The_Russian

Hello,

I recently purchased an aircraft with a Fuji BT-50SB that has an unknown amount of use on it. I am going to assume that it has a been flying for a few years, but I do not know how many flight hours it has on it. After tuning the engine, I am getting about 6000 rpm out of a 20x8 wood prop. The engine changes rpms randomly and un-commanded as well when running on the ground. Sometimes I can hear the surging in flight, but that is rare. I am using a 40:1 mix on 87 octane. Aircraft starts and idles just fine. This is my first gas engine and I'm not even sure if it is tuned properly.

Is there a recommended maintenance schedule for the engine that is not mentioned in the manual? Any tips?

Thanks

Tired Old Man

My Feedback: (1)

No real maintenance schedule, but you could remove the muffler and clean the carbon out of the exhaust port and the muffler inlet every 100 running hours or so.

Never trust that an engine was correctly tuned by anyone other than yourself. That's the first task you have ahead of you. If I recall correctly, the Fuji 50 is not really a 50. 43cc's I think. Don't hold me to that. Your gas and oil mix is just fine.

w8ye

My Feedback: (16)

46.5cc

Carpilot

I had a similar surging problem with my fuji 64ei once after many flights. the RPM's would "surge" except at idle or wide open throttle. the problem turned out to be the fuel pump in the walbro carb was worn. A pump kit fixed it right up.