I have changed the O-ring on my starter, and when running it manually
by pushing the Ignition-button, it runs very strong and fast, but when I try
to start the turbine, it only runs up to 2-3000 rpm and in 2 seconds I get the
warning "Low RPM". Then the starter starts and stops for very short intervals
until I shut off the power.

Does anyone have a clue to what's wrong??

Thanks!

Tor

Now that you have changed the o-ring and probably made sure there is no oil or grease on the o-ring and spinner, It could be the starter motor itself.
Bring it to the clubnight on monday and we'll have a look.

Hello Tor,

I had the same problem exactly. This is only a problem when you have a KEROSTART and not with gas start. I called Max at Jetcat Germany and he guided me through the GSU menu to set some locked parameters in the ECU. Call him and in 5 mins it will be fixed. Its an ECU issue.

Good luck.

Tassos

Max doesn't work at JetCat anymore unfortunetly[]

Tor resolved the problem. I'm sure he will chime in and tell what it was...

Check your ramp up starting pulse(Ve). If it runs as it should when in manuale push button mode, then Like Tassos said it's a param in the ramp up cycle of the ECU.

Really, where did he go?

The problem was solved: I had removed the starter bullet to change the O-ring. To remove it completely,
I had to solder off the leads for the starter motor. When I soldered these leads back on, I routed the brown
cable over the connector for the black "telephone cable". There, it was lying across the print plate and a black
"blob" that may be a sensor of some kind. Moving the brown cable back and forth gave me readings from 0-
4.000 RPM although the turbine was not running. Routing it the other way around the intake gave me a constant
reading of 0 RPM and a clean, smooth start sequence! Little things obviously matter in turbine construction!!

Thanks for the suggestions!
Tor

TorGreat. Yea the manual run-up is a Diff circuit than the auto ramp up. In order for the ecu to know when to ramp in fuel it has to read rpm from the gas burn. Basically. Man those little easy fixes can run you craze for an hour or two!!! ha. Blus Skies up there man!! Roy

Building rocket engines (serious!)