Alltoys, I know for a fact you run the crap out of your 650. I have talked to you enough to know you like pushing it to the limit.

The "run it for a while, let it cool down, and then run it again" method is perfect for two strokes, but valueless on a four stroke. The break-in period on a two stroke is critical. Not so for a four stroke.

I think the "use your brain" method is the best for a four stroke. No continuous WOT for at least 100 kms but don't be scared to give it a quick WOT. Dangerous is right. If you don't give er during your break-in, your piston will form a ridge at the top of it's stroke. When you do tape it, your rings will slam into that ridge and POW!!! one dead 650. This is just my opinion, tempered by talking to very experienced mechanics. Take it any way you like.

 

I did the 10 hr brak in then put synthatic in it and haven't had a problem yet no smoke no oil usage.

 

Breakin is almost a witchcraft. There are so many different ways that have been recommended. That does not mean that the way you break in one engine is the right way to break in the other. There are so many combinations of ring hardness, ring design, cylinder hardness, piston clearance, and piston cooling ability that you sometimes destroy an engine if you break it in the same way as you would another. Most part of the motor do not really need special treatment for breakin, except round (spinning type) lifters and the cam they ride against. Those things are the reason thas some engine remanufacturers tell you to run at a fast idle, 2000rpm or so for 30 minutes. Our 650's don't have those, and we would probably be better off not following that kind of breakin procedure.

Here are two ring breakin basics:

1. The higher the cylinder pressure (they call it BMEP), the faster the break in. The highest BMEP occurs at the engine's peak torque RPM at full throttle. If there is not enough throttle, the window of opportunity of correct ring breakin may pass. Low throttle is very bad for some engines. This is why so many manufacturers have high throttle or full throttle breakin procedures.

2. Ring breakin causes extra ring, cylinder and piston heat. There is a greatly increased chance of piston melting or scuffing problems as a result of breaking in too fast or at too high of an RPM. Also this is exactly when varnsh forms, when you break in too fast and get the oil on the cylinder wall too hot. Varnish will cause the rings to stop seating preoperly and the motor is going to eventually have blowby and/or burn oil. Some engines do not heat enough to cause varnish even at full thottle. Therfore the best breakin procedutre for some engines is to break in at full throttle under a load that keeps them at a midrange RPM. However I have never seen one that recommends the high throttle at very high RPM. Any body that obtained a properly broken in engine while revving it to high RPM's either didn't do it much, got lucky, did it after the rings had pretty gone past their main seating stage. I have seen a few engines gall their pistons or seize as a result of breakin running too long at high RPMs during breakin.


You know what guys, the manual says "Do not exceed 1/2 throttle during the break-in period. If the vehicle is not used carefully during this period, you may end up with a broken down instead of a broekn in vehicle".

1/2 throttle doesn't seem like a smart breakin. The manual has some erroneous info in it written to cover kawi's fanny in the event of a legal dispute. I will gladly point them out if anyone is interested, since it is has a lot of legally protective, but incorrect advice.

What I don't actually know, is was that breakin statement written as more of a legal protection, and it would be better to break it in differently.

Maybe intermittent full throttle (but not high rpm's) is the best thing to tell people. Full throttle with brakes? Who knows.

I followed Dangerous' advice (just ride it, full throttle or not) to break mine in (but I was careful to keep from high RPMs). I did not do it because I felt the manual was wrong, but because I could not resist pushing the throttle. That could possibly be the best breakin advice. We really don't know yet for sure. I do honestly know that my 650 is not blowing by, not using oil, and not darkening the oil fast. So far it seems to have been broken in well, even though I used full throttle.

To bad we really don't have any data. One guy around here had a lot of blowby, I forgot his name. Maybe that guy varnished his cylinders at higher RPMS during ring seating, maybe it was something else.

 

Varnish forms only at low rpm and high heat. You will never see a 500 mile NASCAR engine come in for tear down with varnish on the cylinders or piston faces. In the old days, when all we had were cast rings and cast or menite blocks, break in had to be done slow and easy to avoid like metals wanting to become one again. We no longer have to worry about such things as we use chrome moly or better rings and hard cast cylinders. If you overrun a new engine, most likely you will simply over burnish the piston rings, which results in lower compression with less than optimum performance and or oil consumption.

If a modern day engine of any type,(built within the last 25 years) will not stand a full throttle run out of the box, it was junk to start with.

 

Howdy Gang,
I used to be into drag racing. When we built an engine, the first run was always the fastest for that engine. There was no break in period! My 650 was run hard from day one and a year & a half later is still running strong. I think that break in is in the eye of the beholder!!!!!

 

Sounds like a lot of different opinions. I guess I will just ride.

 

I would give it atleast 600 kms to break in. I had some issues because I though five hundred was good. This is the first bike that I really broke in proppery, the others I just got on it and went.... but I heard lots of stories about breaking twin motorcycles in so. I wish the next 650 I buy the factory could break it in for me.

 

I wanted to break it in according to the manual but I just couldn't help myself beating everyone in drag races ect. Engine running fine 1 1/2 yrs later