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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: White Dog on October 03, 2016, 05:10:42 PM

Title: Quantity of gas in tank
Post by: White Dog on October 03, 2016, 05:10:42 PM
Anyone care to speculate how much gas remains in the K75 tank when I can see the raised portion of the inside just looking down into the fill hole.  I barely have enough gas in my tank to slosh it from one side of this hump to the other and want to adjust my sending unit wheel so the light does not come on so soon.  It is consistently coming on around 130 miles but I can only squeeze just under 3 gallons of gas to fill the tank, making me think the light is premature.  I'm thinking I need to adjust the sending unit to delay the light to, say, 150 miles, then I can start looking for a station.  Admittedly, I am trying to do this the easiest way and avoid draining the tank, then pouring gas back in it.  Seems to be a pain so a best estimate might work for me.
Title: Re: Quantity of gas in tank
Post by: Martin on October 03, 2016, 05:34:31 PM
Empty your tank, put in the amount you require to be in the tank when the light comes on. Then adjust the float level so the light comes on by moving the adjustment toothed wheel on the sender. Check the sender by slightly lifting the float, the light should go out if you have adjusted it correctly.
Regards Martin.
Title: Re: Quantity of gas in tank
Post by: Martin on October 03, 2016, 05:37:59 PM
As a safety precaution use fuel resistant gloves while working with the fuel in the tank.
Regards Martin.
Title: Re: Quantity of gas in tank
Post by: Laitch on October 03, 2016, 06:42:47 PM
Here are a couple of Kennybobby's excellent photos further clarifying the mode and means of adjusting one of these gizmos as described and illustrated in RBM's original post. Siphoning fuel from the tank should make things even clearer. I don't know which way to pry that thing to increase the miles before the bulb lights but if I were doing it, I'd move it only one tooth-value at a time then see how that worked. Explanations—such as they are—have been written as captions.

Title: Re: Quantity of gas in tank
Post by: White Dog on October 03, 2016, 10:57:22 PM
Martin, I was trying to avoid messing with emptying the tank and was hoping someone with the expertise of a K75 would know how much gas would be in the botttom section of the tank.  I don't visualize having to move the adjustment wheel too much as I want to delay the light from coming on about 40 miles before I seriously look to fill up again.  The tank is listed as holding 19.5 liters (5.2 gallons) and the low fuel warning light is supposed to come on when approximately 5 liters (1.3 gallons) remain in the tank.  This is straight from the owners manual.  As I have posted, my light comes on early and a fill-up at that point takes less than 3 gallons.  I could squeeze another 40 miles and be within the criteria of the fuel pump requiring .7 gallons as someone mentioned in another post.  130 miles + 40 miles = 170 miles divided by 40 mpg (conservative) = 4.25 gallons needed.  Plenty of slack.
Title: Re: Quantity of gas in tank
Post by: Martin on October 03, 2016, 11:45:17 PM
They were never that accurate, and they can differ between bikes and you should never rely on it . It is not that hard to drain and remove the tank, I have just done it. I used a syphon squeeze pump to pump out the majority of the fuel. I removed  2 clips  and the 4 pin connector  then removed the two hoses. With the tank removed I tilted the tank with the rear end down and syphoned out the last remaining fuel into a separate container to check for water. With some Bricks suffering from corrosion due to water or alcohol it is good to periodically check the tank. If you don't wish to empty the tank run the bike until the light comes on then fill it up at the nearest petrol station the tank capacity minus the fill amount will give you the reserve amount. Let the tank go down to when the light comes on again and adjust accordingly.
Regards Martin.
Title: Re: Quantity of gas in tank
Post by: Motorhobo on October 04, 2016, 06:03:38 AM
I personally share White Dog's reluctance to remove the tank, even though I have the accumulator cup so it's literally two fuel hoses and the connector. The ends of the fuel hoses get frayed the more you do it and my tank dribbles fuel forever before finally tapering off, so I have to pull the hose off at the rail and plug it. It's not a big PITA but a PITA just the same and my approach to these 20+ year old bikes is if it ain't broke don't touch it

Maybe you should just live with the light until you have an inescapable reason to pull the tank. One will probably come up soon enough.

Title: Re: Quantity of gas in tank
Post by: Laitch on October 04, 2016, 08:50:44 AM
Ride the Fucking Krautburner until it sputters.  Add Krautjuice until the light comes on.
This is one of the most pathetic tough-guy imitations ever.
Title: Re: Quantity of gas in tank
Post by: kmev on October 04, 2016, 09:08:57 AM
On my 1994, the light comes on consistently between 168 and 175 miles. At this point a good portion of that hump if exposed. It will then take 3.4 US gallons to fill the tank. On one or two occasions I had a bit over 200 miles on the trip meter, and then added 4 gallons - I could barely see any fuel in the tank at this point.

