Quick carb question for an '80G

[GLoweVA]

This should be quick, I've got an 80G (standard), nothing special as far as mods go, just a K&N air filter. I'm wondering about the rubber plugs in the carbs. They are the ones on the bowl side right next to the main jet.
Do these plugs belong here? I read several years ago that some bikes have them and some don't. There's a jet in there under the plug, but with the plug in there, how does that jet even function?
In the 7 years that I've had my bike I've cleaned the carbs about 4-5 times (following the guidance in this forum) and these plugs have always been in there. I was just wondering if they should be and what might result if i left them out.
Thanks again for any input.
-George

[natemoen]

The '80 year was a transition year for the xs carbs. those plugs are there to prevent to pilot jets from sucking gas directly from the bowl. The pilot jet is fed by a hole that connects into the main jet tunnel. On that style carb the main jet is much larger to compensate for this. On the later 80 and up style carbs the main jet drops down to a 110 or 120 instead of the 137.5 that should be in yours.

[Kit]

Um, so what happens if you don't have those plugs...?

[CatatonicBug]

Um, so what happens if you don't have those plugs...?

The carbs stop working well.

Basically, you get too much fuel through there, and the mixtures get all messed up. There should be a little bump in the bittom of the float bowl that sticks up and holds those rubber plugs up in there where they belong.

[natemoen]

Um, so what happens if you don't have those plugs...?

Depending on when in the 80 model year your bike was made you may or may not need them. Early model year needs them, later model year does not need them.

[GLoweVA]

Thanks Catatonic. Looks like I'll have to take the carbs back off the bike and check the main jet size and make sure that little hole is there. I'll also ckeck the bottom of the bowl for that bump. I'm sure it's there, because I never had the plugs 'drop' out before.
I guess that's what I get for asking the question AFTER I put the carbs back on the bike. Good news is, the bike is partially apart waiting on the cam plugs to get here for the valve cover.

Anybody have any luck at repairing very small holes/tears in the carb diaphrams?

[Kit]

OK, that's one more thing to check. How do I know if mine is the style that needs them or the style that doesn't? Is the float bowl the only thing that will indicate which it is, or is there something else on the carb body itself?

Off the top of my head, I don't remember if that bump is there on my bowls or not. My new pilot jets will be here Wednesday, I'll check then.

[natemoen]

OK, that's one more thing to check. How do I know if mine is the style that needs them or the style that doesn't? Is the float bowl the only thing that will indicate which it is, or is there something else on the carb body itself?

Off the top of my head, I don't remember if that bump is there on my bowls or not. My new pilot jets will be here Wednesday, I'll check then.

The only way to tell is to see if there is a crossover passage between the main jet tower and the pilot jet tower. Even the little nub in the bottom of the bowl is there even when the plug is not needed so that is of no help.

[CatatonicBug]

Nate's right. The bump in the float bowl may be there either way. Chances are, if the plugs are there, you need them though.

[Kit]

The only way to tell is to see if there is a crossover passage between the main jet tower and the pilot jet tower.

OK, good to know. Don't remember if there is or not, but I'll look when I open them up again Wednesday.

Chances are, if the plugs are there, you need them though.

That's the thing, though: they aren't there currently, and the POs have Mickey Moused the ol' girl so much, that I don't know if they are supposed to be or not. Thisis the first I've ever even heard about them. The crossover passage that Nate mentioned should be an easy way to determine that, though. Thanks to you both.

George, I hope I didn't hijack your thread too badly. Just sounded like we both had the same question.

[motoman]

Anybody have any luck at repairing very small holes/tears in the carb diaphrams?
__________________
So far......yes, and it's been a yr.+ and checked and all okay. Do NOT use Plasti-Dip! It WILL come off and make a mess in that tower and you'll have to spray carb-cleaner in there holding carbs upside down to get it out! What I found that has worked thus far on one tiny hole in one of my diaphrams is Fuser 143. This is an extreme bumper repair adhesive. Can only be had at your local automotive paint/finishes supplier. There are several different types listed on a chart for different applications, including dissimilar materials mating. Tis a two-part tube similar to configuration of epoxy tube. Runs approx. $20. The attaching application gun is a ratcheting squeeze type that pushes both products out into a twist-on mixing chamber bout 4in. long. and runs an approximate $40+- dollars and is used for ALL their products. That part is a one-time purchase. Product is black, and after pushed out the end is hot from chemical reaction mixing. One drop on tiny hole in diaphram will do ya'. Better to do if you have a couple other repairs to make such as fractured tupperware on a scoot, plastic bumper, or ANYTHING similar, as you have approx. 1.5min. before TOTAL set-up. From experience, better have pieces being put back together in correct location, or you'll have to live with where there at! Using for intended plastic bumper or bike tupperware repair, it IS sandable, primeable, and paintable. This stuff IS tougher than base material being repaired(have tested myself). The mixing chambers cost approx. $1.65 each and are a one-time use for obvious reasons. Found this to work on one of my diaphrams just on a wim, as the plasti-Dip had just made a mess when I took apart diaphram 6mo. later. Already had this product and application gun......so figured nothing to loose, plus tons of other uses and there are many other of there products for different applications, like glueing body panels instead of welding, which by the way is commonly done now replacing body panels and is used in factory assembly of body panels. Different product numbers represent different applications. Hope that helps.