High Idle Speeds
I'm curious as to how many of you guys running small gassers ( 50cc and less ) are happy with a 1400 to 1600 rpm idle settings required to keep the engine running. Personally I find this to be quite the norm with a majority of the new gasoline/ignition engines being manufactured and sold in the marketplace these days.
I have flown,rebuilt,and converted many glow and gasoline engines. All being single cylinder engines. The best engine I have converted to date is the Webra "Bully" 35cc. I convert them to Rcexl ignition and replace the original carb with a Walbro WT-540 carb. This engine will consistenty idle at a steady 1000 rpm or less without a hiccup or sputter during transition to full WOT using a 19x8 prop. I sold one of my Webra conversions here on RCU and the buyer was elated when, on the very first run, the engine idled down to 950 rpm and never quit or missed a pop.
With many modelers focusing on the peak power specs of an engine, shouldn't we also be looking at overall performance which includes the low end performance also? Especially when it comes to Scale flying? I know that many are boring holes in the sky with giant 3D planes that aren't really concerned with the idle except when they want to land.
This is my own personal observance but I find that some engines idling out at 1600 rpm is not really that good and also is a sign of poor porting design ( turbulent airflow). I have watched many pilots that have to taxi their plane off of the asphalt and on to the grass just to get them to stop rolling.
I'm not bashing one brand against another. Just wondering if any of you find the idle speeds of your gasser to be too high. In many cases the idle is set high in order to keep the engine from quitting. I understand there are many factors leading to high idle speeds such as internal mechanical resistance but I am inclined to believe that these new engines are a product of poor porting and mass marketing. Grab the money and run!
I would like to hear from any of you that has a small gasser <50cc that you are REALLY pleased with the overall performance.
Speedy