pilot jets

[motoman]

Could you post a pic of those?

Your listed XJ has the same style as 81.............

[bikerphil]

Could you post a pic of those?

80-81 XS and 82 XJ ↓



78-79 XS ↓

[DGXSER]

Its that single taper of the second pic mix screw that lets it bind up in the hole of the carb throat. The upper one, the screw hits that "seat" before it wedges in the hole.

[motoman]

Those nice pics lend to no confusion there bikerphil!..

[GLoweVA]

Ureaka!

Here is an interesting finding. I have a scrap carb body laying around, the 80-81 style. So I decided to cut it open to determine exactly where does the air jet path intersect with the jet. Well, pictures will have to come later as my cell phone will not focus in that tight. However, I can confirm that the pilot air jet pathway enters the fuel path downstream of where the pilot jet end seats. So there is no way for those holes to control the amount of air coming into the fuel stream.

That being said, I know for certain that the number of holes has made a huge difference in how bikes I and other XSives have owned have run. So it does have an affect on the operation, just not sure how at the moment.

I knew it! I did a similar fact finding, but I didn't cut my carbs apart, but I came to the same conclusion. The pilot fuel/air mix IS downstream of the pilot jet seat/nozzle!
When I ordered replacement jets for my 80SG, they came in with no holes, but looked and measured exactly the same. I put them in a month ago and they still work just fine.
I'm thinking that the 6 side holes are for those carbs that have the crossover hole and thus the pilot tower is plugged, but I haven't been able to confirm this just yet.
On another note, the 8 holed ones I got had the wrong metering hole size and thus wouldn't have worked.