high revving a 440

[400exJOE]

well this weekend i hope to breakin my 440. I know I shouldn't go over 1/2 throttle for 10hrs., but my question is, once it is broken in, will I be doing a lot of harm revving it out like I did b4 the 440? I just like to play race and stuff, but I don't want to be worrying that I am going to kill my engine from riding fast and hard sometimes. Thanks y'all ;)

Why is it that you can't go over 1/2 throttle for 10 hours. After my 416 kit w/cam was put in,,I took it for 2 - 15 minute rides at no more than 1/2 throttle then I took it for a 20 or 25 minute ride at no more than 3/4 throttle next trip out the hammer was put down and she's running really good. I also let the motor cool all the way down between these rides..

[oynot400]

Once you get it broke in you shouldn't have a problem reving it out. Heck I raced flat track, with is alot of WOT running and mine is still together.
I wouldn't wait 10 hours to go over 1/2 throttle. There is a post talking about break in proceedures.
Run it at low idle for 5 minutes for the first time and let it cool completely down. Do this a couple more times giving it a little more throttle each time, also vary the rpm's. Then give it a ride again varing the rpms I wouldn't go over 1/2 throttle on the first ride. Then each ride after that push the engine a little more. I think the key is to let it cool completely downt he first couple of times to get the rings and valves to seat.

[400exJOE]

thanks guys. I was just concerned that it would be bad for my motor to ride it as hard as b4. Also, my clymer manual said 10hrs. at no more than 1/2 throttle and another 5hrs. at no more than 3/4 throttle.