New engine break-in help

[sportsfinat]

well ive heard about a million different ways to break in a rebuilt engine and they are almost all different. I am finishing my 350x and i bored .50 over and put new valves in. also threw in a 10 1/4:1 piston and new cobra. anyways, im just seeing if i can get some input on what would be the best way to break in the new engine right b/c i would rather not spend another 350+ bucks because i did it wrong. thanks in advance for the advice.

[jeffatc250r]

And your prob going to get a million different opinions on here also. My 2 cents is this, even at a fast idle of 1000rpm, think about it a thousand times a minute the piston moves up and down. If its gonna fail its going to happen pretty quickly if there is something mechanically wrong. I take it easy the first 20 mins as a mental reassurance and then hammer down.

[3wheelmecca]

I would run 50:1 premix, it seats the rings well, Ive done it in all my trikes, dirtbikes, as well as big cc streetbikes (including an X) and it set up great. Put in cheap oil, get your trike hot, and drop the oil. the cheaper oils have a detergent quality in them. then put in good oil, run 50:1 for about a day of light to moderate riding, going through powerband, but not reefing on it and riding it hard. sounds like overkill, but will increase the longevity of your engine. I would also run nothing but premium 91 octane fuel in it, the engine will really wake up and appreciate it.

[beets442]

Like jeff says there are a lot of different ways.
I take it easy the first few hours, run it up and down and then after that.....run her. + I make sure to change the oil after 5 hours and then 20hrs....Beets