i have a 78 carabella and i just bought a brand new carbuerater and magneto/coil. and it will start up and as long as i keep my speed up i runs fine.but as soon as i give it 1/2 or less throttle it dies. i have tried too adjust the idle screww and the cable at the top of the carb but i still wont run at less than 1/2 throttle. i dont get it it has a new carb/air filter. does any one else?