yznvegas, vanila gorilla

Thanks for the advice on breaking in a new top end. I used a combination of what you guys said and some of what the shop owners who run vertex pistons said.

1. 5 minutes at idle. Let it cool till cold.

2. 15 minutes 0-1/4 throttle. Let it cool till cold.

3. Warm up, easy 15 minute ride around the back yard. 0-1/4 throttle. Let it cool till cold.

Toward the end of the ride i noticed it was running really nice and picking up off idle really well. I might do a 15-30 minute ride at 0-1/2 throttle tomarrow but it seems well broken in now. I can't wait to crank it wide open :)

Right on Moto, that is awesome to hear the top end is breaking in nice for you. I know how you feel, the hardest thing about doing a top end is resisting the temptation of not breaking it in correctly.

The heating and cooling cycles are critical to break in. Don't ever let anyone tell you that you are too anal about breaking the piston in. Those same people are the ones who lock the piston up a couple of days after the rebuild.


By the way, make sure you make that 1/2 throttle run tomorrow. After that you should be good to go, just don't hold it wide open for long periods of time until you get about 1-2 tanks of gas through the new engine.

Thats what i was planning. I get to do this all over again when i rebuild my friends KX 125 later this week.

good to hear it mad man, gald i was able to help!

Finished the break in this morning. I just took it for a quick wide open up the road. It's a little gurglely off idle but thats because its about 80 today. It runs excellent besides that though. I dont think my neighbors like me anymore though. Oh well, i didnt like them anyway :)

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