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Not Factory Recommended Break In

scottmanesis

scottmanesis

Member
I am just curious what other think of my break in procedure that I will never admit to doing should an issue ever rear its ugly head and they try to blame it on this procedure.

I have done this procedure on every brand new bike I have owned and never had an issue with it and the motors all held up long term.

So here it is

New Bike:

Take it out into a long stretch of open road
start the bike and let it warm up to operating temp
hop on hit first gear and take off
roll on the the throttle until it hits the rev limiter
roll off the throttle abruptly
let the engine slow the bike down to a lug
upshift
repeat until gone through all gears and then reverse the process ( so you do the highest gear twice then downshift)

Pull over, have a beverage, let the bike cool completely

Repeat one time

change the oil

ride as normal

break in time approximately 1 hour including cool time, actual riding about 5 minutes and under 10 miles.

WARNING: This is NOT recommended by the factory but I have never had an issue. My thought and reasoning on this is two fold. If my engine is going to blow up I want to know immediately, secondly if this does not seat things nothing will.

Also, the day your bike came off the assembly line they rolled that bad boy on to a dyno and ROMPED on it before it shipped. It did not blow up then!
 
Not very good for the engine hitting the limiter and then lugging it. It's very hard on the bottom end lugging.
 
IMO it just shows how unimportant being concerned with break in is. Millions of Harleys sold (and rebuilt) and hundreds of methods of break in. NOTHING conclusive about any. I prefer the ring seat/ break in procedure like many on the forum recommend, and I also like a couple of heat cycles. It seems like a logical way to treat new metal surfaces. I don't do a 100 mile oil change, but don't go to the recommended miles either. I do like to hear the "hard" break in methods, just gives me confidence in the durability of HD's.
 
You can mess things up by maxing out the rpm then lugging the engine; things that might not be a big problem until after the two year waranty expires, I prefer the 3/4 throttle rev it up, hold, and roll off; then repeat.

If your bike is factory new the mixture is set too lean and winding it up until it screams just tempts fate.

Bikes and women, make them sing and they will take care of you; make them scream and they will wait until the right time then dump you.

:p
 
Never had a problem with it. BTW I once did a tour of the PA factory where they build CVO bikes, every bike that came off the assembly line they rolled it over to a dyno, strapped the bike in and slapped the throttle silly hitting the rev limiter and holding it for several seconds.

That's why I feel comfortable with my procedure, it was already done to your bike before you took delivery, you just were not aware of it.
 
I have built hundreds of engines over the years. Gliders way is definitely a good way to seat rings, and break the bottom end in, although you really don't need the engine under any loads to seal rings.(accel or decel) Compression, rpm, and heat cycleing is really what aids in proper ring seal.(Assuming the cylinder has been finished properly) Fresh engines that are idled too much will cause the cylinder to glaze, filling the cross hatch and plateau finishes of the bore before fileing the rings to fit the bore properly. If you only resealed the cylinders and the bottom of the engine has lets say 40k on it, the rev limiter isn't a bad thing. If the entire engine is new (bottom end too) then you definitely want to stay away from the limiter until the bottom end is broke in. I run all of my engines on the dyno, heat cycle them well and yes under variable loads before really putting the smack on them. I load them up to break the bottom end in after I have established ring seal. When I fire an engine for the first time I heat cycle it three times, (free load) running it up to 2500-3000 rpms for 4-5 minutes each time, letting it cool between cycles for about 10 min. After this is done I then take leakdown readings. (establishing ring seal) 97% leakdown is very good, and after this procedure most all of that will be going by the valves. (Most of the time I can get 99% leakage, and that is very hard to do) Once I know the rings are sealed I'm home free. I then begin a series of dyno pulls at different loads and rpms to break the bottom end in. Once the bottom end has been broke in, feel free to put the hurt on it. This applies to all engines, 2 cycle, 4 cycle, and even diesels. I have tryed several differnet methods to break engines in over the years, and have the best luck with this method. Hope this helps
Dave
 
Read an article about S&S motors. I believe they do two motors a tight and a standard. Your method would not work on the tight as it requires a long break in and more frequent initial oil changes. They also said that if you are the sort of person who cant resist that right twist grip then go the standard. No real difference in performance between the two just in longevity, that piece of string again. There are some interesting articles on break in on the web. A gent who i believe has a following in the US and builds hot jap motors uses your method and is apparently successful. I have seen pics of v 10 BMW motors on the dyno with the exhaust and manifold cherry red pre fitting to cars. The company i work for has recently bought a lot of C15 powered (Cat motors) they are limited for the first 5000 ks to 1500 revs. Just an old engineering adage 95% of engine wear happens in the top 5% of the rev range!
We need to ask someone with 300000 ks on their Harley as to what method they used!
 
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