Merlin 100xbl Not reaching full RPM
 

Hey guys.. I bought a used engine that will not goto 152,000 as its supposed to. I don't want to have to return it as its been a month or more, but I have only got 3 flights on it and its not pumping it out!

Max RPM is 145,500 The fuel pump is new. 7hr on engine. Good 7.4 lipo to run.

I called him and he said to make sure that the ECU was set to 152,000. It was set lower and I upped it.. but then why is it not hitting max rpm. Perhaps I didn't lock in the change I made? Did I miss something?

Note the PW of the pump at full throttle. Check in the run menu the "pump limit" parameter value. It should be at least 10% higher than the PW at full throttle. ( The PW will never exceed the " pump limit"), limiting it to about 10% more than max PW, make the engine run smother mainly with big pumps.

I´m assuming that the EGT don´t exceed the max temperature at full throttle, ( this could be a reason too).

Good luck,

Thanks for the reply Felix! Gaspar has replied via email. I will try what he mentions and at the same time take note of what you have suggested. Much appreciated!

From Gaspar....

Hello Trevor,

First make sure that the radio is commanding full power. On the data terminal you should see “Run-Max” when throttle set to full, if you see “Running” then means that the 100% command is not sent, in this case re learn the radio.

If you see “Run-Max” but the engine don’t reach full rpm, keep the throttle at max for over 5 seconds, then you will see “Calibrating” and the ecu will increase the pump until arrive to maximum. If the engine has been run at lower setting, the ecu will take some time to adjust all the parameters again for new settings.


Gaspar

FYI Felix.. the temp never went over 550 if I recall correctly​