Sanity check--idle mixture screws

[v00d00child]

Had a shop in a nearby town install my chain/sprox yesterday (too cheap to buy the $100 chain tool). The XX had been performing flawlessly since the hi alt rejet. The majority of the ride to the shop was super slab, but when I exited to a side street, she started stumbling and missing--WTFO??? Mid and high rpm seemed OK, just idle to say, 2500 rpm.

I had the idle mixture screws set a 2 turns out. Not sure why after 200 miles she started to act up.

Backing the screws out allows more air into the circuit and leans the mix out, right???

TIA

chad

[Guest]

Make sure all the vacuum hoses are routed correctly. Sounds like you misplaced the one to the tank petcock diaphragm. There are 2 little nipples there, and one has a hole and the other is sealed. Make sure you got your hose on the right one. This was supposed to be a totally non-sexual response, but it just came out that way :oops:

Seriously, that haunted me for a few days, especially when the bike warmed up well. My mixture screws are out 2 1/2 turns, no problem....once I had the vacuum hoses routed correctly.

Good luck

[Pete in PA]

And for the second part of your Q. Turning the screws out richens the mixture from idle till the needle takes over completely.

For all you who want to adjust your pilot screws but don't have a jet kit which gives you a tool. A .17 rimfire case works. Just dremel off a section right where the brass widens than squeeze it lightly to form a D shape to fit over the screw.

BTW I just turned my screws from 2 1/2 to 3 turns out to get rid of a stumble at 3500 rpm when the temp is around 40 F. Besides drilling my slides It's a stock bike.

[v00d00child]

Pete-

Thanks for the rimfire tip--adjusting the mixture sure on these bikes sure is a PITA. Was thinking about trying to round up 4 idle speed flexshafts & hard attaching them to each carb's mixture screw, but didn't know where I'd round up 4 "d" tool tips.

FWIW, I've learned that trying to tune your bike after oh, say, 5 or 6 "MY JAYHAWKS JUST PUT ON A CLINIC!!!" beers is a very, very, bad idea.

[v00d00child]

Pete-

While I'm at it, what exactly does drilling the slides do for the bike? I'm assuming it allows the vacuum slide to move more quickly.

(I know it's bad form to make 2 consecutive posts, but I just noticed I broke the 100 post barrier, and am really feeling the momentum)

[Pete in PA]

Your slides holes might be the correct size already. I had put in a Dynojet kit then removed it because of the lousy gas mileage. It included a drill bit to drill the slide holes bigger to 7/64"

This allows the slides to react quicker to vaccuum changes both opening and closing.

Some XX's came from the factory with the bigger holes already.

I have flawless carburation now with the slides drilled, pilots at 3 turns out and stock everything else. :grin:

Now it's time to wear out the Avons all the way and get the Z6's on.

[testrider]

And for the second part of your Q. Turning the screws out richens the mixture from idle till the needle takes over completely.

For all you who want to adjust your pilot screws but don't have a jet kit which gives you a tool. A .17 rimfire case works. Just dremel off a section right where the brass widens than squeeze it lightly to form a D shape to fit over the screw.

Do you mean a .22 rimfire? I'm not aware that there is a .17 rimfire?

I still can't picture what the mod looks like. Could you post a picture?

Thanks!

-Mike-

[Pete in PA]

Sorry still no digital camera. :cry:

For you gunny types there is a new rimfire on the block. It's the .17 Hornady magnum rimfire or 17 HMR. It is a .22 mag case necked down to a .17 caliber 17 grain :shock: bullet.

Just go to any range and you will find the cases all over the ground. It is VERY popular already.

The D pilot screws are about .20 caliber that's why I cut the neck halfway up for the tool.