idle mix screws

[yamtom]

Hi,

I am wondering if any of you have had problems with idle mix screws loosening or moving due to vibration in the late model carbs. Ive got new ones in, and they seem very easy to move, wondering if they ought to be loctited, or maybe sealed with seal all once Ive got everything perfected.

[psycoreefer]

Did you put the spring, washer, and o-ring in there as well?

I've never had trouble with mine moving, I've never seen a post where someone found theirs moved. So I would say, no, its not a problem.

I wouldn't put any kind of sealer on them, I'd be afraid it might plug up the passage, or make it really hard to remove or adjust the screws later.

[DGXSER]

I agree, you must be missing the spring, the washer, or the rubber o-ring or all of the above if it is moving on you. Either that or your jetted wrong and have it loosened out more than 5-6 turns such that the spring is fully released.

[81xsproject]

NOOOOOOOO!!!!!!!!!!!! Don't locktite them! You will never get them out or turn them again. I use a smidgen of Anti-seize on them. I agree with the others that IF it were possible for them to turn on their own (which I don't think is possible due to the extremely fine pitch threads) it would be time to replace the o-rings.

[yamtom]

o rings etc

Ok guys, the parts are new, all springs washer and o ring is in place , I was just wondering if that vibration would be a potential problem. I will do the anti seize on them, they sure move nicely now, unlike the old ones. My son in law was worried about those screws backing out from vibration. We had an awful time with getting the old ones out, so I dont want a repeat of that in a couple years. You guys are so fast , wow. It never ceases to amaze me how quickly youz answer. Thanks a lot. The bike now idles beautifully with the clean and new carb parts. I ended up doing a triple clean on them, or more, ,,,,,,,,,,,,,,,,,,,, Thanks again.

[jmnjrpa]

you can

stretch the springs a bit to apply additional pressure but it sounds as if something is wrong. Like the spring is not compressing due to wrong idle screws. Some PO's have changed out carbs and the screws may not be right. GOOD pics would help determine the model carbs you have.

[dbeardslee]

I did a set of late model carbs last year and got the same kind of symptom - properly assembled but not much spring tension. Those were in the 5-6 turns out range, and turning the screws out that far relieved a lot of spring tension, so they felt kind of loose. I had the same bike over here last weekend, with the same mixture screws installed, and they seemed much stiffer to turn - not at all loose. So what happened to them? I think two things explain it. First they've had seven or eight months for the carbs to get hot, and for the geometry of the o-ring to change (they get kind of smashed down, and fit more tightly). Second we changed the jetting, and with a bump to the mains I only had to back them out in the 1-2 turn range, so they've got about 1.5mm more spring tension (.5mm pitch X 3 turns = 1.5mm). To me, when you start getting out in that 5-6 turn range it's an indication that you're not jetted quite fat enough - either on the mains (which will affect idle and low speed operation) or on the pilots. My question for Tom is, how many turns out are you on your's?

[yamtom]

springs

Hi Guys,

I definitly have the late model carbs, Ive seen many pix of both, and actually have an old style set here to compare them with.

I am trying to build Johns manometer but cant find the detailed file that he made. If you have the link, please send it John.

My idle mix screws are one and a quarter turns out right now. Ive played with them a bit, and the stock setting seems about right . Ive adjusted them out to about two, and it barely makes a difference.

My kits came from Georgefix, I carefully checked all of the parts against the originals, they are the same in numbers holes and threads orings etc.
I have the bike idling on the stand, it takes a quarter throttle nicely, very nicely I might add. Ive had trouble with the fan cord so I havnt done more towards synching the carbs for fear of overheat, its eighty degrees here today, wow, twenty degrees warmer than normal.

I dont actually have any sense that the springs are too loose at all, they are the same length as the old ones. It was just a potential concern that made me ask about the loctite, haha, sorry to have set your concerns off so much.

With any luck I might have it off the stand and running thru the gears by tomorrow. I sure could use the manometer file of Johns though.

[DGXSER]

Yep, sounds like you are right on the money where you want to be. about 1-1/2 to 2 turns out should have it purring like a kitten on fresh carb kits and stock intake and exhaust. I think you will find she runs VERY nicely through the rpms too.

From what your telling us, your son is a bigger worry wart than me. And that is saying something. You should have zero issue with those screws backing out.