Since your engine is a true ABC-type design (high silicon content aluminum alloy piston running inside a hard chromeplated
brass cylinder-sleeve), it should be brought-up to temperature as quickly as possible, allowing the sleeve to expand
enough to achieve optimal fit; otherwise, the piston will scrub the sleeve excessively, causing premature wear, loss of
compression, and diminished performance.
4. Here’s the tricky part: to the best of your ability, immediately begin dialing-in the high speed needle valve for maximum rpm
performance during the first tank of fuel. During this period, cycle the engine between WOT (full RPM) and idle in 5 to 10
second intervals, by making high speed passes, on the type surface you prefer to operate on – this will keep the piston and
cylinder-sleeve hot enough while the operator tweaks the needle during quick pit stops. A helper is very handy for this critical
operation! If the engine quits before the idle is set, that’s okay – just allow the engine to cool off – heat cycling is part of the
break-in process. Ideally, get the needle valves set for maximum performance and a reliable idle as quickly as possible
(see the Needle Settings section of your manual for more detailed information). If performed correctly, the engine should be
running near normal operating temperatures for the entire break-in process. Depending on the operating surface, outdoor
temperature, etc., your break-in temperature will range between 220º and 260º F. Following the above procedures, run the
engine for a complete tank of fuel – then shut it down. Allow the engine cool down COMPLETELY before re-starting.
5. Continue this process for about 4 tanks of fuel; this heat-cycles all the metal parts inside your engine.
IMPORTANT: Do not let the engine sit and idle for its break-in. The piston and cylinder-sleeve will not get hot enough to expand
properly, and the critical pinch-fit will disappear before you know it. In fact, you should be more concerned about running an engine too
cool, rather than too hot!
