return it and get a o.s. .18 CVR awesome power and reliabilty.Direct fit just cut the crank or you can buy the short crank version.Traxxas clutch fits rite on,I got over seven7 gallons threw the one in my pede and still has good compression also very good on gas.Hell put a t-maxx tank in your pede you'll get 20+ min run times and wheelys on demand... like 24t clutch bell and 64t spur 50+ mph lol no problemo i put my rx batt up front zipped tied to my rpm bumper only way i can get controll. way BETTER than traxxas 2.5R u wont regret it