gs550 Carb rebuild problems

[UWBernie]

Looking for a little help, I recently pulled the carbs inn my bike, bought a non runner got it to fire and mostly idle, although only when cold and without choke.

Upon inspection of the jets and needle it appears they are 650 carbs in a 550. no wonder it wasn't working well. Right now I'm planning on rejetting to get as many components inside the carb bodies to 550 spec. I've seen recommendations to stick to the canadian spec as close as possible, as the emissions in the us were thought to lower performance. Anyway here are my questions:

Is there a good source for GS550 needle jets and jet needles? I cant find them anywhere online.

or Will my bike run alright if I use the 650 needle jets and jet needles with the proper 550 jets?

If it helps my bike is a 81 GS550L with stock exhaust and a K&N filter in the stock Air box - minus the cover, mine didn't come with one so i fabricated vented one.

Any other idea? Thanks for any help

[BassCliff]

Greetings and Salutations!!

Hi Mr. UWBernie,

Any change to intake or exhaust will require jetting changes. The chart on my website may have the stock specs for your carbs. You'll also find a list with most of our favorite vendors in your "mega-welcome".

Let me dump a TON of information on you and share some GS lovin'.

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If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Cleanup Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. This is what NOT to do: Top 10 Newbie Mistakes. Now let me roll out the welcome mat for you...



Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

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Thank you for your indulgence,

BassCliff

[UWBernie]

Thanks

Thanks,

I've been lurking on the forums for a while now to see if I could find the solution to my problem. I've already replaced the intake o rings and have the set of o rings ready for the carb rebuild. I'm expecting I'll need to bump the jet sizes from stock due to the K&N but your website has been an amazing resource.

I guess I'm really interested in finding out if anyone has ever run different needle jets and needles on a GS550. I bought a set of "GS550" carbs off ebay that had a 550 kit installed in a set of 650 carbs (used your site to ID the ebay carbs)so I have for the meanwhile 2 sets of GS650 carbs one with 650 jets and one with 550 jets.

[Steve]

The 550 and 650 use the same basic carbs, only the jetting is different.

Stock jetting for your Canadian 550 is as follows:
main jet: 92.5
pilot fuel jet: 40
pilot air jet: 120
jet needle: 5f42-3
needle jet: x-6

jetting for the US-spec 650 is as follows:
main jet: 110
pilot fuel jet: 42.5
pilot air jet: 160
jet needle: 5c-45
needle jet: y-7

.

[UWBernie]

Thanks for the specs, I've been using those and have found the Jet needles have been discontinued every place I look. know anywhere i might pick some up?

If not I'm going to try getting the stock main, pilot, and air jets and a size larger and give it a shot with the 650 jet needles and needle jets.