1983 GS550L carb rebuild, where do i start?

[VapeMaster]

Hi guys, i'm a newbie to riding and motorcycles in general but I recently got my hands on a 83 GS550L that was running a year ago. The PO was my good friend and has had some extensive work done on the bike, including brakes, new fork and a new starter and gave it to me for $500. All is well and good except that she doesn't quite run. two main issues:

1) I can get it to start somewhat reliably after doing a thorough carb clean (full dismantle just with spray, no dip) but only with the choke about 2/3 in and periodically the idle flies up and i have to control it with choke. if i give it too much gas it bogs out and dies and if i put the choke to 1/2 or less it dies all together. from what i've read on this awesome forum I need to take it back apart order new orings from cycleorings and dip everything metal. I'm guessing I have a vaccum leak somewhere and that's making it run extra rich which i'm compensating for with the choke? I just want to make sure i'm getting the right orings i believe it's a BS series carb , it's that weir siamesed thing though where each diaphragm has two needles on it. The carb page is really helpful but it doesn't show me how to work with the "siamesed" carbs and I wondered if anybody has any experience with these guys that they want to share with me before I start ordering parts. Also the plungers look a little worn and I had to fix a needle that was loose when i first dismantled it and it looks like its missing a tiny little washer. i think it works fine now but it's definatly a little scuffed at the junction of the plunger and needle. does anybody know where i could by a full rebuild kit for that carb for a resonable (ie <$75) price or am I dreaming.

2) (this is a little off the carb topic but i thought I'd consolidate posts) the PO said that when he first had the bike it was running well but he noticed two wires poking out of the stator case. when he had a shop do some work he asked them to tuck them back in. those fools must have grounded something out because after that he said that the battery would die after 45min of riding. any guesses on what those two wires were and how i can un ground them?

thanks for any help you guys can give me, the more info the better. like I said i'm super new to this and all i know is what i read so any tips and tricks you guys know would be awesome.

Can't wait to feel this beauty GS purring between my legs! (that's what she said...?)

[Redman]

Welcome to GSR.

Start with two things:
1) the Carb Cleaning series, can find a link back on GSR home page.
(not the forumn, but the GSR Homepage.). THe carb ceaning series is a series of links that have a total of something like 150 steps each with a photo. Is a complete dissasembly of carbs, and carb "dip" in carb cleaner solution.

2) Search for Robert Bar cycleoring website for replacement intake boot o-rings and bolt set, and for carb o-ring set.


Also, post the question about the stator related wires in the electrical section. IT will get difficult for you and others to follow responces to two different topics. (I have a suspect what those wires are.) Include in your post the color of the wires. And tell us if you have a volt meter (you will want to have one).

Dave
.


>>>later note

http://www.thegsresources.com/gs_carbrebuild.htm

here is link to carb cleaning series.


>>and further yet note
Oh.. quess I am not faimilar with the siameese carbs that you mention.

.

[Redman]

Oh...

[VapeMaster]

@Redman

Will do on the stator question.

I saw those carb cleaning series (which is awesome you guys are lifesavers) and i followed it as best i can right now, I'm not quite settled down and will be moving around a bit. But i want to make sure i was ordering the right orings form cycleorings.com because these siamesed carbs seem to be a bit different than most of the carbs people discuss in the forum and are different than the carb pictured in the carb series. I believe i want the BS sereis and the intake boot orings to match from cycleorings, should i just contact Robert Barr directly about that?

[VapeMaster]

thanks for the diagram, it looks a little more complete than the one in my Clymer manual. it looks like i'm missing washer #25 on that busted plunger. also are there mixture screws on these carbs and if so which # would they be on that diagram?

[Big T]

thanks for the diagram, it looks a little more complete than the one in my Clymer manual. it looks like i'm missing washer #25 on that busted plunger. also are there mixture screws on these carbs and if so which # would they be on that diagram?

The mixture screws don't show up because they are "sealed"

Unseal them

[VapeMaster]

i would love to, any suggestions on where they are and how to unseal them?

[cowboyup3371]

A "thorough" carb cleaning does not mean spraying it down. Take everything apart again and dip them for 24 hours each. I would also take off the stator cover and look at your wiring. Be sure you have an impact driver to get those screws off.

[mike-s]

Wow, ive never actually seen someone who has these, i've seen a photo of them assembled and on a bike, but someone actually has one? There's a first for me.

