I have answered this question in a PM to you, here it is again just in case you missed it because of the different time zones that we all live in.

Hi 450X

This XT motor needs extra volumes of air to perform, the motor is very restrited on the intake side & responds to the air box being modified to enable extra air flow.

There is a small gain in HP when removing the snorkel, but would recommend a stage 1 & 2 DNA filters with a fuel mod which will give you around a 12% hp & toruqe gain.

Some info for you to read.

http://www.xt660.com/showthread.php?t=4509

http://www.xt660.com/showthread.php?t=3215

Cheers
Kev

I've removed the snorkel. Uning stock cans. I find the sound of the engine very "strange" in low and mid RPM. Kind of ticking sound. Must be some resonance sound. On higher RPMs it sounds great :)

I will reinstall the snorkel and turn back the CO level on Sunday. Cause the XTX will be left at Yamaha Center for it's first 1000km service :)

I'm not sure what they like about removed snorkel and altered injection parameters...

[quote=_Rick_;104754]I've removed the snorkel. Uning stock cans. I find the sound of the engine very "strange" in low and mid RPM. Kind of ticking sound. Must be some resonance sound. On higher RPMs it sounds great :)

I will reinstall the snorkel and turn back the CO level on Sunday. Cause the XTX will be left at Yamaha Center for it's first 1000km service :)

I'm not sure what they like about removed snorkel and altered injection parameters.

The strange sound is from the AIS induction pipe, block off the AIS pipe & it will make a difference.