The best to overcome the compression on startup is to give the plug a 1/4 turn loose when starting. Once the motor runs tighten the plug and it should be fine. Otherwise ad a shim there should be a copper and a ali one. When you remove them it looks like one but is actually 2. Replace the ali one that is a 0.2mm shim. Should be fine. When the motor has a few hours running you can remove that and replace with the copper one which is 0.1mm. if it still kicks over re replace the 0.2mm.

Enjoy your motor. Watch the oil content in the fuel mix these motors like to spit its main bearing and destroy the motor.