see my Photo; my Idea worked, I just need advice on the Idle Screw
Guys, see my photo, remember my other post, whereby I could not find a Header that will work on my ShoeString, well I came up with another idea, it's an odd muffler for a plane but my idea worked out great for me, it got the RPM right were I wanted it to be,
know what Tuned Muffler this is ?? LOL, well it's a 50 size Century Heli Muffler (Silent Power Muffler),, but it ant silent. I had a friend welded up an Adaptor for my OS 61FX, and it works, the Muffler may not be perfectly straight but hey, I didn't weld it LOL,
the engine is the OS 61FX,,, fuel is 20% Magnum Fuel, Plug is the OS #8, the weather was cool, around 66,, I'm getting 13,700 Peak RPM with an APC 11X8 Sport on the 20%, and it's not peaky, BTW the fuel is rather old, some 5 or 6 years old,,
the first time I stated her she was really Lean on the Idle Screw, as I come down from full throttle she was so lean at about 30% 40% Stick she had the "Naa naa naa" sound, so I richen up the Idle 1/8th and she was better but still lean but the sound was not so pronounced,, so I then richen it up again 3/16th and she was so rich she would load up, so I closed it just 1/16, at that she runs but she's not constant, she get Rich and sputters badly around Half Stick as I advance the Throttle,
so note that the Idle Screw is now opened 1/4 turn from the First start up with this Muffler.
BTW, too add, I always had a problem with this engine running ruff around Half Throttle, as I type I am wondering if she needs a new O-Ring on the Idle Screw, but if she was sucking Air around the Idle Screw's O-Ring that would Lean her out, this is where I'm confused ??
another thought, I know a Colder Plug is usually used at Higher RPM on a Plane, but not on Helis that have less Flywheel Load at Spool Up, so I'm wondering if the hotter OS #7 would help burn off more fuel around Half Throttle with this Muffler, what is your thoughts on that ??
as for the High End Needle, once I find the peak RPM how much do I richen her up, I was opening it up a bit more than 1/2 a turn once I found the Peak
so where do I go from here ??
thanks guys !!!
Jim