Well I did not want to call this thread another one YS 63 FZ S
I've had this engine for a few (6-7) months. This was my first 4-C engine.
After been trying to tune it for all this time, I was not really happy.
It had a great power, but lower and transition was really bad.
Well I though this is my first 4C, plus it has regulator etc, so it is my fault - experience.
Then my passion reached the limit and I sent it to YS Service, as it was suggested by the a long time ago.
It came back after less them 3 weeks.
What a difference!!!
It is completely different engine. All they did is changed couple gaskets and regulator plate.
There is no fuel coming from carburetor and very few (almost non) bubbles in fuel line between regulator and carburetor.
Power, obviously, did not change. But it idle is scary low now and transition is just unbelievable.
And yes it is very easy to tune once you read and follow instructions!!! (Which I know very well after fighting with engine for a few months)
All of a sudden I became better pilot , lower flight and maneuvers, hovering 2-3 times lower height etc so much more fun.
It idles very, very low rpm. Is should probably measure it. But I had so much fun today - who cares about numbers!!!

Thank you YS,
Pashka

Great to hear.

Thanks! and Good Flying!

Dave,
He made a comment about the bubbles in the line between the regulator and carb.
Is this something to look out for?
Does it indicate a problem?
Thanks!
JLK