How far on the red light?

[fredintoon]

I took advantage of my little 2-gallon jerrycan to run the experiment during a tour of northern Montana.
Bike:- XS11SG sidecar rig, 3.97 USG gas tank.
Conditions:- 95ºF
First test
Speed:- Just cruisin' 50 to 55 mph.
Red light comes on at 73 miles from full.
Gas actually runs another 10 miles before having to switch to reserve.
Finally get to a gas station still running at 93 miles. Filled with 3.9 gallons so mebbe I could have gone a few blocks further.
Second test
A bit faster, 55 to 60mph.
70 miles, 9 & 9.
Ran completely dry and dumped in my emergency 2 gallons.
Note that my bike has no windshield or fairing so is dealing with the drag coefficient of a fat old man plus the rig has a slightly smaller than stock rear tire (125/90-16 TwinTire) and is hauling a medium weight sidecar loaded with a weeksworth of luggage & my slim elegant wife so your bike should go further. Still and all, once the red light comes on you have ~20 miles to find gas.

[Crazcnuk]

That's actually not good.

Every vehicle made/sold in U.S. and Canada is supposed to be able to go 50km (30miles) once you hit empty, or reserve or whatever your vehicle has. I would have suspected they added the light because the petcocks didn't give enough range. Otherwise there is no reason to have the low fuel light.

[rockjok]

Yesterday I rode my sidecar rig over the Beartooth Highway and returned home thru Yellowstone park, 396 miles. In order to beat the 100+ degree afternoon temps I left at 3:30 am.

The first part is a boring 100 miles of interstate highway that I run at 70-75 mph. With my Special tank I'd hit reserve at 80 miles and be completely out at 95, within sight of exxon.

I've currently got a standard tank with no reserve light and aftermarket (Mikes XS) petcocks. At 75 miles I hit reserve and at 90 miles the two right cylinders started cutting out. I discovered that I could rock the rig back and forth and the two starving cylinders would run another half mile. Limped into the station on two cylinders.

The rest of the ride was mountainous with many miles run in lower gears and my speed was rarely over 50 mph. I had no problem getting 100 miles without hitting reserve.

My conclusion from this trip is that speed (wind resistance) is probably the biggest factor in gas mileage. Obviously higher RPMs in the twisties and over mountain passes are factors but I think they are of lesser importance.

Rob

[skippy344]

mileage varies by driving conditions...

After my recent mod, the coils, I am getting to 85 miles before I start to see the red light flicker.

I have been doing "city" driving. In other words, just to work and back, and maybe some local errands.

I may try to do some highway time this weekend. I may go to Houston and see Hippie Dave and his new 'busa.

From re-reading the tech tips, it sounds like I am NOT dialed in on my jetting.

My plugs are almost pure white after riding at 4000 RPMs for a few minutes and pullng the plugs on #1 and #2.

Looks like I may still be a little lean.

greg

[skids]

I am thinking that the light comes on to worn you that you are about to start losing power unless you switch over to reserve. I would hate to have the engine start sputteringing in the fast lane of rush hour traffic with the tailgaters...

Originally posted by Crazcnuk
That's actually not good.

Every vehicle made/sold in U.S. and Canada is supposed to be able to go 50km (30miles) once you hit empty, or reserve or whatever your vehicle has. I would have suspected they added the light because the petcocks didn't give enough range. Otherwise there is no reason to have the low fuel light.

[Crazcnuk]

Would make sense, except that none of my other bikes have ever been concerned about this.

The only bike I have ever had that had a fuel guage was the Shadow 1100. It has 2 tanks. The upper one is not 'read' by the fuel guage at all, the guage actually starts at 1/2 tank.

You drive for about 120-130kms or so before the guage even starts to move. Then it drops to E over the next 50-60kms. Then it will go below E for the next 50kms. All in all I could get around 230kms per tank. The Shadow has no warning lights, and no reserve.

Other than the Shadow, all the bikes, in my experience had the standard switch-to-reserve system where you had to reach under and turn onto reserve when the bike ran out of fuel. On the highway this meant when the engine died outright. Around town it might sputter for a bit first.

I have never had one with the warning light. My XS, of course has a fuel guage AND a reserve setting, just have no experience with it yet.

[fredintoon]

What were they smokin' eh?

