ORIGINAL: Ernie Misner

It may be tuned slightly too lean and / or is tending to get hot with the cowling in place. If it runs fine without the cowling then there is definitely something wrong with the air flow when the cowling is in place. It may need more break in time as well. You can try increasing the size of the openings or fly it without the cowling altough you don't want to for some reason. Try richening it up a little and see how it goes. Keep us posted.....

Ernie Misner