There is some info suggesting the tank capacity was reduced to approximately 4.5 gallon in the later years. In my observations neither the owners manual nor the service manual was ever changed following their release for the original 1985 model (at least I have never seen an updated manual). I am not alarmed when that hump is exposed, but I do not assume I have over 5 gallons to start with.
Title: Re: Quantity of gas in tank
Post by: jakgieger on October 04, 2016, 09:10:27 AM
Ride the Fucking Krautburner until it sputters.  Add Krautjuice until the light comes on.
Acute, perhaps your pithy observations would be more relevant and noteworthy if you added your location and motorcycle/s to your signature line :bmwsmile. 
Title: Re: Quantity of gas in tank
Post by: Laitch on October 04, 2016, 09:19:04 AM
Acute, perhaps your pithy observations would be more relevant and noteworthy if you added your location and motorcycle/s to your signature line :bmwsmile.
Wouldn't hurt if they were accurate, too. The possibilities here for personal growth are tremendous.
Title: Re: Quantity of gas in tank
Post by: Motorhobo on October 04, 2016, 09:25:51 AM
Acute, perhaps your pithy observations would be more relevant and noteworthy if you added your location and motorcycle/s to your signature line :bmwsmile.

He's not gonna divulge his location -- he's probably got a posse of Krauts after him with burning bricks.
Title: Re: Quantity of gas in tank
Post by: The Mighty Gryphon on October 04, 2016, 12:33:30 PM
I have a nagging suspicion that AT is an alter ego of our founder.
Title: Re: Quantity of gas in tank
Post by: Filmcamera on October 04, 2016, 02:04:43 PM
Quote
I have a nagging suspicion that AT is an alter ego of our founder.

Funny I was thinking the same...
Title: Re: Quantity of gas in tank
Post by: bocutter Ed on October 04, 2016, 02:46:24 PM
I have a nagging suspicion that AT is an alter ego of our founder.
You'll know for sure if the skull gets a case of red-eye ...
Title: Re: Quantity of gas in tank
Post by: Martin on October 04, 2016, 03:43:23 PM
I smell a rat. Possibly a Cheezconsin rat.  :dunno
Title: Re: Quantity of gas in tank
Post by: White Dog on October 04, 2016, 06:27:11 PM
To get this back on original point, what is the purpose of the white bulb on the end of the rod which connects to the gas sending unit?  I was able to reach in the tank.  Moving the rod up and down had no effect on the gas warning light.  I had previously pumped most of the gas from the tank so that the white bulb was practically on the bottom of the tank.  I found a 5 liter gas container at Lowe's and put 1.31 gallons of gas in  it and poured that into my tank.  The light did not come on.  So, this raises a couple questions.  1) Did I blow a fuse messing with the sending unit? Or,  2) Did I have more fuel in the tank now than when the light first came on?  I'm undecided what I should do next--run it until it quits or fill the tank and see what the warning light does and see what the miles are.  Either way, I'll carry an extra gallon of gas with me, just in case.  I will check the fuse later tonight.
Title: Re: Quantity of gas in tank
Post by: jaxon on October 04, 2016, 07:16:22 PM
White bulb is the float. Like a toilet.

Jiggle the handle.
Title: Re: Quantity of gas in tank
Post by: Laitch on October 04, 2016, 07:31:46 PM
White bulb is the float. . . . Jiggle the handle.
+1
So, this raises a couple questions.
. . . run it until it quits . . .
+1
Title: Re: Quantity of gas in tank
Post by: White Dog on October 04, 2016, 08:58:11 PM
Fuse tested fine.  Me thinks I have a K75 with a smaller capacity tank someone mentioned, so maybe the 130 miles is all I'll get before warning light comes on.  I'll take a deep breath, get my 5L gas container refilled and see how far 5L of gas takes me.  I zeroed my trip meter after dumping the first container in the almost empty tank so I "should" get a better idea of what is happening.

BTW, after pumping most of the gas out, dumping 5L of gas raised the level of gas to the next to highest ridge in the hump inside the tank.
Title: Re: Quantity of gas in tank
Post by: Laitch on October 05, 2016, 12:01:21 AM
There is some info suggesting the tank capacity was reduced to approximately 4.5 gallon in the later years.
There's a lot of information suggesting a lot of conclusions that have no basis in fact. It helps if it's got a reliable source.

I believe the most accurate way to know a K-bike's tank capacity is to fill the tank to capacity then empty it completely and measure the amount emptied.

