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Old 04-12-2009, 03:44 PM
Bob Pastorello
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Join Date: Feb 2002
Location: El Reno, OK
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Default RE: Newbie to Gas General Information

Already asked....we'll wait and see.

28. RPM readings. Nearly meaningless for one user to compare to another user. Even if using the same prop. Carbs are very sensitive and being off the sweet spot by 1/16th turn on the H needle can make a big difference in tach readings. Plus, most tachs are semi accurate, part of the time, and light/angle sensitive all of the time. Unless you know me, and how I I tune, my altitude, air density, oil mix ratio, type of oil, and heat peak rpm is of no consequence to you except for "ball park", and it's a helluva big park. Most 50cc gassers and above should be somewhere around 7000 with the "stated" prop from the manufacturer. Larger displacement, lower peak rpm. That's how it goes.

29. Freqently check your ignition battery voltage. Under load, if possible. An ignition battery that is losing it's guts will create bizarre unreliable and misfiring engines.

30. If your engine was fine yesterday, and today it's NFG, then *something* changed. Find what changed, and fix it. Don't jump to conclusions and speculate. Work through the systems. Start at the tank, work through the plumbing. Start at the battery, work through to the plug, start at the servo, work through to the butterfly. Only a VERY few, and "special" engines are actually sold with Gremlins built into them. Usually they have already been owned by someone who couldn't find and kill the gremlin, so you got it. Think of a finicky motor as a PC virus....there is a just have to find it.
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