carb air screws question

[Anonymous]

Working on the carbs (1980 GS550L), and I've been having TONS of fun with the air screws (stupid red loctite ](*,) ). Managed to get two out so far by soaking them in carb cleaner, but I think I'm going to have to take a torch to the others.

Anyway, I'm pretty sure the air screws have never been out before. When I pulled the two out, all they had on them was a little o-ring. Based on the pics in the carb rebuild guide, there should also be a washer and spring. Seems a little weird that mine don't have them. Is it ok to be missing the washer and spring? Can I get away with putting them back together without the washer and spring? or is it going to mess things up?

Thanks a ton.

--Tyler

[Jay Swan]

1980 GS550L Missing Carb springs & washers

Tyler,
I have rebuilt the carbs on a 1980 GS550 E (chain drive) and the O-rings, washers and springs were in all four carb pilot jet assemblys. I would think they are the same carbs on you bike too. I cant believe that 2 carbs would have them and 2 not. Anyway, if you go back to the forum and search for "pilot jets", you will find a wealth of info and maybe the parts info. There are quite a few guys who know where to order this stuff. I think there is a place in Canada or in the northern states that have the springs, washers and o -rings that you need. How about it guys? Can you help out Tyler?
I hope you get the other pilot screws out ok.

Jay

[Anonymous]

Thanks for the help Jay.

On my carbs, it's not that two have the spring and washer and that two don't, but rather that I've only been able to get two out so far, and both of those are missing the spring and washer. I can only assume that the other two are the same. Hopefully I'll be able to let you know tomorrow.

I assume when I say "air screw" and you say "pilot jet", we're talking about the same thing. I'm going by the labels on the pictures in the carb rebuild section.

--Tyler

[KrazyKarl02]

What kind of carbs are these?

The answer to your last question depend on what kind of carbs came on your 550, are they vacuum or mechanical?? Does the top have a vacuum diaphram (vacuum carbs) Or is there a cylindrical slider (mechanical carbs)??

Keep in mind I have never messed with a 550, just 750's, 850's and 1000's but anyways a vacuum carb has only one external adjustment (excluding the synching screw on the linkage) , this being the idle screw, or air screw, or pilot screw it controls the mixture at idle, and no where else!
A mechanical carb has the above mentioned screw, plus one on the side, which I do not fully understand, anyone who understands that screw pleases insert their 2 since.

At any rate if it is a vacuum carb I would think it should have the spring, washer o-ring setup

[Anonymous]

That is kind of odd. My bikes were sent to Canada first so neither of them had loctite in them. Both of them did have the washers, orings, and springs except for a missing washer lost by somebody other than me. Missing washers don't appear to be a problem in my mind since the springs have fairly flat ends. Have you checked the BikeBandit fiche to see if those parts are supposed to be in there?

Steve

[SqDancerLynn1]

Try heating them up with a hair dryer or boiling hot water

[KEITH KRAUSE]

OneStaple, they are called mixture screws, not air screws. The fuel and air have already joined by the time they reach the mixture screw. So adjusting it in or out, regulates the amount of mixture, not just the air or fuel. The spring/washer set up is designed to keep the screw from moving due to vibration.(though the factory sealant does a good job ) I've never seen an undisturbed screw missing these. I think your screws have been moved at some time. Anyway, the o-ring seals the screw, which is the most important. If you cannot find replacements springs/washers, they are not necessary. To avoid having them move on you, put a little light duty thread lock on them or a dab of silicone on top the head after you've set them. It would still be best to find the springs since the screws are meant to be readily adjustable if you go into higher elevations, etc.
Sometimes the springs are hard to see because they may sit way down in the hole. Are you sure they are'nt in there?

[Anonymous]

KrazyKarl - they're the CV carbs typical on carbs after 1980.

Steve - I checked bikebandit, but it doens't really show any of this part of the carb (doesn't show the screw, o-ring, washer, or spring, from what I can see). Perhaps because they don't want you to remove them? Otherwise, the schematic is identical to what I have, from what I can see.

Keith - I guess it's possible that these screws were removed before and then loctite reapplied. The heads on them are messed up somewhat, but I just attributed that to someone trying (unsuccesfully) to remove them. Knowing that the spring and washer should be there, I think I'll look to replace them, and then perhaps use some blue loctite (a much weaker version than the red I have on there, made just to hold it in place).

Thanks a bunch guys.

--Tyler

[Jay Swan]

Tyler,
My mistake, they are called mixture screws. By the way, when I had dissasembled the carbs on my 80' GS550, the mixture screws were covered by a soft metal plug that had to be drilled out. My guess is that if the plugs are missing, then one of the previous owners had at least pulled them out and left out the parts or missplaced them. It isd easy to do they are so dang small.
Do you have the other 2 screws out yet?

Jay

[first timer]

if you want the spring and washer assembly you will have to buy 4 rebuild kits off ebay or where ever, they will give you a new needle screw, spring, washer and oring.


ryan

[Anonymous]

I managed to finally get the other two screws out after a lot of fussing and yelling at the carbs. The final count was that all four had the o-rings, one had a washer, and none of them had springs. Kinda weird. Anyway, I did have rebuild kits, so I stuck the spring, washer, and o-rings in all of them.

Any comments on how to adjust them properly? I put them back where they were when I pulled them out, but if someone else already had them out, they could very well be messed up. Three of them were just under two turns out, and the last was three turns out. Go for getting the highest idle?

Thanks.

--Tyler

[KEITH KRAUSE]

That's what I would do. Be sure your air filter is reasonably clean. Put the bike on the centerstand and warm it up first. It's easiest to hear the rpm's rise if you evenly adjust 2 screws at a time. I would start with them 2 turns out. Move 2 screws in or out 1/2 turn and do what the rpm's tell you. After you get all 4 set, re-set the idle with your idle screw knob. Just for our knowledge, let us know how far out they end up being.