Technical Tips
Frequently asked Question:
What's a dyno ??
A dyno is a machine in which the bike is strapped on and power is measured.It can also be used to break in an engine.
NOTE: If you use a dyno with a brake, it's critical during break - in that you allow the engine to decelerate fully on it's own. (Don't use the dyno brake.)The engine vacuum created during closed throttle deceleration sucks the excess oil and metal off the cylinder walls.
The point of this is to remove the very small (micro) particles of ring and cylinder material which are part of the normal wear during this process. During deceleration, the particles suspended in the oil blow out the exhaust, rather than accumulating in the ring grooves between
the piston and rings. This keeps the rings from wearing too much.
You'll notice that at first the engine "smokes" on decel, this is normal, as the rings haven't sealed yet. When you're doing it right, you'll notice that the smoke goes awayafter about 7-8 runs.
Important Note:
Many readers have e-mailed to ask about the cool down, and if it
means "heat cycling" the engine.
No, the above "cool down" instructions only apply if you are using a dyno machine to break in your engine. The reason for cool down on a dyno has nothing to do with
"Heat Cycles" !!!
Cool Down on a dyno is important since the cooling fans used at most dyno facilities are too small to equal the amount of air coming into the radiator at actual riding speeds. On a dyno, the water temperature will become high enough to cause it to boil out of the radiator after
about 4 dyno runs. This will happen to a brand new engine just as it will
happen to a very old engine.
(Always allow the engine to cool down after 3 runs whenever you use a dyno.)
If you're breaking your engine in on the street or racetrack, thehigh speed incoming air will keep the engine temperature in the normal range.
(In other words, you don't have to stop by the side of the road to let your bike cool down.)
What about "heat cycling" the engine ??
There is no need to "heat cycle" a new engine. The term "heat cycle" comes from the idea that the new engine components are being "heat treated" as the engine is run. Heat treating the metal parts is a very different process, and it's already done at the factory before the engines are assembled. The temperatures required for heat treating are much higher than an engine will ever reach during operation.
The idea of breaking the engine in using "heat cycles" is a myth that came from the misunderstanding of the concept of "heat treating".
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