Engine Break-in procedure

Kennedy_Power

New Member
Apr 8, 2008
642
19
0
Rochester,Michigan
Break In Procedures

1) Start your engine and let idle occasionally blipping the throttle for 5 minutes. Allow the engine to cool completely. Repeat this "heat cycle" process two more times. After completely cooling down, re-torque the cylinder base and cylinder head. Check for any leaks.
2) Warm up the engine again and ride the bike for 10 minutes at a very easy pace, vary the rpm, don’t ride at one speed. Do not run above ½ throttle or RPM. Let the engine cool down completely and repeat the initial break in ride. Check for any leaks.
3) Ride the bike for 15 minutes at a moderate pace, vary the rpm, and don’t ride at more than 3/4 throttle or more than 3/4 rpm. Let the engine cool completely and repeat.
4) Re-torque the cylinder base and cylinder head.
5) Complete the break in by riding at an aggressive pace for 15 minutes, vary the rpm and don’t cruise at part throttle, ride hard, loading the engine without excessive RPM. Ride at a recreational pace, full throttle should only be used for very short periods. Run a 1/2 tank of gas through the engine in this manner to complete the break in.
6) Replace the spark plug with a new one. Ride the bike for 10 minutes at a moderate pace, vary the rpm and shift up and down the gears. Once the engine is up to operating temperature you can make a jetting pass. Start in 3rd gear and ride at full throttle through 5th gear, fully revving out 5th gear. With the throttle wide open in 5th, kill the ignition, pull in the clutch and stop.
7) After a short cool down, pull the spark plug out. Now look at the upper 1/3rd of the insulator, if there are any tiny black specks or shiny specks of aluminum that have fused to the insulator, this indicates the first/beginning signs of detonation that will lead to severe engine damage. Detonation can be caused by excessive engine timing, wrong fuel, overheating or jetting too lean.
8) With a flashlight and a magnifying glass first look at the insulator part of the plug, viewing the plug from the center electrode look down the length of the insulator to its base, at this point there should be a light brown/tan colored ring. There was not sufficient time to thoroughly color the whole plug, so the nose of the insulator may still be white. Now look at the spark plug base ring (the base ring is what the ground electrode is welded to). It also will have a light brown/tan color in time. If the insulator color is white at the base and no color on the base ring, increase the jetting 2 sizes, if dark brown, decrease the jetting 1 size. Return to step 6 as required. Check for any leaks.
 
  • Like
Reactions: Chris280bigborr
someone should sticky these.its comin from the people who know best

Wow that's the bible of how to properly break in a fresh motor Thanks Kennedy Racing i'll be using this to break in my fresh motor.

another killer write up

Definatley the break in method ill use I:I

It was nice of Mr. Kennedy to provide this info to you guys but he should have gave credit to the people who actually wrote it....
Cylinder Break In
 
It was nice of Mr. Kennedy to provide this info to you guys but he should have gave credit to the people who actually wrote it....
Cylinder Break In

Some is the same and other parts are different.
Why would you reinvent the wheel?
How many people have used trans fluid on the cylinder bores for break in
It works better then oil to seat the rings
Is smarter to look over others thoughts and build on it, that’s what I was taught in college
 
maybe Kennedy should in the future just say, I don't know go look it up, thanks for taking the time, more appreciate it than not.
 
im just about to finish my rebuild and im planing to fire it up this weekend so ill be using this method....thanks
 
this is nice to know specially since i am redoing the whole engine but one question do you change gears while doing the throttle at no more than 50%??? thanks Steve