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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: achtung3 on October 10, 2013, 11:45:36 AM
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Ok! This may be question that has been asked a million times but I could not find in this forum.
What is the damage to my K75 if I keep using regular gas instead premium?
Please keep it simple on the answer I am not a mechanic or technical expert so i will probably get confused on a long technical scientific answer.
Thanks.
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Most likely nothing. My 93 K1100 runs perfectly fine on regular unleaded.
Are you experiencing pinging under load? That's the classic symptom that an engine requires gas with more octane. Octane is simply the gasolines ability to resist preignition in the burn process. Pinging is a clue that preignition is occurring.
No pinging? No worries.
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http://www.motobrick.com/index.php?topic=3724.0 (http://www.motobrick.com/index.php?topic=3724.0)
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87 k100rs
I make regular runs to Pensacola, Florida to see my gf. 900 miles each way. I've done this experiment, averaging about 65mph including stops. Running about 80mph down the highway. 97% of mileage is interstate
93 octane w ethanol. = 40 mpg
93 octane w/o ethanol when i can find it (about half the fillups) = 43mph
87 octane w ethanol = 42 mpg
87 octane w/o ethanol when I can find it (about half the fillups) = 44+ mpg
Then this during one 350 mile stretch with two fillups with 87 octane and NO booze! 48 mpg!!! And this is consistent EVERY time I go to Fla.
I get very similar results in my 2000 honda CRV when I make the same trip. normally that vehicle gets about 25 mpg no matter what Im doing or running. But I was able to do 500 miles with 87 Octane and w no boooze and got 30+ mpg!! Same stretch between Atlanta and Motngomery to exit 69 :2thumbup: to Flomaton.
SO! will someone....ANYONE ....PLEASE Tell the liberal, sky is falling, global warming proselytizing, everyone's gotta feel good and get a trophy generation, that PLAIN OLE GASOLINE WORKS and Boozin our fuel up DOESNT SAVE GAS!!!!!
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I'm pretty sure they don't add the booze to save gas, they add it because they can make it locally from locally farmed corn.
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I Just looked at a US riders Manual for K1100 and it said 89 AKI (US Mid grade rating).
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My bike likes gas, the octane is superfluous, though i think I get the best mileage on mid-grade.
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It also depends on altitude. Lower octane is okay at higher altitude, as peak cylinder pressure is lower. Though I noticed in most of the central plains, the octane ratings are actually (in order of price) 87 (e10) 85 (e0) 91 (e10).
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So 91 octane is the highest you guys can get at the pump in the States?
Here in NZ the 'Budget' Gas is 91, most places offer premium @ 95 and the odd place (where I usually fill up) has 98 at the pumps too.
Interesting!
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I think I got my answer from TTyler reply to my post.
I will look "under the seat" for the info on gas.
I've always thought that I was supposed to use Premium 91 octane, but I don't recall where I've heard that is ok to use regular once in a while. :riding: :riding:
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So 91 octane is the highest you guys can get at the pump in the States?
Here in NZ the 'Budget' Gas is 91, most places offer premium @ 95 and the odd place (where I usually fill up) has 98 at the pumps too.
Interesting!
Our ratings are not the same. Our 91 is like your 98.
We rate in AKI I think you rate RON.
http://en.wikipedia.org/wiki/Octane_rating (http://en.wikipedia.org/wiki/Octane_rating)
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I think I got my answer from TTyler reply to my post.
I will look "under the seat" for the info on gas.
I've always thought that I was supposed to use Premium 91 octane, but I don't recall where I've heard that is ok to use regular once in a while. :riding: :riding:
The 90s manual says mid or high octane. That's probably where you got it from.
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So 91 octane is the highest you guys can get at the pump in the States?
Here in NZ the 'Budget' Gas is 91, most places offer premium @ 95 and the odd place (where I usually fill up) has 98 at the pumps too.
Interesting!
Our ratings are not the same. Our 91 is like your 98.
We rate in AKI I think you rate RON.
http://en.wikipedia.org/wiki/Octane_rating (http://en.wikipedia.org/wiki/Octane_rating)
Ahhh yes! Makes sense!
ya learn something new everyday - Thanks!
