26 Gas needle setting right?
05-23-2006, 01:06 PM
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26 Gas needle setting right?
I need some advice from the experienced guys:
I ran in the 26 with a Bisson inverted Pitts Muffler opened exhaust tubes, 17x6 APC, 1:32 Mobile 1 MX2T for about an hour.
Initial setting and tuning for run in as per Pè's instruction.
Sparkplug during run in with brownish colour. A lot of black stuff on the plane.
Starting to tune for flying as per Pè's instruction, same fuel.
I get at 4500ft altitude and 30°C outside temp about 8600 RPM with the 17x6.
Sparkplug is getting greyish on one corner and has on the the same side small sandkorn like residue - guess its getting lean but which needle to tune next.
Could not tune some more - ran out of time.
High needle 1.5 turns out, Low needle 1.75 turns out.
Will be flown with APC 18x6W or Mejclik 18x6 - have both.
Does it sound about right for you?
Thanks,
Chuck
I ran in the 26 with a Bisson inverted Pitts Muffler opened exhaust tubes, 17x6 APC, 1:32 Mobile 1 MX2T for about an hour.
Initial setting and tuning for run in as per Pè's instruction.
Sparkplug during run in with brownish colour. A lot of black stuff on the plane.
Starting to tune for flying as per Pè's instruction, same fuel.
I get at 4500ft altitude and 30°C outside temp about 8600 RPM with the 17x6.
Sparkplug is getting greyish on one corner and has on the the same side small sandkorn like residue - guess its getting lean but which needle to tune next.
Could not tune some more - ran out of time.
High needle 1.5 turns out, Low needle 1.75 turns out.
Will be flown with APC 18x6W or Mejclik 18x6 - have both.
Does it sound about right for you?
Thanks,
Chuck
05-23-2006, 05:08 PM
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RE: 26 Gas needle setting right?
RPM sounds good for the Bisson.
Keep the oil mixture at 3% (1:33). Your initial mixture was good, no need to change. So set back to original running in settings. You might open the H needle a bit more to 1-3/4. Power should still be at best rpm, but on the verge of going downhill.
The black stuff will go away in due time. This is normal for most gas engines, and is worse in lean set engines which run at elevated exhaust temperatures.
Keep the oil mixture at 3% (1:33). Your initial mixture was good, no need to change. So set back to original running in settings. You might open the H needle a bit more to 1-3/4. Power should still be at best rpm, but on the verge of going downhill.
The black stuff will go away in due time. This is normal for most gas engines, and is worse in lean set engines which run at elevated exhaust temperatures.
