Most guys are using the Harbor freight 6.5 clones there a 159. dollars when there not on sale and if you get the 20% off coupon and get them when H.F. runs a sale on the engines you can get them around 105 bucks with coupon. They are on sale until end of this month for 129. and there a 20% off coupon out there to. Check under cjtmini for adt. plate to mount the engine to your bike if you do not want to slot your motor plate to fit the new engine.