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My K75 is a 1990, I will look in the manual.
My other bike says to use 97octane but I have not found a 97 here in California.
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I've been using Shell V-Power (99 plus some extra stuff) when near but if not, then 98 (5 % ethanol). I guess it would go fine with regular 95 (10 % ethanol) but at least theoretically it should run better with higher octane.
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My manual (1987) specifies 91-ROZ, a European standard roughly equivalent to regular 87 RON here in the states. Mine does fine on regular.
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Gas threads go like this:
I say, "there is no reason to run a higher octane gas unless your engine pings. Running a higher octane gas than needed just lightens your wallet. I have always run 87 with no problems."
Next someone says "but my bike runs better on higher octane."
Then someone says "no it doesn't, you just think it does."
"Does to"
"Does not"
etc
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Gas threads go like this:
I say, "there is no reason to run a higher octane gas unless your engine pings. Running a higher octane gas than needed just lightens your wallet. I have always run 87 with no problems."
Next someone says "but my bike runs better on higher octane."
Then someone says "no it doesn't, you just think it does."
"Does to"
"Does not"
etc
:clap:
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Smart phone ap called "Pure Gas"... finds gas with no corn. To me, that's worth the extra money.
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Ran a couple of tanks of 89 today on a 300 mile round trip since the K1100 manual said it was acceptable.
1st tank.....it was noticeably not happy. It was a cheap gas station but I was stuck with stopping there not. It got 41mpg with Odometer error corrected. A good bit of the run was at 70+ about 30 miles was city.
That said Ive done 45mpg on 91.
2nd tank was from Pilot. It was noticeably better running as soon as I started it and i cleared the lines with the new fuel. Maybe that cheap station was stale or it was really 87. It will probable be next weekend before I run through the rest of it. See how it does.
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The octane of the gas doesn't tell the story of how much energy is "in" the gas. Octane is just a shorthand way of saying "how hard is it to get this gas to burn".
Gasoline will ignite if you vaporize it and compress it. (Even without a spark plug). The issue being that with high-output engines that rely on tight tolerances and high compression (turbos, planes, etc) some gas would ignite too early in the power stroke cycle- before the piston is fully compressed, and before the plug would spark. So the explosion if gas almost tries to throw the piston and shaft "the wrong way"- the cylinders all end up fighting each other.
Higher octane gas won't ignite as easily. Lower octane gas may ignite if you look at it wrong.
It is completely true that ethanol has less stored energy than a similar volume of non-ethanol gas, though. (Independent of octane).
The thought on ethanol is that it makes the finite world oil reserves last a little longer. The calculus of all the petroleum it takes to MAKE ethanol (transport, fertilizer, etc) and the reduced energy created by ethanol makes us come out ahead in the end? That's above my pay grade.
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Whoa!!!!!!!!!!!!!!!
Wait a minute guys.
Is this the Prius forum where every ounce of gas is sacred??
Nope,This is the BMW FORUM where all of us are high end bike owners.
All this angst about 1 or 2 miles per gallon is below us.
If I put 3 gallons of high test instead of low test gas in my K bike the difference is about 20-30 cents a tank. It's insignificant.
I bet that if the same cheapo's went into a good pub and saw a premium brew for $1. more than the
standard swill for just 12oz. there would be not problem forking out the extra buck.
Just go for the high test and forget the small stuff.
Theres more important things to ponder.
Like why when you say motorcycle to most people in the USA, they think Harley Davidson.
Well, these are the same people who elected King Barack, the emperor of the north, twice.
So I guess that why they do that.
Pity !!!!!!!
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Ok, then....
I've heard that Citgo has the lowest ethanol content of all major other brands and that convenience store gas is suspect for high water contamination. Octane is one thing but I want as little ethanol and water in my fuel as possible.
Btw Citgo is Venezuelan and the guys who told me that about the ethanol and water contamination are Apple Pie Americans who work At the local reputable garage -- not The Chavez-lovin' type.
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Last tank of 89 was horrible. I usually hit 160 before I get the light. 140 I had the light and my MPG was 34.
Giving it one more shot of 89. This time with Chevron.
