Break-In Period

[Ruger761]

Interesting that this thread has been revived after all this time.

The most surprising break in (and operating!) procedure I've seen so far was for my John Deere garden tractor. The manual's recommendation? WOT from cold start and leave it there. I just couldn't do it. Even now we warm it up at about 1/3rd throttle for a couple of minutes before hammering it.

Speaking of that, I've heard it's a bad idea to warm up an engine by leaving it at idle for extended periods. Besides the fact than an engine under no load will generally never "warm up" anyway, what is the specific problem with warming up at idle? I've taken to warming up with some throttle puttering around the lake for a few minutes in the morning, but it would be nice to know the theory behind the practice.

WOT at start up can be a bad idea due to lack of oil on the top end of the motor and in all of the bearings. Little idle warm up period is highly suggested if nothing else but to get oil to all the places on the motor.

The reason most will say not to leave them idle for long periods is carbon build up. At idle they dont get the same turbulent flow into the intakes, cylinders, and out the exhaust which can lead to more carbon build up. So if you do leave for super long periods it is best to drive it at high RPMs to blow the carbon build up out to prevent any long term build up. Spark plugs typically will last longer as well at full operating temps and rpms vs idle and building carbon.

[IDBoating]

Good observation about the carbon. I'm more sensitive to that in my two-stroke engines but four-strokes definitely aren't immune. BTW, I run SeaFoam in all of my marine engines which does seem to keep things sparkly clean.

[Ruger761]

SeaFoam is some good stuff!!!

[IDBoating]

I just bought this season's two gallon supply at NAPA. They carry it in gallon cans - well, plastic jugs as of this year. A trifle expensive but worth it.

[Ruger761]

Dang, I'll have to check that out I didnt know you could buy it in gallons, thanks for the info.