I recently put a new top end on my 05' YZ 250. The bike sat for a year before the top end job. Now, when the bike is under load and wide open it cuts out terribly. If you are under lite accerelation it is okay. As soon as there is a load put on the engine, or it is held wide open, it cuts out and a acts like it is missing badly. Thus far we have tried: new plugs, new cdi, new coil,checked reeds, repacked silencer, checked flywheel, fuel from gas tank to carb, checked and cleaned exhaust valves, cleaned carb, checked jetting which is stock, tried a different main jet. After all of this it is still doing it. Live in Apple Valley, Ca. Please help if you can.
Bike: 05 YZ 250
Main Jet: #178 Pilot Jet# #50 Jet needle: N3EJ Power Jet# #50 Thanks, Doug