top end break in?????

[p-razzle]

Hey guys i just recently rebuilt the top end on my '01 kx250. Im talking brand new OEM cylinder, head and piston. Any suggestions on breakin in? Ive read some threads on new top ends but most of them were just new rings/pistons and not head and cylinder as well. Ive rode it two times since and never taken it past half throttle at most. Rode it for about 10-15 minutes at a time going through the gears and then let it cool down. I did this about 3 times per each ride. Im wondering if thats enough? Im looking for any suggestions! I have yet to open her up and im looking forward to it cuz she feels like a dragster ready to open up but im too worried about damaging it after i just spent all the cash on fixing it up?

[MXtras]

I typically baby a new engine three or four thermal cycles then that's it. Usually about 1/2 tank of fuel.

If you have ridden it three or four 15-20 minute sesions at light throttle, letting it cool in between I think you are good to go.

Scott

[ninjamonkey_16]

i agree with mxtras, i rode mine for three or four 15 minute cycles, and let the engine cool for abou half an hour each time.

[MXtras]

I have known guys who would fire up a brand new bike or new engine, run it for a few minutes, give it the once over and call it ready. I can't say these guys ever had any more issues than normal using their break-in methods, but I can't bring myself to do that.

Scott

[dogger315]

I can't say these guys ever had any more issues than normal using their break-in methods

They may not have more issues, but I'm betting their bikes aren't making
optimum power.

A proper break-in is very important. This is the time when the rings will
take a "set" to the cylinder. If done properly (several light to moderate
heat cycles), the rings will provide a noticeably better seal and produce
more compression = more power. Why go through all the work then piss
it away by short changing the break-in?

Every engine builder, tuner or factory mechanic I know is adamant about
proper break-in. Some go as far as using special oil (Kawasaki actually
sells break-in oil), or heat strips to quantify peak temperatures.

I agree with the others here and I think the steps you have already taken
qualify as a adequate break-in. Now ride it like your hair's on fire.

dogger

[p-razzle]

thanx for the input fellas! I think next time i take my bike out ill rip it and hold on!