Hehe.... I think I've fixed a 1000 of things in the past 2 years!
My guess would be the exhaust port or the muffler is plugged. Remove the two bolts that hold on the muffler and remove the screen located in the muffler (if there is one installed) then look to see if it is plugged. Then throw it away. Next, look in the exhaust port and see if there is carbon build-up.
Some spitback through the carb is normal on these blowers.
Hankster I couldn't have put it any better.No telling how many folks pitch good stuff over something that simple.Here in the south look out dirt dobber's about worst enemy on small engines and outboard motors.My 2 cent's
re: try riching your low end carb needle up some 1/8 turn at time sounds like its running lean on the bottom, i have raced rc boats for 5 years know and mod my own so i know quit abit about 2 stroks
Got the same problem tried everything including the exhaust screen but which needle valve is the low end and the high end? I have 2, one red and one white - by the construction seems they are inter-related!
The high end is closest to the air cleaner and the low end is closer to the engine. One thing to remember when adjusting needles is that any change on the low end will affect the high end. If you richen the low end you will most likely need to lean the high end.
To explain, the high end is only in effect when you are at higher RPMs, the low end is always feeding gas no matter what the RPM. So if you richen the low end, it also richens the high end.
Start each needle at 1 1/2 turns out and work from there. You should never have to go more then 2 turns on either needle. If you do, then you most likely have some carb bloackage.