alot of people assume that it's a 670 it's a HO, i've boughten one like that, advertised as an HO. but to use HO motor you need all of the electrics that go with it too, different ignition. the key way is in a different spot on an HO crank then a non HO engine. your almost better off with a non HO motor and build from there, cause to find CDI for an HO or summit x, well they only made the X for 2 years and the HO for one. regular 670 you can use 583 cdi. more common parts and you can make a 670 run harder then a stock HO without too much fuss.
