There are several theories on how to break in new rings: One is the old-school way of taking it easy at varying RPM for the first while.
Another is to work it fairly hard as soon as it's up to operating temperature.
From the Hastings Piston Rings suggested procedure:
"1. Set tappets, adjust carburetor and ignition timing as accurately as possible before starting engine.
2. Start engine and set throttle to an engine speed of approximately 25 miles per hour (trucks, tractors and stationary engines one-third throttle) until the engine coolant reaches normal operating temperature. Then shut down engine and retorque cylinder head bolts, recheck carburetor adjustments, ignition timing and valve tappet clearance. (Run engine at fast idle during warm-up period to assure adequate initial lubrication for piston rings, pistons and cylinders.)
3. Make a test run at 30 miles per hour and accelerate at full throttle to 50 miles per hour. Repeat the acceleration cycle from 30 to 50 miles per hour at least ten times. No further break-in is necessary. If traffic conditions will not permit this procedure, accelerate the engine rapidly several times through the intermediate gears during the check run. The object is to apply a load to the engine for short periods of time and in rapid succession soon after engine warm up. This action thrusts the piston rings against the cylinder wall with increased pressure and results in accelerated ring seating.
A third is to really work it
hard as soon as it warms immediately after starting with new rings. Check this out:
http://www.mototuneusa.com/break_in_secrets.htmThere are as many opinions on how to do it - and opinions on why any other way is insane - as there are Harleys at Sturgis.
