First time carb disassembly/reassembly questions

[sultan]

'83 GS 650 GLD, 22K Miles.

OK, Carb #1 disassembled, dipped, cleaned off, blown out. Now I'm trying to piece together the re-assembly and adjustment. I keep seeing reference to this magical "air screw", which from the carb cleaning PDF, should be on the top of the engine side of the carb. Here's a picture of my #1 carb:

Is the thing with the red circle around it supposed to be the air screw? There's only a tiny hole in the middle. Am I missing something, or just completely off-base? How does this come out? How does one adjust this to 2 turns out when there's nothing to get hold of?

Also, the manual says that the float level should be 22.4 +/- 1mm. Looking at other posts, it seems that I should be measuring it at the red line here:

problem is, that at this measurement, pulling the float *up* in this case (the way gravity would pull it down), the float currently measures 26 mm above the inside lip. Moving this down to 22 mm wouldn't leave it much room to ... 'float'. I'd also have to bend the heck out of the 'tang' (that's the thing circled in yellow, right?) to limit it to 22 mm. Again, what am I getting wrong here? The previous posts I've been reading say that the floats almost never need adjusting, so this leads me to believe I'm doing something incorrectly.

Thanks to all for your expertise.

 

[80GS750]

your gonna laugh when you find out what you did wrong...


turn your floats over... they are installed upside down.

then you can measure it properly

and that screw is actually being covered by that plug you see...

take a pick and pull the cover out and you will find the screw underneath...

most guys on here just use a small drill bit to punch a hole big enough to get ahold of it, then pop it out

just dont drill too far cause you will hit the screw

 

[Guest]

Under that cap there is a small o-ring that should of been removed before dipping the bodies. Now it will be goo and I hope you can get it out.
You need to measure the float heigth with the float needle and seat in place. Let gravity push the needle down and measure from the stepdown from the hinge of the float. Your float isn't upside down. You're just holding it up.

 

[Steve]

Yup, floats are OK, just let them rest against the needles.

You sorta had the right idea, but working upside down has you confused. Yes, gravity will pull the floats down, but that opens the needles. The incoming fuel will cause the floats to ... well, ... float, making them rise. What you are measuring is the point where they will close off the needles. This is usually done by simply letting them rest against the spring-loaded float needles, making sure they don't compress the springs. If the springs are mushy, it's best to replace the float needles.

Oh, and when you let the floats down, that surface just to the right of your red line will be rather parallel to the carb body, making it easy to measure.

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[sultan]

. This is usually done by simply letting them rest against the spring-loaded float needles, making sure they don't compress the springs.
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Ah. I think I might be starting to get it. So, THIS is the 'tang'?:

and you adjust the float height with the float needle in, with the tang from the floats *resting on* but *not compressing* the float needle and spring?

Is the hidden air screw and the mechanical idle/balance adjustment the *only* things that are "adjustable"? Everything else just screws in and "seats"?

And *sigh*, any tricks to getting out the now-gummy air screw? (The second carb was soaking as I was posting this last night. Grrr. Now I have two of them to get out and re-soak.)

Thanks to all for the advice.

 

[80GS750]

sorry about the misdirection on the floats...

they looked upside down to me... lol

 

[Roostabunny]

When I first got my bike and wanted to check the mixtures and sync, I carefully drilled the hole in the air screw caps to 1/8" I think and then used a screw to "corkscrew" the thing out. It's press fit, so it requires more patience than force.

I went through the carb rebuild process a couple of weeks ago - this thread has an OK picture of measuring float heights.

I used a thin gauge piece of wire with about a 2mm radius hook on the end to fish out my air screw o-rings. If it's really mush already, then probably the hook combined with liberal amounts of spray carb cleaner. Don't lose the tiny metal washer.

If you haven't already, go to Robert Barr's site and get yourself a set of new o-rings.

And, yes, that's the "tang". If you need to adjust it just be careful about twisting the floats - measure on both sides afterwards to make sure they're level.

 

[Steve]

Ah. I think I might be starting to get it. So, THIS is the 'tang'?:

and you adjust the float height with the float needle in, with the tang from the floats *resting on* but *not compressing* the float needle and spring?

Is the hidden air screw and the mechanical idle/balance adjustment the *only* things that are "adjustable"? Everything else just screws in and "seats"?

And *sigh*, any tricks to getting out the now-gummy air screw? (The second carb was soaking as I was posting this last night. Grrr. Now I have two of them to get out and re-soak.)

Thanks to all for the advice.

Yes.

Yes.

Yes and yes.

Get a brand-new screwdriver that fits the screw. Work the screw in both directions to break it free.
If all that fails, soak the carb again, until the gummy used-to-be o-ring dissolves. 8-[

TIP: When you are adjusting the float height, examine the spring tension on the float needle. Most of the time, there is enough tension to prevent the floats from compressing them, but some springs will allow a little compression with just the weight of the floats. If the springs don't compress unless you push down on the floats, you don't have to do anything special, just measure the height with the floats restingn on the needles. If the floats DO compress the springs a bit, turn the carb sidways so gravity is not pulling down on the floats. This will allow you to swing the floats until they contact the needles and get your measurement. In the meantime, order new needle valves from Z1 Enterprises, they are only a few dollars each.

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