The way to learn your bike's traveling range using the light has been mentioned several times in several threads. Fill the tank, record the odometer reading, ride until the fuel bulb is lit, stop, record that reading then subtract the first reading from the second. Remove your helmet. Write the difference from that computation in reverse on your forehead. Note the odometer reading again.

Start riding until the bike sputters to a stop, then record that odometer reading. Subtract your second odometer reading from your third. Remove your helmet. Add the difference of the latest computation to the figure you see on your forehead in the rear view mirror. The sum of that computation is the total miles you'll probably get from a full tank at an average speed—your approximate total range depending upon wind direction, wind speed, elevation, gradient, average ground speed, air temperature, and total weight including passenger and cargo.

You can then tattoo that figure to your forearm for future reference in celtic script or the font of your choice.
Title: Re: Quantity of gas in tank
Post by: Motorhobo on October 05, 2016, 07:39:36 AM
The light on all four of the K75s I've owned also comes on at about 130 miles. My method is unscientific but has worked for me for almost 17 years.

130: Get to the town's Citgo at next opportunity because it's reputed to have less ethanol.
150: Start thinking more seriously about getting gas.
160: Start thinking even more seriously about getting gas.
170: Get gas now.
180: Obsess about getting gas.
190+:  Shit pants about getting gas.

Fortunately, I've never been in the 190+ range so can't say what riding a motorcycle with a load of shit in the pants is like. I imagine it to be uncomfortable and hard on the self-esteem, so I've only let it get to 180 once and don't intend to do it again, even though I'd probably easily get to 200 considering the capacity and mpg.

If you want to get more exacting than that, feel free, but I don't see how that's going to enhance your riding experience or fueling practice much. In any case, at 180 how far you go is dependent on how much fuel your machine has consumed during the burning of that particular tank, so there's going to always be an element of luck-pushing there.

Also -- riding with partially submerged or unsubmerged fuel tank is not supposed to be good for the pump -- which is why I usually fuel up well below 160.

My $0.02....



Title: Re: Quantity of gas in tank
Post by: White Dog on October 05, 2016, 09:39:14 AM
On my original venture, my light came on at 130 miles.  I ran an additional 23 miles before pumping some of the gas out of the tank.  No way to know how much that was.  I had to disconnect the gas line at the rail and crank the engine and allow the gas to run into my large gas can I use for lawnmowers.  That got the level of gas down below the hump in the tank.  When I raised the arm with the white bulb, the warning light did not go off, which further confused me. Dang.  I would have thought the light would go off.  I added 1.3 gallons of gas and the light was off when I went for a short ride.  Based on previous mpg checks, I can go about another 40 miles before I run dry.  If the light comes on, I'll make note of the mileage and continue until I run it dry, then fill the tank.

UPDATE  The warning light did come on after 12 miles or so, which tells me I had something less than a gallon of gas left.  My hand is too large to manipulate a screwdriver on the adjustment wheel.  Also, the wires are very close to the wheel and I was fearful of shorting something out.  Therefore, I have decided to leave things as are.  I know I can go 150 miles, maybe 160 if I'm riding easy so I'll try to ignore the warning light.  Where's my black electrical tape?  My only other options are to find someone either with small hands or who has done this adjustment before or pay the dealer shop to adjust it. 
When I filled the tank this afternoon, I could only get 2.5 gallons in it from the pump but I figure I had about 1 gallon already in it, thus 3.5 gallons  seems to be be the max capacity for normal fill ups.  Sitting on the cycle and looking into the tank, the flap touches the gas so I assume I filled the tank to its capacity.  Easier on the wallet, but fill ups come sooner than I would like.
Title: Re: Quantity of gas in tank
Post by: White Dog on October 05, 2016, 09:19:58 PM
Just thought of something else.  Is the sending unit a "one way fit" in the bottom of the tank?  If not, maybe mine has been R/R and installed incorrectly.  The white float on the rod is on the right hand side of the tank.  Accessing the adjustment wheel is a tight fit inside the tank.
Title: Re: Quantity of gas in tank
Post by: The Dude on October 06, 2016, 05:02:03 AM
Ride the Fucking Krautburner until it sputters.  Add Krautjuice until the light comes on.
No!
Add krautjuice until the light goes OFF.
Title: Re: Quantity of gas in tank
Post by: Laitch on October 06, 2016, 10:53:55 AM
No!
Add krautjuice until the light goes OFF.
Now you're playing with fire, Dude! Didn't you see that avatar. :yow
Title: Re: Quantity of gas in tank
Post by: The Dude on October 06, 2016, 03:38:46 PM
Now you're playing with fire, Dude! Didn't you see that avatar. :yow

No Laitch, these men are nihilist there is nothing to be afraid of. :neener: