Hi there Dave i just got a Ys .63 in the mail im so excited hehehehehe but i don't know what the small grub screw in the same packet as the check valve is for please explain

It's to hold a wire extension in the end of the HS needle if you need it.

thanks for the info another q is how much cooling air does the motor need when cowled its going to go in VMAR PC 9 and the ill chop the bottom of the cowl so the Rocker covers are in teh air stream. The inlet is scale and is quite small how many Sq cm do you reckon? and i got a 12*6 is that ok for break in and runnig ? i'm thinking 13*6 when its all going well?

Since I can't see your cowl, I can't pass judgment on your cooling setup. Take some photos and send them to me at

[email protected]

The 12x6 should be fine.