Give the saito awile to get broken in. Also keep the throttle setting low for the first break-in tank or two or you'll be chasing your prop.(or getting chased, if your in the wrong place at wrong time!) Have seen saitos throw prop spinner locknut and all when run too fast too soon. will also be a little picky about needle settings. Be patient and you will be rewarded with one heck of a stump puller.