Im tryen to see if anybodys had similiar problems with there 14 450s. i just put a new spark plug in a week ago. its got aproximately 150 hours. Its hard to start couldnt get it to kickstart yesterday i had to bump start it. When i get it started it idles fine but when i go wot it backfires and bogs at higher rpms. Ive only used 91 premium any help is apreciated.