2004 Yamaha Motorsports Bruin 350 Automatic Owners Manual - Page 60
2004 Yamaha Motorsports Bruin 350 Automatic Manual
Page 60 highlights
EBU02101 Engine break-in There is never a more important period in the life of your machine than the period between zero and 20 hours. For this reason, we ask that you carefully read the following material. Because the engine is brand new, you must not put an excessive load on it for the first several hours of running. During the first 20 hours, the various parts in the engine wear and polish themselves to the correct operating clearances. During this period, prolonged full throttle operation or any condition which might result in excessive engine heating must be avoided. However, momentary (2-3 seconds maximum) full throttle operation under load does not harm the engine. Each full throttle acceleration sequence should be followed with a substantial rest period for the engine by cruising at lower r/min so the engine can rid itself of the temporary build up of heat. If any abnormality is noticed during this period, consult a Yamaha dealer. 0-10 hours: Avoid continuous operation above half throttle. Allow a cooling off period of five to ten minutes after every hour of operation. Vary the speed of the machine from time to time. Do not operate it at one set throttle position. 6-7