Eats GAS, runs flooded-NOW what?

[Ivan]

Yup, on the highway I get about 100 miles out of a tank on my SG before going to reserve. And the special holds, what, somewhere around 3.5 gallons?

So.....between 27 and 30 MPG.

The XS is NOT designed for fuel mileage.

Actually it holds about 4.2 with the reserves. Just enough to go from Hutchinson to about 200 yards away from that gas station on 412 outside Tulsa.....

[Yard Dogg]

I don't understand why we have such differences in gas throughout the states. I think it's bull for people to be paying for crappy gas, that should be a class action law suit against someone. Sorry for the rant, I feel bad for y'all in Oklahoma.

[LoHo]

Yo, Dogg, it's a way to keep the regional economies going. Near the Corn Belt, they like to throw down some ethanol. In California, we add about .2% Capuccino for more peppy acceleration and better exhaust aroma. Around Seattle, a little heroin takes off the edge...for a while. In Kentucky and Tennessee, prayer is employed to stretch a couple of MPG out of a tank. In Texas, they just claim 55 MPG and challenge you to a fight if you question it.

[DELL82]

Update on carb problems, long post

The idle plug chop has #1#2#3 running perfect. #4 is black smutty and dry. Header pipe was very warm but cooler than other three.
Plug chop at 4000 RPM for 6 miles has same result. However the #4 is less black.

Went to garage and pulled level on bowl with hose on drain, level was perfect. Jets were in tight. Air passages were open.
Turned the idle adjust screw on #4 to it's stop and started bike. run few minutes and pipe was cool. Backed out 1/2 turn. Pipe got warmer and plug was still black. Backed out screw 1 turn and repeated test, same result but warmer pipe.

Pulled the carb cap off and removed the needle and diaphragm. Checked for diaphragm leaks, none. Emulsion tube was in correctly and checked out below also. Removed the large jet holding the emulsion tube and all looked good, replaced.

Removed the intake boot by backing into the air box. Screw in air jet was there. All openings clear.

PLEASE TELL ME WHAT I AM MISSING
STAN HUTCHINSON CAME OVER DURING SOME OF THE TEST AND WE ARE AT A LOSS AS TO WHY #4 IS RICH.
lost spark says that if #1 is good then #4 should have to be also. Pulled #4 plug and put in another plug against engine, got spark same as other cylinders.
Anxiously awaiting responses from the experts.
Dell82

[psycoreefer]

Did you try replacing the "black" #4 plug with either one from another cylinder or a new plug, and then checking it?
1. Once a plug is black it can take a lot for it to clean up
2. It could be that the plug is "fouled" and no longer sparking as it should so no amount of adjusting will change it
3. Could be you got a bad plug?

If a new plug turns equally black it could be that the idle hole in your carb body is "enlarged" so you may only need a fraction of a turn to get the right idle mix.

You said you checked the fuel level in #4 and it was "spot on", is that in comparison to the other 3, or in comparison to what you expected? If you didn't compare it to say #1 then that could still be your problem.

[DELL82]

I clean the plugs with a glass bead blaster, looks like new.
We used these to test.
I checked the fuel level on all four carbs, all good.
I also opened the plug gap to .040" to see if I could get bigger spark, it worked.
"need a fraction of a turn to get the right idle mix." 1/2 turn did not help. I don't think the hole is the problem because when I rebuilt the carbs it was Okay.

With the top and bottom of the carb off and the air cleaner side of the boot off there is not much that I cannot get to. So what problem should I look for? I can blow out all the areas except the choke(enrichment circuit) area. Is there something possible wrong with the circuit? It closes and opens, air passes through it OKay, what else.
Dell82

[psycoreefer]

Are you sure you got the o-ring and washer on that idle screw?

What happens if you put a clean plug in with that #4 idle screw seated and let it run, does the #4 plug still turn black?

[Ivan]

here is just an off the wall though that has caught me a couple times. On the needle spacer there is a little peg that has to seat into a hole in the carb slide. It can be a PITA to get seated in all the way and is difficult to see the difference unless directly beside another slide. If this peg isn't seated, it will cause a rich midrange.

