ORIGINAL: abrom1
ive gotten the alligator tours airboat and was wondering with the glow plug supplied it seems to be difficult to get to a leaner condition, have the lsn at a little less than a turn and the high speed at 2 turns compared to the factory set at 2 1/2 turn on the high needle . motor still seems fat and the glow plug has never tinted yet . i do live at about sea level . is it a glow plug supplied for safe tuning and not for optimum performance and throttle response for safe practice? has anyone gotten this boat also with the 27re?
That engine is basically an RC car engine with an airplane prop on it. Tuning those kinds of engines is a little trickier, but not hard to do. First off, did you break the engine in properly? If not, do so first as the engine will needle better once its got some runtime on it. 2-3 tanks of fuel at WOT
slightly rich will do the trick. As for the glow plug, it will not control how rich or lean you tune the engine to a point. If you're using the proper airplane fuel with 5-10% nitro and 20% oil, it should run well enough. Super Tigre glow plugs are not known to work real well, so getting some extras of another brand isn't a bad idea. Besides, Break-in is tough on glow plugs and oftentimes needs replacement after break-in is done. McCoy MC59, Enya #3, OS A3 plugs all work well and are hot heat range. Super Tigre engines tend to like hotter plugs. Once you have the proper fuel, glow plugs, and the engine is broke in sufficiently, set the needles on the carb like this:
Ignore how many turns the needles are set, this number is irrelevant. Open the main needle (high speed) 1/2 turn from wherever it is currently, and start the engine. It will be rich. Run to WOT and let run for 30sec-1min to warm up. Now lean the main needle down until its "just" running in a clean two-cycle smooth run. Pinch the fuel line to the carb
momentarilyabout 1-1.5" from the carb. The RPM should go up enough to hear. If it goes up a lot, turn the main needle in 1/16th of a turn until the rpm only goes up a little bit when you pinch the line. If you pinch the line and the rpm doesnt change or cuts out, its too lean and open the main needle 1/8th turn and try again. The idea is the engine runs slightly rich at a full tank and about perfect at half tank. The idle needle gets set for a good transition from idle to WOT. Most Supertigre ABC engines like to idle 2,700rpm-3,000rpm. Too low or too high idle rpm will be harder to get the idle needle set. Its always better to start off rich and lean it off. I lean my idle mixture down until a quick full throttle jab of the throttle makes the engine cut out slightly, then richen about 1/16th turn. Richen the idle needle until you get a quick throttle response from idle to WOT. If it loads up at idle and runs rough and smokey when going from idle to WOT, its too rich. Cutting out and/or quitting is too lean.
This may seem like a lot, but its what I would tell anyone thats never used one of these engines before. If you've ran RC Cars in the past, you have a jump start on tuning.. Engines with air props are very very easy to set, if you do it in the right order. Always tune the high speed needle first, with the idle mixture second.
Hope this helps you.