My M5700 starts and idles fine, but when I put any load on the engine, especially in a higher gear, it dies unless I rev it way up. And even revving it up won't get full power. It does not go above about 2000 rpm. I have replaced the fuel filter, checked the fuel flow, cleaned the air filter, checked mechanical links. It just does not seem to be putting enough fuel into the engine. I had my mechanic neighbor take a look and he is stumped (admittedly, he does not feel all that comfortable poking around modern engines).