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GS-550 carb problems

03-23-2004, 05:11 PM
Hi, I have a 1978 Suzuki GS-550. I bought it, it hardly runs. Gas dumps out 2 of the carbs when the gas is on. I took the carbs off and looked inside and noticed one of the floats was missing parts of the float (looks like someone cut it apart) and there is no paint on the screews on the bottom of the carbs (what do those do anyway?)

my question is, where can I get a cheap rebuild kit for this? Where can I get a replacement float?

biggest question is how do I tune this thing? what do I do for base settings? how do I know if its getting better or worst?

What sounds like the problem if the gas just keeps pooring over? the float right?


03-23-2004, 05:30 PM
Gas is pouring out b/c of the broken float and the other float is sticking. The biggest thing is to take out the jets and make sure they are all clear, if not take a small piece of wire and run thru them. As for base setting the only external settings are the air screw and the idle screw so those are the only ones you will need to play with.

To find parts you will prolly have to order factory parts. I doubt any aftermarket companies make a rebuild kit for it. So go to your local bike shop or suzuki dealer and have them look up the parts for you.

03-23-2004, 06:02 PM
Alright thanks alot, Does anyone know what the base settings on my carbs should be?

03-23-2004, 06:43 PM
I went and looked a exploded view of your carb online, so I wouldn't give any bad info. I've rebuilt a lot of motorcycle carbs and the settings are less important than on a car carb like a Holley or similar. The three things I think you need to do are: 1) get it to stop spewing fuel - either your float is sticking/sinking or your float valve is not working. 2) Make sure all the circuit passages are clear. 3) Next set all 4 carbs with an equal number of turns for each circuit (I would start with 2 turns out for pilot circuit). Most problems arise to a clogged or partially cloged circuit(s); the very best way to clean a carb is without doubt in the highly caustic, agitating dip tank at a shop. One more thing, don't squirt yourself in the eye with carb cleaner it hurts.

03-23-2004, 06:53 PM
Okay thanks alot, where are the circut passages in this carb? also where did you find the view of the carb?


03-23-2004, 11:02 PM
Pretty tuff to see, but here's a link to it.
I didn't know your exact model either, but they look pretty much the same.
Passages: There are at least 2 maybe three circuits in the system (can't tell from the picture)- pilot, main, and perhaps choke. You need to make sure all these circuits are flowing. Each circuit three things: fuel (from the float bowl), air (the holes on the horn of the carb), and a path to the bore of the carb. The choke is one of two types - fuel enrichment type adds fuel to the engine when cold, or air block off (just a butterfly over the opening. If it's the butterfly type you just have to make sure it moves freely; if its the enrichment type, you need to clean the circuit like the other two which I'll describe here: Usually, you don't need to seperate the carbs from each other or remove the fuel lines. Turn the carbs float bowl up. Remove the float bowls. Remove the float pin(#10), float(#9), and valve(#14). This will give you access to the jets. There are two jets (brass). #23 is the pilot jet and #20 is the pilot needle; this is the pilot circuit- it feeds the bike at idle. The other is the main jet (#19), it is screwed into an emulsion tube (#18) that feeds the main needle #25 - this circut feeds the bike above (roughly) 2000rpm. Take both jets and the pilot needle out and spray carb cleaner (using the spray tube) through the circuit untill its totally clear. It should spray through all carbs the same way. Notice where the cleaner comes out and spray into each of those holes too. Make sure the jets themselves are clear too, and be careful not to lose the o-ring (#21) or spring (#22) off the pilot needle. Also don't bend the needle, it's delicate. If you screw it in too hard it will leave and indentation on the brass. If it already has an indentation use a toothbrush to sort of polish it gently until the needle looks uniformly colored (not shiny in one spot). You can't run the bike without the o-ring (it'll backfire a lot when you close the throttle), so don't try, order a new one. Put it back together and fire it up. Hope that helps

Bray Hill
04-10-2004, 02:51 AM
Don't use wire to clean the jets, it will scratch the inside of the jet, effectivly changing the jet size. Main jets can be had at most any motorcycle shop for 2-4$ each, pilot jet are for some reason only available through suzuki.
And spinktec is dead on. Though there where 2 different types of carbs that came on the 78 550's.

03-01-2010, 07:55 AM
Hi I have a 1980 GS 550 suzuki. I am having problems getting it to idle. The bike runs good but you need to keep on the throttle or it will die. What can i do to fix my idling problem?

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