2015 Yamaha 250 Four Stroke

by Tim
(Twin Falls, Idaho)

This motor has run like a top for the last four years.The motor runs great on 80% throttle however I took it up to 100% throttle and the motor completely shut off. I fired the motor right back up and ran fine as long as I keep at 80% throttle. This is the first time this has done it on this boat. I recently changed the oil filter and the lower unit oil and a fuel water separator. The boat motor pisses fine. Are there top end jets on these motors that could be clogged from bad fuel?