Certainly one's experience helps insure that tools will be used in an effective and non-damaging manner; however; what I wish to suggest by the term "attitude" goes well beyond these easily perceivable benefits. Or to put it another way, before a tuner employs his tools, he must first approach the machine in a selfless, open-minded manner, fully alert to receiving the many subtle indications of what it requires you to do for it so that it can perform at its best. With close observation, and using all your senses, much can be deduced pertaining to correct carburetion. Noting the "voice" through the tail pipe, the engine's response to throttle movement, the color of the carbon deposits, and even the smells of the gasses all provide important information to the savvy tuner. Once the plug color and the details conveyed by the exhaust system are considered, together with the manner of running, then the adjustments can be made to restore or establish those natural conditions that the motor needs to perform at its best.

As suggested above, carburetion influences all running characteristics because maximum power derives from optimum burn temperature and its effect on pressure exerted upon the piston. If the carburation is too rich, then that temperature is quenched, and chamber deposits accumulate, plugs foul, and mileage suffers. If the conditions are allowed to worsen then the power output falls and erratic firing often sets in. On the other hand, a lean burn condition produces its own tell-tale signs. The excess oxygen present within the chamber causes a sudden increase in heat as detonation replaces normal burn rate. The spontaneous and uncontrolled ignition results in loss of power, roughness, and noise. If allowed to continue, the crown of the piston will fail, suddenly melting away, molten metal blowing through into the crankcase. Indications of this lean condition in the short term, generally apparent to a capable tuner, are a tendency to cold-cough or spit back through the carburetor and weakened response. The engine actually answers the throttle in a delayed manner--"falling on its face" is one way to describe this fall off in surge. Further evidence is often provided by the color of the plug's electrode and porcelain: a light gray to dead white generally confirms the engine to be in a lean state of tune. More severe indications include a blistering of the ceramic, and quite possibly, metal flecks making their dreaded appearance indicating melting of the piston. The plugs' electrodes often show heavy erosion and melt off too.

In contrast, a rich condition is evidenced by a sooty black plug center, and running indications include a heavy and unpleasant odor to the exhaust, a sooty tailpipe deposit and even a visible puff of black smoke as the motor is gunned. Heavy fuel consumption goes without saying, and if extreme, then the motor will run lumpy and slower, perhaps eight stroking--a regular dropping of beats under load, actually sounding as if the choke had been left on. Because the temperature of the burning mixture never reaches the optimum, expansion pressure and the totality of burn suffers, all effecting the power produced.

Indicators of incorrect ignition advance include sluggish response when all else is correct, a sure sign of needing more spark 'lead.' On the other hand, onset of tinkle or spark knock as loads and throttle opening are increased serves as an indication of too much advance.

Do not forget that today's fuel possesses poor knock resistance, lacking tetraethyl lead in its formation, and that older hemispheric chambers are prone to spark knock at low speeds due to their poor swirl characteristics. One should be aware that a lean condition does accentuate this condition, so deal with it accordingly. As the revs rise, this transient tinkle fades due to better flame spread and can often be eliminated to a great extent by slowing the ignition advance curve characteristics through stronger automatic timing advance springs or a decrease in advancer weights, or both. Delaying the rising curve until the engine hits higher R.P.M. levels improves chamber turbulence and burn pattern, thus allowing more ignition advance, and suppressing spark knock. In turn, this state of tune permits more throttle to be used, and so more power and speed developed without motor distress.

If you approach the problem with the mindset of being able to make the motor do what you desire it to do through sheer force of your will and mechanical ability, then much of what you attempt will surely fail. For without first attuning yourself to an awareness of its needs, you will be unable to heed those signals the bike is attempting to give you. In a very real way the motor is master and a tuner only its willing and able servant. Supply its needs and it will reward you with success. Similar observations were related to me by an old friend, who besides being an absolutely brilliant machinist and fabricator, was a record holding drag bike builder for several years. His highly modified and massaged engines established record elapsed times and speeds, yet breakage was extremely rare. In his approach, Ron was always keenly observant, highly analytical, and uncompromising in his quest for perfection in every related craft and detail. Although a shy man, his absolute rapport with those motors enabled his rider to best most challengers, laying down flawless runs, time and again. While modern diagnostic equipment attempts to replace skill, a gifted tuner's work transcends mere tools and becomes a form of art. Surely most artists work from the same pallet of colors, canvas and brush, poets employ the same vocabulary, yet in no way do all their efforts result in equally rewarding and evocative results. Phil Irving , responsible for many outstanding designs, including the Vincent, once remarked to me over breakfast, "I talk to them, for if you hit them too hard with a hammer, they will pay you back!" Consider carefully the words and attitude of one of the very greatest engine designers of all time, because it begins to explain his success, and my tuning theory.