KDXRIDER.NET

Just curious. The parts diagrams don't show one either. Seems kind of odd.

not on the pwks fitted to older bikes like the kdx etc..I think there is on the modern ones fitted to ktms /husabergs etc...I wrap a small piece of ptf tape ( used on boiler/gas fittings) around mine just to make it seal better..likewise on the tickover screw..i know on a 4 stoke fuel screw theres a small o ring & washer.

Yeah, I was just double checking. Thanks wrecker. I have an o ring and washer ill fit to see if it helps or hurts.

How come you have decided to fit an o-ring & washer to the kdx pwk?? have you purchaced a new air screw by any chance??

Nope. Same ol airscrew. I had a yamaha raptor for my kid that I just couldn't get running right down low. I rebuilt the carb, checked compression, cleaned filters, etc. one day I noticed it had no o-ring or washer on the airscrew. I added them, and whatta you know, it cleaned up the saggy spot on the low end. What I think happens is wear in the bore more than anything, and an o ring might seal it better. My Kdx, though, needs either a leaner main(155 current) or a step leaner needle. I'm just going through the entire bike fixing problems the previous owner neglected, and I thought of that airscrew o ring . You know how it is, try anything to achieve performance perfection lol.

since wrapping a little ptf tape around my air screw & tickover screw my jetting has been more easy to set up/ tune...I think air can & will get sucked in when the bike is running making it difficult sometimes to get things spot on...I first noticed a while ago when I came back from a dusty ride that I had damp patches around these screws where fuel could clearly be seen absorbed by the dust ...since applying the tape theres no more damp signs & the bike idles perfectly too.

Absolutely! Most threads aren't completely airtight, especially when there's an air pump on the other side of the screw. That's why, like you, I feel that airtight airscrew is the way to go. ANY small leak in that area has to be bad, and that area affects the throttle range that is giving me trouble.

I also use a bit of teflon tape around the screw threads on the air screw, but behind it is just the spring. Washer an o-ring should be fine as long as you don't lose any adjustment range.

Just got in from installing my carb again with o ring and it did indeed seem to help. Sadly, my bowl gasket started leaking, so until I fix that its untested.