OS 70 sv-h Breakin
04-09-2003, 05:44 PM
#2
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OS 70 sv-h Breakin
We really don't have an RPM recommendation, but you can use something like a 12 x 6 prop initially. Run the engine at full throttle just about as rich as you can and still keep it running or keep the needle valve from falling out. Do this for about 10 minutes or so. Kill the engine and let it cool down. Retart the engine and gradually lean it a bit. Stop it every 3-5 minutes and let it cool down.
After a total of about 20-25 minutes or running time, you should be running in a two-cycle mode. Continue the process over the next 20-25 minutes of running time until you are just rich of peak RPM. Now you can work on the idle mixture.
This will give you needle settings close to what will be in the heli. When you put the engine back in the heli, richen the high-speed needle a bit before starting so you won't get a lean run right off the bat. Work with the engine to get a good setting in the heli.
After a total of about 20-25 minutes or running time, you should be running in a two-cycle mode. Continue the process over the next 20-25 minutes of running time until you are just rich of peak RPM. Now you can work on the idle mixture.
This will give you needle settings close to what will be in the heli. When you put the engine back in the heli, richen the high-speed needle a bit before starting so you won't get a lean run right off the bat. Work with the engine to get a good setting in the heli.
