make sure your heater plugs are working,disconnect the leads to each one and flick a live 12v feed onto each one,if you dont get a small spark at the plugs then replace,another area to look at is the hand primer assy on top of the fuel filter and the fuel heater next to it,these sometimes draw air into the system,one more is the fuel pipes running down the rear of the engine,bad for chaffing and rubbing there,hope this helps,maybe not your fault but worth a look
cdc, October 2010