break in procedures

[jordan83]

how do you guys break in your new top ends? thanks

[Rota Ash]

warm it up, stay in tall gears with lots of wide open throttle and not to much revs

[G-MONEY]

 When I break in a new top end I place a fan in front of the radiator start the engine with the radiator cap off. Keep the r.p.m.s down just off idle until the water is very warm to the touch (bath temp.) Listen for any abnormal noises ticking, thrashing ect.Let it cool down completly.1hr. Repeat this two more times.Pull the expansion pipe,use a flash light an examine the piston. Look for any scratches or shiny spots.If the piston looks good go riding and start the jetting process which you can find on the web probably on this site as well but I new here.2-STROKES RULE

[evo550]

My running in procedure consists of warming it up on the line, slow first lap of practice under the yellow flag, then it's ON!
Come first moto time, we're all good to go.

[Chokey]

Break-in depends largely on the type of piston you use. If you install a cast piston (OEM, Vertex, ProX, etc) then very little break-in is required. A single heat cycle, and a few minutes of heavy throttle with moderate rpms for ring seating is all that is necessary.

If you use a forged piston, break-in is a little more important. Forging by it's nature produces a part with trapped internal stresses that need to be relieved. Heat cycling is vital to relive those internal stress points.

This is the appropriate method for breaking in a forged piston:

From Moto814

1) Assemble the engine properly and torque all fasteners to specs.

2) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the raidator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), shut it off.

3) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.

4) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the raidator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), shut it off.

5) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.

6) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the raidator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), take the bike off the stand and put it in gear. Take it for a ride. During this ride you want to keep the engine under a load at all times. Do not coast. Do not let the bike idle. Do not allow the engine to stay at one RPM. Riding on a mild slope is fine for this, as is slightly dragging the rear brake the entire time. Do this for about 15-20 minutes. Then shut the bike off.

7) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.

8 ) Re-torque the head and base nuts.

9) Go ride.

The cool-down steps are crucial to this operation. You must let the engine cool completely for the break in process to work properly.

Also, do the warm up procedure I outline here before EVERY ride. Your top ends will last much longer if you do.

-Steve

[Hondacrrider]

Ok, i have a 2001 cr125, and I am putting in new clips, top gasket and bottom, and new rings, all of this is oem, what break in procedure should I use?

[juliend]

Chokey's method up there is for breaking in a forged piston. If you're just seating rings, see the 2nd post in this thread.

[Chokey]

Chokey's method up there is for breaking in a forged piston. If you're just seating rings, see the 2nd post in this thread.

I addressed that at the beginning of my post.   

[juliend]

Yup, just re-clarifying for the reading impaired. 

great post, btw!

[RideRedMx2]

Break-in depends largely on the type of piston you use. If you install a cast piston (OEM, Vertex, ProX, etc) then very little break-in is required. A single heat cycle, and a few minutes of heavy throttle with moderate rpms for ring seating is all that is necessary.

If you use a forged piston, break-in is a little more important. Forging by it's nature produces a part with trapped internal stresses that need to be relieved. Heat cycling is vital to relive those internal stress points.

This is the appropriate method for breaking in a forged piston:

From Moto814

1) Assemble the engine properly and torque all fasteners to specs.

2) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the raidator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), shut it off.

3) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.

4) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the raidator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), shut it off.

5) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.

6) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the raidator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), take the bike off the stand and put it in gear. Take it for a ride. During this ride you want to keep the engine under a load at all times. Do not coast. Do not let the bike idle. Do not allow the engine to stay at one RPM. Riding on a mild slope is fine for this, as is slightly dragging the rear brake the entire time. Do this for about 15-20 minutes. Then shut the bike off.

7) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.

8 ) Re-torque the head and base nuts.

9) Go ride.

The cool-down steps are crucial to this operation. You must let the engine cool completely for the break in process to work properly.

Also, do the warm up procedure I outline here before EVERY ride. Your top ends will last much longer if you do.

-Steve

This is how i break in all my motors and have never had a failure