I have an interesting experience, but let me share some figures first:
TT70 hours
new aluminium Cummins Spinner since 6 hrs. Beautifully made, nearly-perfect mounted per manual: even less movement of the pitot than with the original spinner.
New spinner is not balanced, yet.
The spinner-info is added because I never had this issue before I mounted that beauty..
Engine runs fine, temps where they should be. Taxiing for some minutes, run-up flawless. Takeoff nice as ever. Then the prop begins 'shaking' as if it isn't centered. changing RPM always solves it, and the flight is effortless.
Changing RPM's afterwards never ever got me shaking again...
This happens at some 100ft height, and no (read my lips: NO) shaking whatsoever at run-up.
Checked of course:
No loose motor mounts, engine rubbers - nothing.
No wear or tear on the engine-axle (as far as I can feel/see without deep examination).
Today I noticed a little gas stain in the drip pan of one of the carbs.
I thought it was my turn for sunk floats, but one Rotax guru (Roger Lee) said to be careful with quick actions, for sometimes '..it makes the carbs shake so bad the floats and needle valve can't control the fuel level and it vents out the tube'.
That shake is definitely what I got - but how?
Might the (slightly heavier) spinner be the culprit?
And how do I check that?
Any ideas highly appreciated!
TT70 hours
new aluminium Cummins Spinner since 6 hrs. Beautifully made, nearly-perfect mounted per manual: even less movement of the pitot than with the original spinner.
New spinner is not balanced, yet.
The spinner-info is added because I never had this issue before I mounted that beauty..
Engine runs fine, temps where they should be. Taxiing for some minutes, run-up flawless. Takeoff nice as ever. Then the prop begins 'shaking' as if it isn't centered. changing RPM always solves it, and the flight is effortless.
Changing RPM's afterwards never ever got me shaking again...
This happens at some 100ft height, and no (read my lips: NO) shaking whatsoever at run-up.
Checked of course:
No loose motor mounts, engine rubbers - nothing.
No wear or tear on the engine-axle (as far as I can feel/see without deep examination).
Today I noticed a little gas stain in the drip pan of one of the carbs.
I thought it was my turn for sunk floats, but one Rotax guru (Roger Lee) said to be careful with quick actions, for sometimes '..it makes the carbs shake so bad the floats and needle valve can't control the fuel level and it vents out the tube'.
That shake is definitely what I got - but how?
Might the (slightly heavier) spinner be the culprit?
And how do I check that?
Any ideas highly appreciated!