I have an interesting problem. I have Lanier Stinger 60 ARF with a Saito
80 in it. The engine will not turn max RPM with a full tank of gas on the ground ( Throttle opens completely- No problem). After 2 to 3 minutes of flying the engines speeds up to max RPM and then flies fine for the rest of the flight. Everything about the plane is stock. I checked everything and found nothing. Thinking it was the engine I swapped it out for an OS 60 FX ( 2 stroke) . Now the same thing is happening to the new engine. I am going to swap out the fuel tank and fuel pick up assembly. But at close inspection it looks fine , no leaks , clogs ,airtight etc. It is a standard 360cc tank .It is not rigidly mounted, but rest in a bed of foam with some freedom of movement.Every single person at the field has at least two opinions , but none have solved the problem. I am at my wits end , I love this plane , it is the third one I have had , they fly beautifully. I also know now how to strengthen everything. ARFS are not as strong as the kit version.Experience is a great teacher.
Please help.
ACE