pass everything but a gas station

[DiverRay]

Correct 110 mains in middle carbs 2/3 and 120 mains in outside 1/4
pretty sure that is what was in there stock form but i may be mistaken. Has happened several times in restoring this bike lol

Yeah, you have that wrong! the INSIDE two had the ONE SIZE larger mains to "help cool" them. I would go back to 120 across, or even 117.5 all around. Your choice, the 117.5 will make about 1mpg or so difference, so it may not be worth the cost and time.
Just my $0.02, YMMV

[MPittma100]

Correct 110 mains in middle carbs 2/3 and 120 mains in outside 1/4
pretty sure that is what was in there stock form but i may be mistaken. Has happened several times in restoring this bike lol

The larger jets are to be installed in the middle (2&3) carbs. Reason is to provide those "harder to cool" cylinders a little more fuel. Richer is cooler, leaner is hotter.

1978 & 1979 XS1100s carburetor jets were the same in all four - but larger. It was a US government emission thing to lean them out.

[mack]

ya but he

is listening and thinking now on his own, how many of us have reversed this. Good work Justin, now change them around ! Now your really part of the crew!

[Bonz]

Jets still could be OK, iffin' he remembered wrong and smaller ones are already on the outside.

[MPittma100]

Agreed

is listening and thinking now on his own, how many of us have reversed this. Good work Justin, now change them around ! Now your really part of the crew!

Yes, good work. That's why we have success here by encouraging each other to attempt these repairs on our worthy steeds.

Who's to say that reversing these jets ever did any damage anyway, right?

[justinc1081]

Its that riding fever that causes my mistakes lol
Ill swap those jets back around tonight, put the 120's in middle and 110's in outside, does seem to start falling on its face around 7k rpm
Fuel economy has improved but not yet at the 25mpg goal yet.
She is getting there!
I really do appreciate all of your help, this project would have never gotten started had i not found this forum

[Bonz]

Do you have 115 mains available? 110's and 120's are a wide spread. If 115's are available, try those in the outer carbs. Standard model needles and Special model needles are different tapers, so be sure you don't go too lean, i.e., 110's for extended highway running as it has been known to cause piston holes or something like that. My source for that is 3Phase, see if he chimes in to correct me.

My 80SG is stock with 110's across the board, staggered jetting was not used, probably because it didn't make much difference. I run 107.5's at 7200' elevation. Superb performance and plug color, even at the top of Pikes Peak (14,110') last summer at Colorado Rally 2014.

Would go back to 110's if I lived at a normal elevation. I get around 37-39 mpg in normal riding and low-mid 40's when leading the Colorado Rally 2014 or following in the pack like the Durango Rally 2011. Smooth and consistent riding makes for a lot better gas mileage.

[3Phase]

Nah, you got it one, Bonz!

The '80/'81 Specials and Standards have different needles and jetting.

'80/'81 Standard Main Jets: 115-120-120-115
'80/'81 Special Main Jets: 110-110-110-110

I don't have the needle numbers handy but the Specials and Midnight Specials share a common short, pointy, needle that's still available.

Standard needles are longer and not as pointy but they're no longer available new so they're almost impossible to find even used. You can replace them with Special needles but if the jets aren't changed to match the needles, the engine will run rich.


The '78/'79 style needles are still available so I use them with slightly richer Mains in my '80G: 117.5-120-120-117.5
Before I rebuilt the engine and messed it up, it ran all day long at 36 to 42 MPG depending on speed, terrain and wind.

.