Simjet 3000 low rpm
 

My Simjet 3000 has run faultlessly for a couple of years. I recently flew the same model twice in one day. The first flight seemed to fly as per every other flight I have had with this model/engine combination, but the last flight the engine seemed down on power. Looking at the ECU readings, the MAX RPM is set at 122000rpm but the engine is achieving from 118000 - 112000rpm. Any thoughts as to what is causing this?





John

RE: Simjet 3000 low rpm
 

Hi!
I had the same experience with a 3000 of mine. It wouldn reach max rpm, my setting was 125,000 on max. It was running from 110,000 rpm to 116,000. I took the turbine out for a check, put it into a testbench and made a start. At full power I saw that there was a leak beneath the outer cowling and the kompressor sucked this fuel into its inlet and the rpm dropped. I took off the blue cowling and I did a new start. I saw that there was leaking fuel from somewhere, and with a small flashlight i saw that it was one of the 90 degrees Festo that connect the fueltube with the intake to burnchamber that was defect. I made a new fueltube over the brasstube and put a new Festo on place. Ran it up again and the turbine was performing again. The leak was taken care of and the turbine got the right mixture again. To start the turbine without the blue cowling - loosen the starterengine from its base and hold the startermotor in your hand when you initializing the startprocedure. It worked fine with me :-).

Check out if you can see any leak of fuel at the bottom of your turbine while its running. Then you have the same problem :-). You need a flashlight to identify the fuel due to its transparency.

Good luck!

RE: Simjet 3000 low rpm
 

Thanks, I'll try that.



John

RE: Simjet 3000 low rpm
 

Hi John,

If you have no leaks, it likely is your fuel pump, filter or some other restriction in the fuel delivery or even somethng internally. Things do ware out.

Please contcat me directly if you need fruther assistance.

Best Regards,

RE: Simjet 3000 low rpm
 

Thanks Kerry,
I took the engine out of the model today. There was a thin film of fuel on the bottom of it so I removed the front cover, changed the tubing and festo fittings and tightened everything. It now runs up to 122000rpm, which is the ECU setting. Everything is now as it was. Thanks for the help.






John