I have a predator 212cc engine, the problem is when I go to start the engine the pull start is so hard to pull out that it lifts the back end of the mini bike. So what would it to be so hard to pull start? also I just took out the sparkplug to see if any fuel was in there it was clean and dry and cord pulled with no problem but when put my finger over the hole the cord was hard to pull. so could it be the timing is off and the valves are not opening at the right time.