Quote from the Salt Racer Thread Elsewhere

[Vince]

That's neat onboard footage Gunerdo.

It's a common mistake for newbies to run a street tune, or what worked on the dyno at home, but you actually need a nice fat rich mixture for the top end to keep it cooler eh, otherwise pistons just melt. It's a juggle between being too rich to work properly and just rich enough not to burn pistons at extended full load revs. Too much fuel will also ruin an engine in short order too.

 

[MotoJouni]

That's neat onboard footage Gunerdo.

It's a common mistake for newbies to run a street tune, or what worked on the dyno at home, but you actually need a nice fat rich mixture for the top end to keep it cooler eh, otherwise pistons just melt. It's a juggle between being too rich to work properly and just rich enough not to burn pistons at extended full load revs. Too much fuel will also ruin an engine in short order too.

Personally I have doubts considering many of those eddy current or inertia only dynamometers widely used today. They are widely used because these principles give opportunity to make also cheaper models. Adjusting mixtures on accelerating situation only may lead to leaner mixture settings. I think the engine must be reved at constant (or at least very near constant) RPM with wide open throttle. The load must be adjustable to reach these points with different revs.

Someone once tried to sell me "dyno" which was a some kind of meter that monitors how rapidly the revs go up just against the inertia of the engine itself while gear on neutral position. I told the seller to wipe his butt with his machine. This kind of system will lead to very lean mixtures.

 

[Cosi]

It has a lot to do with air density, something I'm coming to terms with racing a 2 banger