the only reason i can see your motors wont start if your flywheel is loose would be one of 2 problems.
1. the loose flywheel is allowing an airleak in the front bearing. NOT A GOOD THING. and locktighting the flywheel bolt is only a bandaid, not a solution.. if your flywheel gets loose and you have an airleak, the front bearing is toasted i would think...both front and back should be SEALED bearings so no airleaks,, flywheel or no flywheel...
lets hope CENRACER gets in here and mentions the real deal.... if there is a problem with leaky front bearings, i truely hope CEN rights this issue quick, or there will be alot of unhappy customers with roasted engines do to possibly faulty bearings....
2. the ONLY other reason i can think of, is if the flywheel, while it is loose, is Binding up and creating some major DRAG on the engine, thus stopping it from starting/running properly.

EITHER one of these reasons are BAD, and the bearing issue in my opinion would be a warrenty issue. if its binding when loose, then that COULD be a warrenty issue, if its not isolated events.

i wouldnt just take it as a mishap with 2 stated cases, even though theres alot of ct5s out there... im sure others have had this issue but, we ve not heard much of it....
CENRACER.. any ideas you have?
i m taking my CT5 out for tanks number 5-8 tomorrow and going to start tuning it up...

Timmahh