Just a though since it looks like you have everything covered. The only other thing that comes to mind is an exhaust restriction on that cylinder. Pretty easy to test. Just put a vacuum gauge on that port and check the vacuum at idle, then rev it to about 3-4K rpm and see if the vacuum come back to the same or very close. If not, you have a restriction.

[bikerphil]

Don't know if you've done this, unscrew the spark plug cap from #4 and trim off 1/4" so new wire is exposed, then screw it back on. Might have a bad connection to that plug. JAT

[Larrym]

First, Make the Most of What You Have.

Dell82,

I'll go along with focusing attention on the carbs/fuel as a starting point but keep in mind that electrical and mechanical are also areas that need to be rock solid before the engine will run perfectly.

I'd suggest that you pull the rack off again. This time swap all the internal parts between #3 and #4 carbs. This wholesale "substitution" is a valid technique where if the problem transfers with the parts then you'll be a little closer to putting your finger on the offending part.

If the problem persists in #4 carb then it's likely either a flaw/problem in the #4 carb body or a mechanical/electrical bug affecting #4 cylinder.

Keep hunting for the "skunk in the woodpile". If you end up striking out and at "wit's end" then as a final option I'd suggest a total swap of the carbs with a known good "Test Bank". That would "Rule Out" your carbs as the source of the problem.





These are set up for an unmodifed bike: OEM airbox and 4 into 2 exhaust. As a last resort before you give up for the season.... You pay shipping both ways and a "donation" to your favorite charity:

Channel 11's home for "wayward" super-bikes and their owners.

[trbig]

Have you checked the compression on that cylinder?


Tod

[DELL82]

I have tried to answer you questions and will try the suggestions, hopefully tonight.

psycoreefer Are you sure you got the o-ring and washer on that idle screw?Not sure, will check tonight

What happens if you put a clean plug in with that #4 idle screw seated and let it run, does the #4 plug still turn black? will try

Have you checked the compression on that cylinder? No I haven't Tod

bikerphil I have trimmed the wires. We have spark on all four cylinders.

Ivan I am drawing a blank on your statement. "On the needle spacer there is a little peg that has to seat into a hole in the carb slide." Please explain.

Thanks everyone I will attempt the suggestions and report back
Thanks Again for the input
Dell82

[psycoreefer]

Ivan I am drawing a blank on your statement. "On the needle spacer there is a little peg that has to seat into a hole in the carb slide." Please explain.

Thanks everyone I will attempt the suggestions and report back
Thanks Again for the input
Dell82

If you took the needles out of the slides, by removing the circlip, the piece directly under the circlip that holds everything inside the slide "down" has some little posts on the bottom of it, one of them must align with a hole in the slide. If you look at the parts fiche the part with the "peg" is #13 on the carb fiche.

I didn't think it was possible to get that circlip back in if the thing wasn't aligned but I guess maybe it is....

[Crazcnuk]

"The XS is NOT designed for fuel mileage"

Actually the XS is rated fairly high for a bike of it's size and power.

Somewhere on this site it shows, but if I remember correctly the XS is rated at 38-42mpg (US depending on year. )

It's amazing how many people get in the 20's and think it's normal...

[Ivan]

"The XS is NOT designed for fuel mileage"

Actually the XS is rated fairly high for a bike of it's size and power.

Somewhere on this site it shows, but if I remember correctly the XS is rated at 38-42mpg (US depending on year. )

It's amazing how many people get in the 20's and think it's normal...

I attribute most of that to todays gas. Dad had a 6000 pound behemoth 76 T-Bird that would pull 22 all day long with a 460 and a crappy autolite carb. Todays gas would be lucky to see that thing pull 12. I don't know if Canada has bought into the EPA BS about "enviro-friendly" additives or not. If you don't have 1/4 ethanol and the ensuing water content and god knows what else in your fuel, its no wonder you get better mileage. Todays fuel, at least in the US, just doesn't have the BTU's per gallon that it did in the 70s and 80s.