Hi Crazcnuk,
You only have to look at the several weird harold design touches on the XS11, especially those from the Special sub-group, to theorize that the designers were most likely into extreme recreational drug use.
"Ooh wow! Let's have a little red light instead of a gas gauge! Yeah, cool! That should keep Mr. Octopus happy!"
Why not?

[scott0757]

My 80 XS 11 had the Pacifico fairing. I typically have the low fuel light come on about 90 miles and within a 1 or two miles after that, I have to switch to the reserve. I have never tried to run it dry, but my typical refill is about 3.4 gallons (US).

Best not get out too far in the boonies with this set-up without a refilling!

[Crazcnuk]

"designers were most likely into extreme recreational drug use"

Pretty much, although I suspect they just realized, at the last moment, that they had designed in a fuel sender unit, but didn't have any room on the fancy round tach, to put a fuel guage!

Then they discovered, that with the new final drive ratio ( to get into the 11's in the 1/4 mile) they all of a sudden couldn't make the required 30 miles on reserve, so they added the dash low-fuel light to meet the requirement.

Now nearly 30 years later, many of the bikes are having trouble getting the fuel economy required to go 30 miles after the light comes on.

"my typical refill is about 3.4 gallons"

Yours is a Special, it only came with a 3.96US gallon tank, so you know you are filling with just over 1/2 gallon to go. The standards came with 5.3US and 6.4US gallon tanks, depending on where you live.

I can only assume that all the people who are only getting 90 miles to tank are Specials, if you have a standard you should be getting at LEAST 150 miles to a tank. Even a special, getting 30mpg, should be getting close to 120 miles on a tank.

Many people claim 40 or more mpg, which would translate to around 150 miles for a Special and 200 - 240 miles to the tank on a Standard.

[DiverRay]

My standard gets about 160 miles before it starts to sputter. The fuel gauge doesn't work, so I just go on mileage. I fill it with 4.4 US gallons, as a rule. I am working on a 6 gallon tank, and will have it on "daily ride" in about a month. It should give me just over 200 miles before sputter.

[Crazcnuk]

I have got used to using the trip meter as my most accurate fuel indicator. I reset it when I refuel and go off it when deciding when to stop, more so than a guage, or light or reserver switchover.

On my Virago, though, the reset button is missing so I am back to the 'run it till it hits reserve, then look for a station' system

[skids]

Re: What were they smokin' eh?

I have to agree with you there! Yuk Yuk!

Originally posted by fredintoon
Hi Crazcnuk,
You only have to look at the several weird harold design touches on the XS11, especially those from the Special sub-group, to theorize that the designers were most likely into extreme recreational drug use.
"Ooh wow! Let's have a little red light instead of a gas gauge! Yeah, cool! That should keep Mr. Octopus happy!"
Why not?

[TopCatGr58]

Well,
I, too, have a special. Before I did the MikesXS coils mod I was getting the angry red eye around 90 miles. I had hoped that after the coil mod that I would be burning the fuel more efficiently and might get a little better mileage! But during my recent runs down to N. Carolina to run with Dean/Laxdad the light came on consistently at the 90 mile mark! I run on PRIME all the time since removing the Octy, and I've gone to about 110 to 115 miles before filling, have put in ~3.6 gallons, so I know I only have 20 miles to find a station, but usually my butt is ready to stop by then!
T.C.

[scott0757]

I had no idea there was that much variation between standard and special tank sizes! I like the special tank look more than the Stds, but if I plan some distance riding, may consider a tank swap. , at least for the trip. Do the Std tanks fit the Special's frame mounts? Anyone fiund a good after market tank?

I too have removed the octy once it developed a leak fuel (kind of defeated its purpose in life), but noticed no change in mileage (none was expected).

So I watch the light, use the trip reset and know where the gas stations are when I hit the 90 mile mark! Or else I'll be prepared to use my cell phone for an emergency delivery!

[eroellig]

It's an interesting topic. I'm just starting to drain a tank or two. I had filled my tank to the bottom of the cap neck and ran my tank down till the red light came on at 120 miles. It took 3.24 gallons to refill.

My bike is still tuned lean. I rode across the state a ways on a local road (65 mile round trip) and really didn't exceed 60mph for any length of time. The remainder of the milage is typical suburb type stop&go traffic.

Eric