Very specific carb question

[Guest]

Hey guys, I have a question for any carb experts. Trying to keep it simple, I'm trying to dial in GS550 carbs with a dynojet jet kit and pods, and have found some mis matched carbs! CV style, 1980 to 1982. I started to check everything when I found the emulsion tubes didn't match! There was two types, three of the wrong one and one correct. I found I had some carbs with the correct tubes so I'm good there... so the question there are two carbs that have a small hole drilled directly below the pilot jet, and two that don't. Does anyone know what is correct for this bike or which one I should go with? I do have two more carb bodies with the holes, but I'll have to transfer the pressed in air jet dynojet things or get two more...

Thanks I have found lots of great stuff on here to keep my GS' running!

[Steve]

"Below the pilot jet" should only have a rubber plug. Kinda hard to drill a hole in that.

How large is this hole? I have a sneaking suspicion that you might be mis-identifying some parts of the carbs.

And what makes you so sure that one is right and three are wrong, and not the other way around?

.

[prosolar]

OK, that should read above the pilot jet, and it's in the throttle bore. It's very small. smaller than my smallest drill bit.

With the emulsion tubes I did some research on the stock unit, part number and visuals, and compared to what I have.

[prosolar]

Here's the two different emulsion tubes

[prosolar]

next to where the emulsion tube goes is the smaller hole.

[Steve]

Let me know what emulsion tube you need, I have a few spares.

I have seen some carbs with that small hole in the throat, but have not noticed any pattern? In other words, I can't say if it's the 550s that have it or just the '82s that have it, etc.

Have you compared the number on the side of the carb body to what should be there?

.

[prosolar]

I found the tubes around my shop, I have spares. The numbers on the sides of the carbs is too faint and old to read, and I haven't come across what that number should be.

[Frank Z.]

Hole indicates 16-valve carbs; no hole carbs are for 8-valvers... at least for 1000/1100 cc series.

[prosolar]

Thanks Frank. I could epoxy the two holes....

[Steve]

Before you epoxy the holes, keep in mind that there are two different types of pilot jets. Some have holes in the sides, others don't.

It might be that one of those types NEEDS the holes in the throat. Epoxy them closed, you will change the function of the carbs, making jetting changes rather frustrating.

.