As to the parts, 28, 29 (circled in green as they are the pilot & main jet), 31 (dark blue/ emulsion tube) and 45 (pilot air jet, i missed circling it) need to be removed and thoroughly cleaned up if they haven't already at a minimum. as others have said it sounds like the idle pathway is clogged and needs to be cleaned out, this is located under an aluminium cap on the top/front of the carb (what looks like them is circled in red). My take on this carb design is they share the functionality of some of the low end circuits, i.e. parts 37-41(circled in brown).

What you are looking for under the cap (which you don't need to re-attach after doing the work as it's supposedly there to stop you fiddling on US models, NO bikes sent to other markets have these). There is likely going to be a threaded needle, washer and o-ring underneath that cap if i have interpreted the diagram correctly.

From what you've told us it seems the choke (actually enrichment) circuit seems to be able to draw adequate fuel to work, so leave it alone for the moment. Focus on the idle circuit.

If you don't have access to sufficient dip to work on the entire carb (if you dip you need to remove EVERY rubber component, or replace it after the dipping as it will be destroyed by the treatment), then you can do what i did, which is to get an aerosol can of carb cleaner and lightly spray a little down the idle needle hole, make sure that it can drip through to the main venturi (the big horizontal hole with the butterflies in them).

Once this is done, put it on a clean surface (so you can see how much gunk comes out) and spray a little carb cleaner in the passageways you can see in the needle jet (i find the easiest way to do this is to put a finger over the bleed holes in the venturi and then fill the idle needle jet region up with carb cleaner out of the can (spray lightly when doing this, otherwise you'll be wearing the cleaner) and then move the carb about until the cleaner starts going down the passageways leading off into the carb towards the fuel bowl.

Now flip the carb upside-down, and (again lightly) spray a little carb cleaner in the pilot fuel jet hole in the carb bowl (i can't tell from the pics, but it will be the smaller brass screw with a hole in the middle). Once this has soaked for a while, then get a long piece of 2-4 lb fishing line and poke it down the pilot jet hole as far as you can and jiggle it about. Then do the same from the needle side.

When you have done this, then using the tube attachment on carb cleaner, degreaser, wd40 or whatever and put the end of the tube in the pilot jet hole, try and seal it with fingertips on one hand as best you can and spray it through from one side and see if it works its way through. In addition to doing this, you need to do the same with the pilot air jet hole too.

i also have a can of compressed air (i don't have continual access to a compressor), which is extremely handy with doing this kind of thing as you can alternate between all of these three passageways with these different methods i have suggested and eventually you'll get a nice big stream of cleaner shooting through inside the carb.

I'm sorry, pictures speak 1000 words, but i haven't got pics of me doing this procedure unfortunately as my hands were full with just doing it .

[JEEPRUSTY]

It is normal for the bike to rev high on choke.
Sorry it is true.

Check your carb joints an o-rings
dump some sea foam into it and ride.
The idles screw sill cealn out and the only thing at that place is o-rings.
Do not tear into the carbs just to replace these.

[mike-s]

That may be true JR, but he can ONLY get the bike running on the choke. Once it's warmed up enough to run it should do without the choke provided there is enough throttle. As it is it cannot run on the throttle for some reason, and as the bike hasn't run for a long time there is a good chance there's a clog somewhere.

[VapeMaster]

thanks for all the suggestions guys! i'm going to order the orings but in the mean time just try a real thourough cleaning and dump some seafoam in afterwards. i'll keep you all posted!

[VapeMaster]

sorry to revive an old thread, but just an update:

toothbrush + carb spray + WD40 + seafoam in gas tank = running bike!

now i just need to figure out the charging system when I get back from a visit to the family.

One thing I ran into during the carb cleaning was the mixture/pilot air screws. I found them at long last even though they are mysteriously unlabeled on all diagrams but only one was movable. I counted turns in (~3.5) and then unscrewed it, sprayed and tightened to where I found it. But then when I went to do the same to the others i found them all frozen in place with nearly commpletely stripped heads. Following this forums advice i sprayed them full of WD40 and let it soak while I went out and got an impact driver. I set it for reverse and WHAK! but nothing budged! I wound up breaking the tip off the flat head bit. Either they're screwed all the way in by some foolish mechanic (I assume that wouldn't let the bike run though..) or they applied some locktite to those guys and I'm powerless to tune 3/4 cylinders. Any suggestions from the all knowledgeable GS crowd?