I,m running rich too?

[tonka1wlf]

I asked dealer about gas mileage on my 81 xs an he said i should get about 40 ,mine is getting around 20.Had carbs cleaned 3 yrs ago by a Harley mechanic(new valves an seats)cause i was leaking an still does sometimes Anyway don,t have a manual for bike and i think carbs are stock,what should the jets size be and what should mixture screws be set at ?Bike runs good an smooth but pop's alot when decel and loads up a little when idleing? Any ideas?

[planedick]

Idle mix screws

should be set about 1 1/2 turns out from a light seat. Run it at that setting for a little while and read the plugs and make adjustments accordingly.

[Snow]

40mpg? That's a bit optimistic for most... I got 32 yesterday at fill-up...course I have a wee bit of carb work to do. If your carbs are leaking, your needle seats/valves are faulty and you *will* be running rich.

Harley mechanic? 'round here, we call those "guys with duct tape"

[mro]

what should the jets size be and what should mixture screws be set

Depends om model/tear

BS34 11 carbs
starter jet on the E and F = #40 ...on the SF = #32.5
main jet = 137.5
pilot jet = 42.5
air jet-main = 140
air jet pilot = 180
float height = 25.7mm

BS34 111 carbs
starter jet on the G and H = #25
main jet = 115 (1 & 4 cylinders), 120 (2 & 3 cylinders)
SG main jet (1 & 4) = 110, 120 (2 & 3 cylinders)
pilot jet = 42.5
air jet-main = 140
air jet pilot = 185
float height = 23mm

Above covers most of em.
Have found main jets to be same on all 4 cylinders on several XSes and they ran without problems.

After three years....would not hurt to clean/adjust carbs.
Info in tech tips......

would expect 32 to 37 mpg as an average depending how you ride.


mro

[tonka1wlf]

Model/year

What i can find about my bike is that it is a '81 XS 1100,don't see anywhere or know if it is a G or H,title just says 1100. Engine family is,BYA110044A2 and displacement is,1102cc an also running mukini 4 carb,all stock bike i believe.

[John]

look on the steering neck for the vin. It will be stamped in on one side of the neck, and on a tag on the other side.

[tonka1wlf]

It say's 4RO- vin # and i forgot it's a Eleven special not a midnight special

[John]

4R0 is an 81 SH aka Special.

[tonka1wlf]

OK, thanks So i should follow MRO's specs for a G or H model? Also carbs would be 111's?

[pggg]

If the float valves 'still leak sometimes' then there's the bad fuel economy right there. I'd check the petcock filters, they may be damaged, letting debris into the carbs' fuel valves, new fuel hoses might be an idea too

[skids]

I have opened 3 sets of carbs for Model E's and all had #210 pilot air jets...

Originally posted by mro

Depends om model/tear

BS34 11 carbs
starter jet on the E and F = #40 ...on the SF = #32.5
main jet = 137.5
pilot jet = 42.5
air jet-main = 140
air jet pilot = 180
float height = 25.7mm
(snip)
mro

[pggg]

Hey Skids, the 4 sets of 78' carbs I have, 3 have the 180 air jets and 1 set had the 210's, the clymer manual I have shows 180's as stock 78 size, the 210's are likely a US emission thing?

[skids]

Good question. I would say that maybe it has to do with the mile-high city (Denver area), but one set cam from Washington.

Originally posted by pggg
Hey Skids, the 4 sets of 78' carbs I have, 3 have the 180 air jets and 1 set had the 210's, the clymer manual I have shows 180's as stock 78 size, the 210's are likely a US emission thing?

[mro]

Carb info from Yammy manual.

With only a few exceptions have only worked on stock XS's.
(hot rod don't count as it has the flat slides)
On the stockers only difference have found from manual has been that most have had same mains on all four carbs, only a couple had one up in the middle two cylinders.


mro

[tonka1wlf]

Got carbs off, main jet is 117.5 or 1175?Also Carbs on left side where pretty dirty,(Rusty gas tank) I thinks that's cause it sat leaning in that position .Well i'm cleaning it up just wanted to know if that jet number is ok?