My kits all come from zminglu, rose326 and mingsinternational on fleabay. (same vendor)
Over 20 kits with no lemons and the only two issues I've had were two bad coils which were replaced free and fast.
If you want a better quality engine, try motorbicycleracing for his new Gen V "balanced" long block.
At $150 it's a great replacement for the kit motors. Much quieter and smoother running than the usual chinagirl.
Dax also sells a "balanced" motor, but I dislike the "Made in America" false advertising.
They have been getting good reviews as well from what I have read here.
