Has anyone actually tried this? High Velocity Intake Porting

[DF400ex]

I know that this has been posted here before, but has anyone else tried the high velocity intake porting and engine break in tips as stated at http://mototuneusa.com ?
I was thinking about trying the smaller intake ports. Just wondering if anyone else has had success with it. Let me know what you think.

I know that people think that smaller ports making more hp is absurd. And to break in your piston and rings you run it flat out?

The guy makes good arguments and I can attest to the break in tips. When I broke in my new piston and rings I did what he said and it's been going strong for over a year now.

[400exrider707]

I always break my motors in this way. My father who used to race snowmobiles on the pro level (vermont state champ in 79) said every sled he would break in, he would go out to a lake, start it up and then run it wide open for as long as he could. (there is a theory behind this, I've posted before...) as far as the velocity porting, I believe there was a guy on the ORG who tried this, but I dont remember hearing much about it myself.

[DF400ex]

Cool. That's How I break in my motors and it's worked great. I just don't wanna start the porting till I know someone's done it before successfully.

Originally posted by 400exrider707
I always break my motors in this way. My father who used to race snowmobiles on the pro level (vermont state champ in 79) said every sled he would break in, he would go out to a lake, start it up and then run it wide open for as long as he could. (there is a theory behind this, I've posted before...) as far as the velocity porting, I believe there was a guy on the ORG who tried this, but I dont remember hearing much about it myself.


ok if you let it warm up first ok but if not he messed the rings up everytime