Break in after new rings and hone

Hi All

I am well on the way to starting up the old girl after a complete teardown initiated by valve seal replacement.

The Head is on & cams are in. (I dodged a bullet having the exhaust cam lined up with the wrong marks initially, found it before bending a valve stem)

I lapped the valves, honed the cylinders, and replaced the rings to freshen things up.

Can I ask opinions on best break in procedure after such work?

Thanks
Chris

OH boy.... that's opening a big ass can of worms..... LOL

Yes, an apparently simple question with a lot of differing opinions.

Racers have their own way of doing it, but then they aren't expecting 20k plus plus miles from their motors.

Remember engine braking is as important as open throttle: the rings get a good workout when the throttle is shut.

IIRC Kawasai recomend no more than 4k rpm for the first 500, then 8k for the next 500 miles. This is on a new motor, just replacing rings in used barrels probably needs less.

Most important thing is to re torque the head bolts after the first full heat up and cool down. I would replace the oil after the same, but some don't. As for ring seating: ride it. As long as you are going up and down through the gears and varying RPMs ( like typical city riding), the rings will seat. I remember always being advised to do some "up downs" where you take it up to maybe half redline RPM in second gear and then let the throttle off and let the RPMs drop back down then repeat. That forces pressure onto the rings and sets them into the cylinder walls. For the first 500 miles, I would use 1/2 redline as the maximum RPM limit.

couldn't have said it better.
Steve

bountyhunter wrote: Most important thing is to re torque the head bolts after the first full heat up and cool down. I would replace the oil after the same, but some don't. As for ring seating: ride it. As long as you are going up and down through the gears and varying RPMs ( like typical city riding), the rings will seat. I remember always being advised to do some "up downs" where you take it up to maybe half redline RPM in second gear and then let the throttle off and let the RPMs drop back down then repeat. That forces pressure onto the rings and sets them into the cylinder walls. For the first 500 miles, I would use 1/2 redline as the maximum RPM limit.

Sounds good to me! Thanks!


Chris

You will get many opinions, and they may vary greatly. However, take it from me, here's how NOT to break in rings....

I've seen that one. There's one in every bunch.
Steve

The standard break in for any combustion engine is to use a tall gear, like 4th gear on a kz, and run up to 60 mph with lots of throttle and then let off and coast down to 20mph and just keep running up and coasting down for a while. Normal riding is ok as long as you try to vary your engine rpm all the time. The risk of not doing so is glazing the rings or cylinders, in that case they would never quite seal up and you would have to deal with on going oil consumption. There is a difference between how cast iron rings and chrome moly rings seat. If the ring's manufacturer has a procedure follow that.

There are a million very passionate opinions on what honing surface is best and how to break in rings, but the load-coast-load method is the most basic.