Out of gas

concours said:

Yup, had it pinned >50% of the way...

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So you're a victim of circomstance?

MikeG said:

So you're a victim of circomstance?

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Well, yaesssss... I was tryin to make it so the K1600 & Bandito 1300 riders wouldn't fall asleep...

worntorn said:

Imagine driving your car with the fuel gauge disconnected . Then remove the fuel tank and replace it one that gives a hundred mile or so range.
You now have an auto version of a Commando Roadster.
I think most would get that fuel gauge hooked up again pronto!

Glen

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Years ago I had a mate that owned a mini van he didn't have a fuel gauge
He used to dip the tank
Mind you it had more than a 100 miles range I believe
One memorable time we were on our way to an autojumble it was a bitterly cold day and we saw an boy broken down on a BSA M20
We stopped to help just as he got it going
He was riding the bike with no seat !!!!
He was wearing an army great coat and just sat on the frame
Didn't even have an old cushion or anything!
He said he was on his way to the jumble just to by a seat !!!

concours said:

Well, yaesssss... I was tryin to make so the K1600 & Bandito 1300 riders wouldn't fall asleep...
View attachment 98671

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Right down the road from me but...Ya caan't git theya from heya

I didnt recognize the location in the photo because there wasn't any snow...

" It uses hydrostatic pressure that you program for your tank"

I'm still trying to envision the type of pressure transducer that can reliably discern the infantismal head pressure difference linearly, and accurately at a price point.
I'm skeptical.


Please share documentation?
Ty

Britbike850 said:

How many riders pop the cap to see how much fuel is left riding down the road…

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I do, regularly. I also have a GPS on my handlebars that keeps track of miles ridden since last fillup. Programmed to warn me at the 100 mile mark.

concours said:

I'm still trying to envision the type of pressure transducer that can reliably discern the infantismal head pressure difference linearly, and accurately at a price point.
I'm skeptical.

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I work in Product Development Engineering for Ashcroft, Inc. We are currently developing a low pressure transducer for the HVAC industry. Pressure ranges like 0.05 inch of water, full scale, with 1/4% accuracy. The base chip is an AMS PCAP-04, which is under $4 in quantity.

Perhaps I could get an implant? Tells me when I need to pee, rather than have to wait 'til halfway through a film/gig/journey etc

How does it deal with sloshing which must be pretty bad in a bike?

Onder said:

How does it deal with sloshing which must be pretty bad in a bike?

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Digital averaging is simple in firmware.

maylar said:

I work in Product Development Engineering for Ashcroft, Inc. We are currently developing a low pressure transducer for the HVAC industry. Pressure ranges like 0.05 inch of water, full scale, with 1/4% accuracy. The base chip is an AMS PCAP-04, which is under $4 in quantity.

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So, what are the pressures with gravity feed gasoline,
16" head full tank, 8" head near empty?

Edit: 8" full, near zero empty, assuming the transducer is at the petcock level

Sloshing doesn’t seem to make a difference…it uses an average over a small amount of time. I took a lot of time programming and was surprised how accurate it is…repeatable. I like having both taps open for the fuel flow and I am trusting it more each ride. Sometimes I do pop the cap just for insurance…it’s a hard habit to break
Rod

Both taps open is a good plan. A friend was riding his Rapide with one tap open, two up on a hot day climbing in the Sierra Nevadas. We were behind and saw a big puff of blue smoke then the seizure. It turned out that the screen on that tap was partially plugged. We think it caused lean running.
After cooling down the bike started and ran, but there was damage.

Glen

Of course there are low tech solutions:

concours said:

So, what are the pressures with gravity feed gasoline,
16" head full tank, 8" head near empty?

Edit: 8" full, near zero empty, assuming the transducer is at the petcock level

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Water is about 1.4 times as heavy as gasoline, so a transducer that could measure 8 inches of gas would be about 6 IWC. A transducer for 10 IWC (inches water column) would suffice.

I assume (incorrectly, perhaps?) that we all have a decent idea of how many miles we can comfortably travel on a tank of gas. When I had my Roadster tank, 90 miles was the comfort point and the reserve was only good for around 10 miles! With my Fastback tank the comfort point is around 120 miles with reserve being around 30.

The Roadster 'reserve' was laughable but on all other bikes of the era (no fuel gauges) I never had an issue at all with "ride until it sputters, turn on reserve, fill at next station."

FWIW, last year my wife's Ducati Diavel's fuel gauge failed while out on a ride. It showed 1/3 tank but she ran out of fuel on a two lane road out in the middle of nowhere. A bike with no fuel gauge but with a reserve would have been far better... I had to leave her at the side of the road with her bike (she refused to leave it) while I hunted for gas and something to carry it in. Found both 20 miles up the road at a little 7-11 type place.

I called the Ducati dealer in town a few days later to get a new fuel sender unit and they advised me not to bother, "It will just fail like the last one." They recommended a "fix" to disable the fuel readout completely and rely on mileage.

At some point the fuel is divided by the spine bump in the tank. We can only see one side when looking in. And the head pressure is only measured by one side right? How does that issue factor in to knowing how much fuel is left?

"I assume (incorrectly, perhaps?) that we all have a decent idea of how many miles we can comfortably travel on a tank of gas. When I had my Roadster tank, 90 miles was the comfort point and the reserve was only good for around 10 miles! With my Fastback tank the comfort point is around 120 miles with reserve being around 30."

I found that going with a set range works if you stick to the same old roads and terrain. Move away from that and the set range plan doesn't work so well.
My range on long trips , 2,000 to 3,000 miles, varied from 110 miles to empty and 180 miles to empty.
The variables are wind, hills and speed.
Cruising at 65 on the flat with a tailwind got the 180 mile range.
75 in the mountains with a headwind knocked that down to 110 miles. I was hoping and planning for at least 125 that time. An accurate fuel gauge would be very useful!

Glen

If this sensor works on pressure, how does it handle the pressure differences caused by hot and cold weather, bike parked in the sun, etc ?