Rotax Wizard wrote:
Hello Jesse
The factory setting is always 1.5 turns. If you have to deviate that suggests something else is wrong.
Cheers
my teeth always grind a bit when I see this information repeated without further explanation.
In my experinece thus far with my AFR system installed on at least 5x 912's in my region alone the 1.5 turns out from fully seated results in engines running in the 14.9 to 15.2 to 1 ration from an AFR standpoint - and this was measured with a computer system, not assumptions or by watching EGT's. In two instances, the carbs were fresh overhaul delivered back to the aircraft owner directly from Leading Edge and the carbs read 15:1 at idle.
The callouts within the manual are a STARTING POINT. you have to consider that while engine components are being produced, the tooling wears and the material proeprties are not identical between batches of raw material. With these slight variations in the tooling as well as the base material, variation is EXTREMELY likely.
Anyone who has spent any time tuning engines in cars, motorcycles, boats, even a single cylinder go-kart knows that while you are provided some numbers in terms of a starting point when your going through the manuals, tuning is ALWAYS required. If you want to know how your engine is behaving while running throughout the entier RPM range, I strongly suggest borrowing, renting, or buying an AFR meter and tuning the engine right. Ive mentioned it here as well as a few other sites - when I started tuning the engine, I ended up gaining 900 RPM as a result of the attention placed into just the carb jetting. Its worth doing right. If youd like to see the process and the video proof of these gains, they are posted on Youtube.
