Jet Needle thingie - just to be sure

On the stock 650R carb, just above the main jet, is a little sleeve (tube) about 3/8" long that the tapered part of the needle goes into. The hole in one end of the tube is slightly bigger than the other.

The bigger end of the tube goes UP, right? Or does the smaller end go up?

Thanks!

:thumbsup:

On the stock 650R carb, just above the main jet, is a little sleeve (tube) about 3/8" long that the tapered part of the needle goes into. The hole in one end of the tube is slightly bigger than the other.

The bigger end of the tube goes UP, right? Or does the smaller end go up?

Thanks!

:thumbsup:

Smaller end up.

Here in a snapshot from the 650R manual.

89789169-L.jpg

I think you are talking about the needle jet holder. Hard to tell from the drawing.

I'm sure he's talking about the needle jet (not to be confused with the jet needle or "needle" that is so often mistakenly called the needle jet). You'll find that it will only go in one way. Well, it will go in the wrong way but the needle jet holder won't seat or screw in properly if the needle jet is backwards. One end of the needle jet is ever so slightly larger in diameter than the other end.

The end facing you in this pic goes in first:

p8150037vz0.jpg

Right on, Hawk - - thanks. I finally figured it out yesterday. The tube diameter is .010 bigger on one end than on the other. That's enough to make it not go in the hole if you try to put it in upsidedown.

The confusion is in the HOLE sizes on each end. You have to talk about the hole diameters OR the tube diameters because the end with the bigger hole is the end with the smaller diameter tube.

Big hole up, small tube up.

As DB says, "The devil is in the details."

Right on, Hawk - - thanks. I finally figured it out yesterday. The tube diameter is .010 bigger on one end than on the other. That's enough to make it not go in the hole if you try to put it in upsidedown.

The confusion is in the HOLE sizes on each end. You have to talk about the hole diameters OR the tube diameters because the end with the bigger hole is the end with the smaller diameter tube.

Big hole up, small tube up.

As DB says, "The devil is in the details."

Bigger I.D/smaller O.D. up. That devil can be a real trouble maker.

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