yz 250 break in methods

[dman16]

what are methods of breaking in a new top end and which are ones i should not try?

[Ford]

Hmmm,

I would say no more than 1/4 or 1/3 throttle for the first run through the gears riding it like that for about 15 minutes. Then no more than 1/2 throttle through the gears again running it like that for another 15 minutes. A long dirt road isusually good for this. Then after you have rode it for about 30 minutes like that then run it in the power band up and down the gears for about 10 minutes (1/2 to 3/4 throttle). Then check it over to make sure it sounds good and nothing is leaking orother wise then hammer time it is broken in baby, because anymore riding soft like that and it will carbon up on you, lol! This is what i have done and i have never had a problem.
The one thing you might notice is after you have redone the top end you usually notice the difference right away in terms of how good it sounds, how good it feels and how good it runs. It will feel really tight, especially if you havent redone the topend for a long time. DONT hammer it hard until you have slowly stepped it up like i recommended above. This was told to me by a race mechanic for Yamaha, it only takes about 30 minutes in total to break in a new top end or even a new bike for that matter but with a new bike then you would change the gear oil after a couple of hours, etc. Anyhow i hope this helps!

Cheers,

Ford