Help please!...Thunder Tiger F-54 S main needle setting?

Oct 13, 2005 3 Replies

Hi All,



Ran in this Thunder Tiger F-54 S engine on 15% pink with an 11x5 prop on the bench as in the instructions. Also, the instructions said to open the main needle about 2.5 turns rich for run in and on about the third tank of fuel begin to bring it in to its normal setting. Well I found that the normal setting was not a lot less than 2.5 turns out, say 2 and 1/4.



That was fine and I installed the engine into the model but next time I tried to run it it wants about 3.75 turns out to run properly. Surely this cannot be right. I have never heard of a needle so far out? I'm using the correct glow plug, a 11 x 5 or 11 x 6 prop, 15% fuel, the mid range is adjusted correctly for snappy throttle up, tank in the plane is fine in all aspects. I checked the valve clearances and even popped off the head to have a peep in but no difference.



I even returned the engine to the bench with the bench tank etc to try to simulate the 2.5 turns condition but no go, still 3.75 or so. This cannot be the correct setting as the instruction manual calls for 2.5 as being rich for run in!



Can F-54S users tell me what is the setting on their engines and why you think this engine is at 3.75?



Thanks.



Declan.


Sounds like there may be something in the needle area causing a restriction. You may want to remove the needle and flush some fuel through from the tank side.

Did you notice that the engine ran fine on the bench, but your troubles began when you installed it in the plane? I'd carefully check your installation. The 3.5 turns out indicates the engine is starved for fuel, and I believe this is a clear indication of a pinched fuel line.

A remedy for this situation is to get a tank with a tounge on it to prevent pinched lines like:

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I also like this arrangement due to the elimination of the internal vent line.

Finally, I believe you misread the mfg's instructions. After an initial tank or two of fuel, the running in should be done while flying the plane adjusting the needle valve on subsequent flights.

Ciao,

Mr Akimoto

Took it out and returned it to the bench to its origional installation...same prob

DEclan

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