heat cycling
 

Please let me know how you understand "heat cycling" and how you heat cycle a new or overhauled engine.

Many thanks
Doc

If I remember correctly, you do three heat cycles of bringing the engine up to normal operating temperature at medium load for 15 to 20 min then let it cool completely. I thought it had something to do with annealing / reducing internal stresses in new engine components.

Although that is directly opposite of what I have been told by engine builders for break in of 2 stroke engines with plated cylinders that have the correct build clearances. Warm it up and ride it like you stole it because you need heat and engine loading to properly break in the rings.

Thank you.
I have been told that some people let the engine run two minutes and blipping the throttle, then ride it 10 minutes and let it cool down 24 hours. Then they repeat that twice to have three cycles altogether.

It has been said the only reason is to reduce internal tensions (hope that's the correct term) in the material structure.

The ride it like you stole it theory, we all have heard about Moto Man brake in procedure, has a different reason. As you say it has to do with the rings and how they bed in...

My practice has always been to warm the bike to operating temps, shut it down and check for any leaks and check cylinder bolts are still tight. Then ride for 5-10 minutes on flat ground, varying the throttle position, no constant throttle, or high rpms, and no heavy loads. After that I will take to the trail and ride it as I normally would. I've done this for several top ends on various 2t bikes with no issues.

the method i have always used (and posted here numerous times with all the backup info) is to warm the bike up and then slowly run through the gears changing at 1/4 of max revs and then using the engine braking to go back down the gears, then repeat at 1/2, 3/4 and full and you're done

Heat cycling is way overblown. Been rebuilding engines forever and complicated heat cycling procedures are not needed.

Fire up bike, do not blip the throttle at all (don't risk a cold seizure), let idle until up to full operating temperature, shut off, let cool to ambient temperature, check for leaks, check and re-torque head/cylinder bolts if necessary, heat cycling is done.

Agreed.
I've never done any type of heat cycling.

Metallurgy has improved ten fold in the past 30 years.

Exactly! If something is going to fail with today's metallurgy then it was just going to fail no matter what you do. Plus, we aren't dealing with brand new engines anyway. Almost every part inside has already been heat cycled 100's of times.

Thank you guys, appreciate your answers and different opinions.
Just as a modest remark, I did not ask if heat cycling is necessary, I just wanted to find out which different methods are used. :)

Thanks again!

Doc

Um, that's kinda like saying I'm not sure if Homeopathy is effective but I want to know if I need to bang the dilution on a horsehair paddle to invoke the water memory.