Jet needle spring issues

[Guest]

I was looking to adjust or shim my jet needle and I have noticed that my springs (the springs on the needle itself) are considerably different in sizes and gauge on my 81 gs650g. Cylinders 1 and 3 have the same shorter fatter ones and 2 and 4 have longer lighter gauge ones. Is the normal? Also 2 thru 4 say 5c45 on the needles and number 1 says Y86.

[tom203]

Should all be 5c45 with Y-7, see this chart

http://members.dslextreme.com/users/bikecliff/images/carbspec_float_height.html#A01

[dackcommabig]

thank you tom, why does it have 2 numbers? Is one for the spring?

[tom203]

The terminology gets confusing..... The Y-7 is the needle jet (really a tube with holes) that the jet needle slides up and down in... See pic

are you refering to the spring that holds the vacuum slide down?

[dackcommabig]

There is a spring under the circlip which sets needle height (mine are non adjustable) on the jet needle itself. Tried to stretch the shorter springs but didn't notice much of a difference. I shimmed the needle and that helped overall performance but it is still bogging at 5-6k. Should I look into bigger main jets?

[tom203]

What do you have for intake.. Stock airbox setup? Pods?
are your main jets all identical, 110 mikuni? Do all the needles stick out the same distance from vacuum pistons?
At 5 to 6k rpm under load, you need lots of fuel- check petcock for decent fuel delivery, maybe try running it on "PR" spot

[JTGS850GL]

There is a spring under the circlip which sets needle height (mine are non adjustable) on the jet needle itself. Tried to stretch the shorter springs but didn't notice much of a difference. I shimmed the needle and that helped overall performance but it is still bogging at 5-6k. Should I look into bigger main jets?

The spring under the circlip does nothing to set needle height. The spacer above the needle is what sets the needle height on a stock carb.

As for the original post, it seems that some PO must have swapped out different carbs in the rack from different bikes. As stated above, you should have the same needle and needle jets in all 4 carbs and the correct ones are 5C45 needle and a Y-7 needle jet. At least that was the combination for a 1982. 1981 is not listed but I'm betting it's the same.

The springs above the slides should all be the same length as well. If they are significantly different then that's another indication of a PO at work.

[tom203]

I stumbled across this ebay seller- he has lots of suzuki carb parts. Search his store and get all four of your carbs identical.
Personally, I would avoid K&L carb kits

http://www.ebay.com/itm/NOS-GS650-GS-650-CARB-MIKUNI-CARB-CARBURETOR-JET-HOLDER-270-Y-7-NOZZLE-81-83-/291635228538?hash=item43e6d06f7a:g:ge4AAOSwHQ9WaDg6&vxp=mtr

[dackcommabig]

I have 120 mains with pod filters. I have ordered 2 new springs and removed another washer shim. Gonna take her out here in a bit and see how it goes. You are all correct, I have been dealing with PO issues since I got it, but wrenching is fun.