My 1982 GS 450 - journal thread

[Bammer07]

i took the carbs back apart tonight. i don't have the right snap ring pliers to get the needles out.

i realized that the needles are significantly different lengths. they are about 1/8" different or a little more. one of them is looser than the other. I think they were worked on and put back together wrong, at least one was. it wouldn't be the first carb part i've found put together wrong. the longer one seems more correct. i'll get the correct snap ring pliers tomorrow and figure it out.

Hey Bren, I'm a total noob with an '82 gs650gl and I have very similar looking plugs, the white smoke on the left tail pipe, and a cold exhaust pipe on cylinder 2. I've looked at the carb cleaning article, and put my carb through a cleaning, but I'm curious if I have the needle issue yours did. Did you take photos by chance that would show what an ill fitting needle looks like or how you would measure it? Are you measuring the height from the bottom of the slide? Might be a dumb question, but it's one of many I have about this bike! I'd love to get all 4 cylinders working properly.

[bren]

Hey Bren, I'm a total noob with an '82 gs650gl and I have very similar looking plugs, the white smoke on the left tail pipe, and a cold exhaust pipe on cylinder 2. I've looked at the carb cleaning article, and put my carb through a cleaning, but I'm curious if I have the needle issue yours did. Did you take photos by chance that would show what an ill fitting needle looks like or how you would measure it? Are you measuring the height from the bottom of the slide? Might be a dumb question, but it's one of many I have about this bike! I'd love to get all 4 cylinders working properly.

well in my case it didn't turn out to be related to the needle, it turned out to be wrongly adjusted idle jet metering screws. I had to turn them out a lot further than common wisdom would recommend (it was running very lean at the recommended 2 ish turns out and needed a couple more turns out on each carb to richen it up enough. It's currently set at around 5 turns out on each carb.) I didn't realize what a delicate balance that it is, between syncing the carbs, setting the idle throttle screw, and setting the idle fuel circuit. What I found was that because so little fuel was getting into the idle circuit, I had to prop the butterflies open a good bit more than the carbs liked for it to even idle at all, causing it to run weird. when I cranked open the idle jets, i found I could close the butterflies almost completely, and suddenly it would idle just fine.

the needle doesn't have any effect at idle. if you have one cylinder down, i'd check some other stuff first, check spark, check that the idle jet and related passages on that carb are very clean, check sync, check idle metering screw. if your jet needle was assembled wrong, you'd see it with the bowls off. the needle on my one carb that was assembled wrong was several mm shorter than the other, and you could tell just by looking. when I took the slides out, I found that the c clip that holds the needle into the slide wasn't seated all the way into its groove.

[Bammer07]

well in my case it didn't turn out to be related to the needle, it turned out to be wrongly adjusted idle jet metering screws. I had to turn them out a lot further than common wisdom would recommend (it was running very lean at the recommended 2 ish turns out and needed a couple more turns out on each carb to richen it up enough. It's currently set at around 5 turns out on each carb.) I didn't realize what a delicate balance that it is, between syncing the carbs, setting the idle throttle screw, and setting the idle fuel circuit. What I found was that because so little fuel was getting into the idle circuit, I had to prop the butterflies open a good bit more than the carbs liked for it to even idle at all, causing it to run weird. when I cranked open the idle jets, i found I could close the butterflies almost completely, and suddenly it would idle just fine.

the needle doesn't have any effect at idle. if you have one cylinder down, i'd check some other stuff first, check spark, check that the idle jet and related passages on that carb are very clean, check sync, check idle metering screw. if your jet needle was assembled wrong, you'd see it with the bowls off. the needle on my one carb that was assembled wrong was several mm shorter than the other, and you could tell just by looking. when I took the slides out, I found that the c clip that holds the needle into the slide wasn't seated all the way into its groove.

I'll make sure I check that all out, thank you! My plugs are all totally black and looking like they run very rich, so I wouldn't have thought to go nearly as far out with my adjustment screws (I'm at 1.5 turns due to the carbon fouling). This will be a tremendous help having your troubleshooting list!