Once the gas trigger on the handle is pressed to feed gas to carbirator the engine will cut off imededitly

The curved shaft machine has a flexible drive shaft like a speedo cable, slacken the two tube pinch bolts, these are accessed on the r/h side of the grey plastic handle through holes in the plastic housing,, remove the two mushroom headed screws either side of the plastic handle,don't lose the black o rings under the screw heads, do not remove any of the plastic housing screws, now carefully draw the tube out through the plastic handle/trigger assembly, once out pull out the old drive shaft, grease the new drive shaft and push back into the tube, once fully in turn the end to make sure the trimmer head turns, now feed the tube back through the trigger housing, make sure it is fully back home and the square end of the new shaft has entered the square hole in the drive drum, re tighten the pinch bolts, start the engine, if the head does not turn, slacken the pinch bolts and push the tube further in, re fit the two mushroom headed screws.

Hey Dan, that would be a sticky or broken micro switc in handel if its a miller or Hobart you can replace just that part without buying a new handle .

Can you hear the motor? If you can, tighten the tension on the wheel. If the motor is not runnung, check the trigger switch to see if it's working. A wire in the handle may have broken.

1st add fuel/oil mix to fuel tank , then top off oil tank with bar oil , place saw down on flat surface , press 'ON" button above trigger handle to ON (its marked on case) then pull out blue choke handle till it clicks and stays out , press primer bulb with thumb 8 to 10 times bulb will become harder to press as it fills carb , push chain brake forward (on) ` place left hand on top of saw and right hand on start cord , hold saw down firmly and pull cord vigorsly several times till it sort of starts (sound) , squeeze trigger in and pull cord once more , saw should take off running , chain wont move ,walk to wood pile then disengage the chain brake and cut wood , if saw fails to start after this procedure then there must be a fault in saw , consult a exp small engine dealer for repairs

Looking at the Hobart manuals, that is how they set them up at the factory.

One way to make a change to that is to wire in a solid state relay or solid state Triac and pick up an energizing voltage off of location RC2-1 or RC2-2 on the control board when the trigger is pressed, or as an alternate location from the feed motor through a resistor and rectifier. Once you know if the voltage goes low, or voltage goes high at your point of signal, you pick the contact you want on the relay so when the wire is feeding out, the gas is flowing. and when it is not feeding wire out, the gas is shut off.

Hi:The solenoid valve gets the current once the switch is activated (pressed) therefore my opinion is that you have a sticky trigger. or one of the terminals of the cables it's shorting out.Change the trigger or better yet check that the terminals are clear and not touching other parts of the handle.

check for circuit breaker by drive motor, it may be the pc board.

Sounds like a broken wire in the cable from the trigger to the control board - or the switch in the handle is crapping out.

If it's had a fair amount of use, or has been bent into some seriously oddball or tweaky positions, it might be time for a new feed line and trigger assembly.

there is a safety button[usually by thumb area when u grab handle ] on most saws that has to be pressed as well as the switch when using circular saws

sounds like the float is stuck, if no float in it, then it is plugged and needs to be cleaned or replaced.