Guru porting oppinions (pics)

I purchased a 2010 250r full mod. I was doing a rebuild on the head, and noticed the porting around ihtake valves was grinded to a straight flow to valve dish. I know on previous year crf's have quite a bit of material around guide (not sure about 2010). To me quite a bit of metal and guide were removed. Is this something I should be concerned about. It was a full mod Loretta Lynns bike that placed in top 25. It rips for sure.

1368480921175.jpg

1368480946177.jpg

i prefer to keep as much guide as i can theres no flow gain to speak of in grinding it away but i have seen a lot of heads done that way .

i prefer to keep as much guide as i can theres no flow gain to speak of in grinding it away but i have seen a lot of heads done that way .

Thanks for your reply. When I replace the guides should I grind them flush again or would it be safe to leave them without the cylinder area support not being there?

Edited by iMOTO189

Thanks for your reply. When I replace the guides should I grind them flush again or would it be safe to leave them without the cylinder area support not being there?

Don't grind flush it's a waste of effort.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now