i believe you are talking about www.mototuneusa.com, and, to cut it short, he claims that his break in seals the piston rings better than a soft one, and that prevents acid gases from the combustion to get into the oil, corroding the engine, i find it very interesting and convincing.

Hope nobody minds if I cut & paste some things I've written in other places, but I have just collected my bike with a newly-rebuilt engine from David Lambeth, and I had a good read of that website before deciding how to run my bike in...

First 20 mins of engine life, only DL and his mechanic rode the bike - this is apparently the most critical time - the riding was EXTREMELY gentle.

Idling to full operating temp and then very gentle riding (20% throttle?)

After I picked it up, he said, for the first 500m / 800km no more than 50% throttle.
ABSOLUTE rev ceiling on 4K. No heavy loads. About 60mph in top at the most. I check the oil daily, after I've ridden the bike somewhere (or at each fuel stop) Used about 400ml so far (first 375 miles done) The bike is doing about 45.5mpg, with a 180 main jet, but stock pipe. Yoshi race pipe will be back soon.

Following 1000 miles, I can ride it normally, but not thrash it. Oil consumption should have dropped to almost nil (I say almost because I think all XRs use a bit). Then I will get a Dyno done to check mixture in emissions and refit race pipe. I can posy before and after-seize graphs. Might be interesting.

By the way, this urban myth about modern honing being smoother / finer? Sounds like bullsh*t to me.

The above run-in method is subtly different from the Honda recommendations, but not drastically.

For information:

Engine out of bike.
Strip and inspect: seized and piston holed.
Clean parts and check tolerances
Valve stems and springs
4x main rockers
2x sub rockers
New cam and bearing set
Gaskets, seals, lock washers, fastenings,
Gearbox bearings,
New piston (Honda) rings, pin, clips
First interval rebore (0.5mm I think)
Crank rebuild:
new con-rod, bearings, etc

The bike runs at between 150 and 220 deg F. Is this consistent with other XRLs?

http://www.horizonsunlimited.com/ubb/smile.gif

Lewis
www.PM-04.com