I run 13.0 at idle and if I were to lean it out to 15.0 what would I do to the timing and why? What about when the weather gets warmer or colder how is the timing affected?

To run leaner you need to advance the timing, slightly. Leaner mixtures are slower to burn.

As temps rise, up until a point, you add timing, to recover the lose of cylinder pressure due to the less Dense air.

Real short answers, for involved answers.

Just as a freebie, when air density increases you have to slightly lean the engine, since the backpressure increases more then enough to negate the density increase.