I am just back from our club field, and I am puzzled and frustrated... especially beigs I claimed my new Super Tiger G-61 ABC was broke-in and Tuned PERFECTLY at home, then went to the field after changing from a std prop to a pusher prop, and I had 15 guys eyeballing a totally new aircraft for our club, with this supposedly perfectly tuned engine from an hour before in my driveway, go figure...
YES the motor was taken through the OEM break-in routine, yes by the book, and yes with a standard 11x7.5 prop, yes as the book states, 5 minutes full throttle and tuning high speed needle to not be too rich and not too lean for the ABC engine break-in, than after 5 mins, did the low speed, midrange, PERFECT PERFECT and ran it for 20 minutes on and off for an hour with 2 tanks fuel. NEW gallon of Omega 15% pink half and half synthetic and castor. IT was flawless, perfect with std prop 11x7.5
I tuned it with a standard 11x7.5 prop.
Then I put on the APC 11x7P pusher prop and headed for the field, then guess what, the midrange is too rich and the stupid thing would NOT tune. IT was hard getting to full throttle past the rich mid-range, then would stahl and shut down, what the HECK???
OK, here is the story:
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I have a Bobcat 50 setup with a new ST G-61 ABC, which is a pusher prop Jet.
Similar to this, but not a 75
http://www.rcdon.com/html/the_bobcat-75_project.html
So what happened between the standard prop vs the pusher prop???
Yes, I used a standard 11x7.5 prop to break in the engine BECUASE the pusher prop (11x7P) will NOT cool the einge sitting on the ground, because the airflow cooling on a pusher is about 80% to 90% less cooling due to the air going the opposite direction.
So, one of the seasoned guys is thinking the pusher maybe setting up a different draft and maybe causing some suction out of the carb or some strange dynamic??? He is thinking I need to make a snout or tubing to connect to the carb and route it back some to get the suction from the pusher out of the carbs face????
What do you all think or know about pusher prop and engine tuning issues?
Would a hotter plug make a difference, becuase I did notice, that with this being my first super tiger, I need to leave the hotshot starter on the glow plug for 30 to 60 seconds and fun the motor to full then back down before I can take the glowstarter off the glow plug, or the engine will slow down and sometimes act too rich, then stahl???
I've been using this same fuel in my two OS engines and thunder tiger engine, no issues, could this fuel not be best for ST G-61 ABC ???
I did Not change the plug, still the OEM plug...
What is the recommened plug for a Super Tiger G-61 ABC here in the North East USE (S.E. PA corner)
I have a stack of NEW OS #8's, some Fox short and fox long standards, then HOT OS LC3 long and a Fox miracle plug?
** Also, on a jet, does the exhause head-wind matter at all once in the air, will this be another tuning crisis and flameouts?
Thank you in advance for any help!!!!
Please post any tech help, this has me frustrated thinking my new Super Tiger was perfect, then change prop and BAM, stupid thing is terrible...