Rotax 447 carb trouble!

dwood2066

Newbie
Joined
Aug 4, 2018
Messages
19
Location
Pampa, Texas
I just took my air command 447 out today. I tried to run it up full throttle on runway and it just sputtered. I pulled off, then ran it at half throttle for a minute and it ran fine. It starts and idles great. Is it the float needle/seat or air/fuel mixture? The motor and carb was rebuilt with 30hrs now. Anyone with same problem and how to quick fix?
 
Running at half throttle OK means the intermediate jet is OK; full throttle takes the main jet. Sounds like there's something blocking the jet. Drop the float bowl and shoot carb cleaner up through every little hole you can find. Open the throttle wide, then shoot the main jet with the carb cleaner.
 
Another item to check if the machine has been sitting for a while..Dirt daubers love to pack rotax mufflers with their mud nests..you will be unable to reach High rpms.
Since it ran fine before and you have not changed anything, don't re adjust the carbs or change jets, check the exhaust for the aforementioned blockage, and check your carbs for cleanliness inside.
 
Don't forget to check the fuel pump. Could be getting enough fuel for lower rpm's but not enough for full throttle.
 
Mine on a ppc did that and it was just a dirty air filter. Took the filter off and it ran fine. The filter plugged up just while sitting. I live in dusty New Mexico and a gravel plant opened up 2 years ago about a half mile upwind of me compounding my dust problem.
 
Top