the only company to help me was kyosho usa with the sirio evo3sti motor when i broke the crank,
i got another motor and it was ok and yep broke the crank again so i got another crank and gear the motor differently and its ok but a tad slow.
other motor company's did not help with my motor's
sorry no warranty the motor was run to much.
and ill say again the ninja is the best motor iv ever run.
the bearings the fit of the crank the piston and sleeve the carb all work the best
well to me anyway.
and if something happened the my ninja's id gladly buy more of them.