Is there a ideal weather conditions for breaking in a engine?

Lewis

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Should breaking in a new engine be done in the summer or spring when its not cold out? If done in the winter or fall can it be bad for the engine?
 
Should breaking in a new engine be done in the summer or spring when its not cold out? If done in the winter or fall can it be bad for the engine?
As long as you let your engine warm up, it doesn't matter. You'll have to jet up and down as the temperature changes, but you'll have to do that regardless of break in status.
 
What would you say is the most important things during engine break-in? Besides getting the right amount of pre-mix, going below 20mph, and warming up the engine.

Can very small minor mistakes, make a huge difference after break in?
 
What would you say is the most important things during engine break-in? Besides getting the right amount of pre-mix, going below 20mph, and warming up the engine.

Can very small minor mistakes, make a huge difference after break in?
Load. There must be some decent resistance for the engine to work against. This keeps pressure up in the cylinder during the downstroke so that the rings seat properly (and that's all that breaking in is!).

I would not keep speed below 20mph because that would be a very light load.

Idling does not provide any resistance, any load.
Running the engine at full throttle with the clutch lever pulled does not provide any load and would be a major mistake.
Motoring down hill does not provide any load and can cause the RPM to climb to excessive speeds.
Engine braking does not provide the load we want in the presence of plenty of lubricating oil and cooling fresh gas.
Dawdling, pootling, put-putting around at 20mph virtually does not provide any load to seat the rings.


Acceleration and hill climbing provide load, and after a few rides higher speeds will provide load too because of the air resistance at higher speeds.

The ideal IMHO (or my basic underlying pattern, with obviously lots of exceptions as the road dictates), is to start the engine and accelerate at three quarter throttle up to 4500RPM then pull the clutch close the throttle and kill the engine,
pedal until speed drops to 15mph, start the engine and accelerate at three quarter throttle up to 5000RPM, hold it around there for a few moments, then pull the clutch close the throttle and kill the engine,
pedal until speed drops to 15mph then start the engine and accelerate at three quarter to full throttle up to 5500RPM, hold it around there for a few moments, pull the clutch close the throttle and kill the engine,
pedal until speed drops to 15mph then start the engine and accelerate at full throttle up to 6000RPM, hold it around there for a few moments, pull the clutch close the throttle and kill the engine, pedal until speed drops to 15mph, etc. etc. You get the drift. :)

The maximum RPM you get to can increase each ride, as you get through the break-in stage, and you can finish above 8000RPM if your engine allows, basically be making full speed runs by the time you mix some 32:1 and think about jetting the carb for more ideal a/f mix.
You can accelerate pretty hard when the engine has warmed up enough to let you, it's just more lovely load to seat the rings. :)

Do check the torque on all nuts before or after each ride.
Do re-torque the nuts on the head studs after the first ride.
Do have some supports holding the muffler to the frame.
Do run the a/f mix rich during break-in stage (only just running is fine).
Do check everything, and never regard any list of checks as complete or exhaustive.
 
Should breaking in a new engine be done in the summer or spring when its not cold out? If done in the winter or fall can it be bad for the engine?
It's gonna be like aviation and every thing else sea level 78°
But 1 or 2 gallons of gas is not a break in typical top speed like 21MPH 800 to 1000 miles is broken typical speed 27 to 33.8 MPH
 
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