4-Stroke Engine Break-In Procedure
It is extremely important to constantly vary the RPM’s during break in. Do not let the motor run in one RPM range for longer than 5 seconds and do not let engine idle for first half-hour of operation.
Did you install a new cam?
During cam break-in, you need to maintain an engine RPM of 2500 or more. This is to keep good oil pressure to the new cam.
INITIAL WARMUP/BREAK-IN PROCEDURE
Warm the motor up thoroughly constantly varying the RPM’s until at normal operating temperature, approx 5-10 minutes. Then shut off and let the motor cool completely (probably at least 3 hours).
Start the bike back up and warm the motor up thoroughly again. It is now ok to mildly ride your ATV or motorcycle. Ride about 15-20 minutes and then let the engine cool off completely again (at least 3 hours).
And yes, you’re doing the whole warm up/cool completely process TWICE. It is important to properly break in your new piston/cam.
WARMUP EVERY TIME
From then on, every time you ride, be sure that you warm the motor up thoroughly before riding. The heat cycling of the engine tempers the piston.
For the first tank of fuel, do not ride wide open for an extended period of time.