I had the same problem with my t200 petrol model.Check that the fuel to oil mixture ratio is correct.Check that fuel choke levers are open on cold start.Check that the trigger switch on the handle bar is locked with the red button in down position.If the unit has not been serviced recently,unscrew the small sparkplug at the bottom end for signs of wear and fouling.Insert the loose sparkplug into the pluglead and pull the starter cable to see if the plug is sparking correctly.Do not touch the plug or the plugcable when you do this to avoid a small electric shock which is not life threatening but unpleasant.Check the air filter on the side(black plastic cover)for blockages.If none of these solve the problem then have a technician remove the exhaust manifold to view the condition of the piston through the exhaust port.If the piston is scratched then an expensive rebuild may be required as a worst case scenario requiring the replacement of the entire motor.It may then be more viable to get another brushcutter.Hopefully not,as was the case with my T200.
R.Amien, October 2009