pilot jets

[s63921c]

I'm wondering which kind of pilot jets my 1980lg came with-I followed a link to get them and didn't know some have holes,and it appears some don't. I found the size I need,just don't know what type. I know they've been changed in the past.

[Yard Dogg]

I ordered new ones for mine a while back. I ordered the ones without the side holes, but they sent me the ones with holes. One of my carb bodies is damaged at the seat so I used an old jet without the holes so it would seal at the threads, the rest have the holes. I haven't noticed a difference. It may be wrong, but it seams to be alright until I can find a new bank of carbs.

[natemoen]

You want the bs30/96 with 6 side holes in the 2-1-2-1 hole pattern. Don't get the 8 hole jet or the no hole jet. 6 holes is what was designed to work in these carbs.

42.5 is the stock jet size for your bike too.

[s63921c]

pilot types

thanks for the info Nathan. I tried looking through the forums,but couldn't find what I was looking for.

[Yard Dogg]

Here's the thing that throws me off. Those jets actually seal at the bottom, so I don't understand what function those side holes even have. After you put them in, the only way for any thing to get through, is at the tiny little hole in the end. What do they even do?

[natemoen]

Here's the thing that throws me off. Those jets actually seal at the bottom, so I don't understand what function those side holes even have. After you put them in, the only way for any thing to get through, is at the tiny little hole in the end. What do they even do?

Air mixture.

[DGXSER]

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.

[Yard Dogg]

I met a person the other day a few blocks away that has 2 XS11s and plenty of parts. I tried to get him to join here since I'm the only one in the area, but he said he doesn't have time for a forum. I am working on getting a nice bank of carbs from him though. I'll get him to join eventually.

[s63921c]

mixture screws

I've got the carbs apart and have some jets to change according to the chart-all 110's on mains,47.5's on the pilots-parts for the inner mains and stock pilots are ordered,but I seem to remember someone saying my idle mix screws should be tapered on ends-mine have a double stepbut are not stock-is this an issue?-have looked at schematics on bike bandit and other oem yamaha websites-don't even notice the mixture screws pictured or listed?

[bikerphil]

The double step type mixture screws are correct for the 80-81 carbs. That type fits down in a tunnel. The tapered point type are for the 78-79 carbs and the head of the screw would be exposed on top of the tunnel.

[natemoen]

47.5 seems a bit large on the pilots. Why 2 steps larger?

[s63921c]

Pilot jet

I think it was the only size up I could find at the time-I see on the jetsrus website now that the 45's are available there.I already ordered the stock size from them to replace them. If you think 45's would be better,I'll just order those. Thanks you guys for the input-I appreciate it. Tired of looking at it-just want to ride....

[natemoen]

Stock as a baseline is best to start with then make changes as necessary from there.

[s63921c]

Thanks again-I'll start from there and see what happens...

[Yard Dogg]

The double step type mixture screws are correct for the 80-81 carbs. That type fits down in a tunnel. The tapered point type are for the 78-79 carbs and the head of the screw would be exposed on top of the tunnel.

Could you post a pic of those?