New engine break-in

Hi all

I was reading this internet article at a website "mototuneusa.com" and this guy is recommending a method of new engine break-in that supposedly contradicts what Harley recommends (Haven't read the manual because I haven't picked up the bike yet). He is saying that the first 20 miles or so are critical, and if you don't break it in right the engine will never develop the power it is capable of, and for street break-in he is recommending alternately accelerating and deccelerating hard through 2nd, 3rd and 4th gears. Then dumping the oil shortly there after. Also he says that you should be running a 10w-40 mineral oil during this period as apposed to a synthetic. What are your thoughts on this and what type of oil will be in the crankcase of my new ride? He goes on to say that it also is very important that the engine be warmed up before going through this process which is quite understandable so another question that I would have is........about how soon are these engines up to operating temperature. When I pick it up I'll be riding a few blocks to get out of the city, then out onto the highway. Obviously if the Road Kings had a temperature guage then I wouldn't have to ask this question but.........

Thanks

John

Chucks right man... Use the manual... Gotta get the rings to seat properly and other mating parts too. I'd also change my oil according to the manual after breakin. Take care and enjoy!!!

I Would Do It Like The Mfgr Says To, They Know There Motor, Allthough Had A Gut Tell Me Before After About The First Hundred Miles Ride It Like You Plan On Ride'n It Every Day After The Breakin Period, Me, I Did It Like The Book Said.

Yeah, I've read that too & wouldn't disagree much - EXCEPT - did you notice what TYPE of bike he was talking about? Comparing a liquid-cooled, thermostatically-controlled, short-stroke even-fire Japanese bike engine to a Harley is not even as close as comparing "apples & oranges".

I disagree with H-D's procedure in some details, but while the mototune guy says "heat-cycling" is irrelevant & it pretty much is for that type bike, it most assuredly is not for a H-D engine & if you go by what H-D says, you shouldn't have any problems. I just break 'em in a little sooner & harder & he's right that the rings should seat quickly.

But a big deal is the engine parts are made of different materials which expand & contract @ different rates as they heat up & cool down & a H-D engine runs over a MUCH wider temp range than a liquid-cooled, thermostatically-controlled engine does. Add in factors such as long stroke vs. short, small pistons vs. large, overhead cams vs. pushrods & rocker arms, etc. & you soon see what applies to a 600 cc Kawasaki, etc. does NOT apply to a H-D.