It is at the mechanics for installation of a forged 10.25 to 1 Wiseco Piston and a Webcams 89a cam. It should be ready in 3 weeks.

I'll report back when it is done.

I, and I believe others, will be very interested in what you find out.

A suggestion would be to break it in carefully, use higher octane gas, and perhaps go up one step in the main jet; one step cooler on the spark-plug.

Alexd

This is what I have found works best for break in, a heavy throttle.

This link includes details regarding the hard use break in method. I did it the manufacture's way the first time on a different bike and it led to me doing it the hard use method the next time around... Light break in can really prevent the rings wearing in properly, which is what will kill your performance. I would imagine if you have a guy rebuilding it though he'll break it in for you (or at least tell you what he thinks is best). Stay away from synthetic or any friction additives to start with, and plan on few oil changes in the first 1000 miles or so.

http://www.motorcycleextremist.com/Motorcycle-Engine-Break-in-the-Right-Way!.html

I have no argument with that, except to say that like oil preferences, that's a topic that has adherents on both sides.

Maybe it's best to say that (like Yamaha does on the older race bikes like the TD-1)...run it hard for 5 minutes then tear it down, flush it with oil, and look for wear spots. This of course for a 2-stroke, but with chrome cylinder liners.

Is the XT 4-stroke (or 4-strokes in general) the same way? I don't really know; I do know that liquid cooled high-performance cars cars like Corvette, Camaro, Nissan GT-R come directly from the factory with Mobil One 0W-40 synthetic oil.

Alexd

Hi Alex,
Are those car engines run-in on the bench?

My daughter bought a new Suzuki car and was told they were bench run-in so no need for the 500 mile service, just annual or 12k miles.

My new road Bike has to go in for the 500 mile service with oil and filter changes. Triumph stipulate avoid high engine revs for the first 500 miles then gradually increase engine speeds up to 1000 miles. In other words old school running-in procedure.

Is this "run them in hard" procedure more meant for race engines?

Again...there's many sides to this, and different opinions.

I think I can say that most owner manuals suggest slower break-ins. The GT-R motor is "run-in" for a number of hours on the bench, and the car is delivered with 33 miles on the odometer, from Nissan's test track. I have no doubt that Corvettes and other higher performance cars are similarly treated for their engines.

It could be argued that the slow break-in is primarily for the transmission components...

Alexd

People have different ideas of the best running-in or break-in as our chums over the pond call it.

My own preference is just to keep the motor sounding sweet, not under stress & never labouring. I run-in for approx. 2k miles before using max power.

Each to their own preference though.

As a general rule, auto engines do receive some level of run-in on a bench (aka test stand or dyno). They're all tested for various parameters prior to installation in the car, then they get tested again after installation in the car. The higher performance the engines get a more thorough the run-in because their customers are more likely to notice/complain about minor issues.

Technology has advanced to the point that run-in isn't as critical as it once was as well. Pistons and cylinders have fancy coatings, rings are different design and materials, clearances are tighter and better controlled, surface finishes are better, ... all that stuff adds up to change what it takes to get one run-in.

IMO, older tech engines like the XT need two basic things...

1) Moderate load at moderate rpm to get the rings seated
2) Heat cycles

Start it up and don't let it idle. Keep the revs up a bit off idle and let it warm up for a couple minutes. Then accelerate through the gears at 75% throttle but short shift well below max rpm. Avoid engine braking. Do that a few times then stop and let it cool completely.

Repeat that 3-4 times and change the oil. If there's significant oil debris (big pieces), you have a problem. If it's just "fines", do it a couple more times and the amount of fines you see in the oil should be less (there's always some amount in these things).

After that, I'd ride it normally if a bit gently until it's got about 500 miles, then I'd change the oil again and have at it.

Aye mate,

I remember rushing the run-in on me 600cc Panther M100 in me youth. Then having to do it all again after I caught up with me own smoke riding around the Town square.