Soften top end hit

[stay_upright]

How do I soften the hit from the top end of my EC300.

It's only high engine speed and wide open throttle I want to change - it's got to be main jet size but richer or leaner?

Main is currently 178 if that makes any odds.

 

[stay_upright]

Ignore his and if mods see it feel free to delete - I found my original post in carburation forum.