[ha954rr]

I live in Portugal and I have an european 2007 CRF 450X. The only changes that I made were an Akrapovic Slip On, #150 jet, a Polisport MMX headlight and a Trailtech Vapor.

Considering the information from the Vapor the max RPM is about 10.300 RPM. With the original slip on it was enough, but with the Akrapovic is seems that the limiter come too soon.

Regarding the airbox mod I have some doubts because I usually use during the winter, so I need to cross some water courses I some water could come to the air box, so I keep it closed. I did the same on my previous WR426 and I did not feel a lack of power.

Does any anyone feel the same? Or recommend some other mods.

I saw the JD kits but it’s difficult to obtain it here in Portugal.

[Ernie Pezz]

Running the Akrapovic pipe with a 150 main sounds like you'd be a little lean. Did you adjust the needle or fuel screw at all? I would recommend the airbox mods with the proper jetting. You don't want to make a lean condition worse. I'd PM Ken, the owner of this site, to see if he can ship the JD kit to Portugal. Or if you have access to Honda parts, you can go to the jetting forum on this site and use the needle and jets that some of the REAL tuners have used.

[[email protected]]

I'd PM Ken, the owner of this site, to see if he can ship the JD kit to Portugal.

I agree-
http://www.crfsonly.com/catalog/product ... ts_id/1093?
Or, just drop your needle clip DOWN (raising the needle) to the next to last clip space add a 165 main jet ,and simultaneosly do this :
http://crfsonly.com/howto/450x/airbox/c ... airbox.php
Do not do the airbox mod without doing one of these two things with your jetting.We've never had anyone report a problem with the airbox modification,and we ride in a lot of wet,nasty stuff too and do cross streams.
If the European 07's are like ours you can't adjust the needle clip,and you need a needle and needle holder for an 02-07 CRF450R, OR A 2005-2006 450X.
If you have a smog device on the right side of your engine install one of these :
http://www.crfsonly.com/catalog/product ... cts_id/858
Doug