I have seen some threads on engine upgrades. In several of them they refer to heat cycling the engine. What is this?

 

I think you're referring to this which I copied off another site: Breaking in your motor is vital to the life of your engine. Axtell’s recommended method of break-in is to heat cycle the motor. Start the motor (with plenty of air blowing over the motor to dissipate heat) and allow it to run for thirty seconds. Allow the motor to completely cool to room temperature.Once cooled, start the motor again and allow it to run for sixty seconds followed by a complete cool down. Repeat this process, adding thirty seconds each time until you have reached four minutes.Now the vital break-in is done. However, over the course of the next thousand miles, the internal components are still familiarizing themselves with one another, so take special care during that time.Keep your engine under 3500 RPM’s for the first 300 miles, and less than 4000 RPM’s for the first 1000 miles. Do not put a large load on the engine and be careful not to “lug” the engine during the 1000-mile break in period. This pretty much parallels what the Moco tells you when you buy a new bike in order to break in the engine,aside from the initial warm-up/fanning aspect.

Then there is a "plan B" which you'll find here: http://www.mototuneusa.com/break_in_secrets.htm

 

Thanks for the information K Harry.
that is the context in which it was used.
The article seems to contradict the heat cycle theory. a very confusing subject. like anything else that goes on inside the motor, there are many opinions.

 

Good info to have. I'll be needing this in a few weeks after installing FM 107 kit for initial start up. Thanks.

 

We use the 30 second time frame, on the intial fire-off, then we bring the cylinder temp to 150*, twice, cooling in between, all while a fan is running, on the primary side of the bike.
At that point once cooled, we ride the bike in a "normal" fashion, weather permitting, or roll it around on the Dynojet 5-6 miles, slowly bringing the rpms up to about 3500 rpms, then letting off on the throttle, and back up, then back down, etc. Not a joy ride, but rather a specific method to settle the engine.
Let it cool, once again, then we go for a 12-13 mile ride at the same rpms, doing the same procedure.
Unless the client is looking for an initial tune, and the bike has civil manners, we will release the bike to the client at that point.
This has worked here, for us, and our clients for over 2 1/2 decades.
Scott

 

we do 2 30-40 second heat cycles then get on with our normal break in procedure,PM me with your email address and ill get you a break in sheet

 

What is a good AFR for breaking in new engine before tuning?

 

Here is a set of instructions given to me recently after my rebuild.
The builder has a great reputation in these parts for quality work. This is his idea... Works for me !!!


You can use synthetic during the break-in period (Mobile 1 - 20/50) or similar

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1) Start engine, idle only until cylinders warm up. Once temperature is reached, shut off and allow engine to completely cool down. (You can use fans to speed up this process) - (Check for leaks)

2) Start engine, blip throttle constantly during warm up. (Do not go higher than 1500 rpm). Once temperature is reached, shut off and allow engine to completely cool down. (You can use fans to speed up this process) - (Check for leaks)

3) Repeat step 2. - (Check for leaks)

4) Repeat step 2. - (Check for leaks)

5) Repeat step 2. - (Check for leaks)

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Your engine components, (Rings, valves) should be completely seated at this point.- (Check for leaks)

Ride moderately, avoid high rpms, until first oil & filter change (@ 500 miles) - (Check for leaks)