Correction 89
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little story about gasoline...
i can comfortable roll 180 on a tank of gas... just about any gas... at 180 it takes approx 4.4 gal almost every time...
this summer i rolled the brick of the corn outta the garage... it had set in an non-heated non-airconditioned garage in wisconsin for 50 weeks full of ethyl no corn with some stabil in there...
on my way to indiana i almost ran outta gas... i always fuel by 180... i was at 140 and my 10 mile fuel light came on... i pulled over and popped the cap... o my... almost dry... it took 5.1 gal...
i barely made it to get some more ethyl no corn... on that fresh tank at 180 it took 4.4 gal...
so there you go... old gas... even if its ethyl no corn... just donts have the energy as fresh...
j o
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Now (at least around here in the midwest) they are starting to use blended mixes.
http://thegazette.com/2013/09/16/new-regulation-could-widen-price-gap-between-ethanol-non-ethanol-fuels/ (http://thegazette.com/2013/09/16/new-regulation-could-widen-price-gap-between-ethanol-non-ethanol-fuels/)
Refineries are starting to deliver low 80's fuel and expecting the distribution terminals to either blend it with corn ethanol or with premium to make the minimum octane of 87.
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... it had set in an non-heated non-airconditioned garage in wisconsin for 50 weeks ...
That's bike abuse! You should be.... errrr.... I dunno. :nono
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I know this is an old post I'm replying to but here it is anyway. I run Turbo Blue Fuel, 116 Octane in my 1986 K100 RT. I get about 220 miles per tank and it runs awesome. At the time of this post it is costing me about $8.25 a gallon. It seems to give me significantly more power and the engine growls a little meaner, which I like.
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I use 87 or 89 octane in my K1100RS. I get about 220 miles per tank and it runs awesome. It seems to give me tremendous power and the engine growls like a meanie. All for under $3 a gallon at the time of this post.
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I run 87 moonshine blend during the riding season and put the 91 moonshine free in for the winter. I get 220 miles or more per tank, my three bikes run awesome and have excellent power. The 16valve 100 has an awesome growl and the 75's have a beautiful snarl above 4 grand. Right now I'm paying about $2.75 a gallon and burning about three tanks a week.
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My bike runs on 89 octane gasohol. I don't want more power because that would cause me to arrive at my destination sooner and that would mean I would be riding less. The six dollars or so that I save by not buying Turbo fuel I spend on coffee, cider donut holes, 89 octane fuel and T-shirts with important messages about planet preservation and vegan eateries.
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https://www.pure-gas.org/
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All my bikes seem to run just fine on regular octane fuel but I always try to use a Top Tier branded fuel in both my bikes and vehicles.
http://www.toptiergas.com
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Huge factor cage or bike is headwind, or tailwind, and anything between. MPG should be measured over a looooooong span. Keep track of every gallon used all summer with beginning mileage, end with fill up, then subtract from starting mileage, divide. Get back to us. Also, a 2.81 FD gear helps, as does an easy throttle.
Run it hard, mine, '84 KRS, sucks a lot of gas. Sip it or guzzle it, what ever turns yer crank. 40 mpg is friggen great IMHO. I always use pure gas 91 octane. If not available, highest octane ethanol. If I can't afford good gas, might as well hang it up.
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Huge factor cage or bike is headwind, or tailwind, and anything between.
Let's call the anything between abdomino-thoracicwind.
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I filled the brick up with 90 octane 100% gas tonight--$3.609 per gallon. Last time I bought gas at that place it was $3.109. They apparently haven't gotten the email from big oil to lower their price to pre-hurricane pricing. (Big oil probably hasn't sent that email yet.) The price for regular 87 non-corn is $3.059, but the handle was covered with a bag.
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I wouldn't complain too much, White Dog; that's a great price compared to up North. I just did a calculation and found out I would be paying the equivalent of $3.93 per US gallon up here in Canada. Premium 90 at the pump in the GTA at the moment is CA$1.30 per litre.
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rbm. I recently purchased and installed a new fuel sender unit and moved the geared wheel one notch CCW to delay the low fuel light illuminating. With the flap removed from my filler cap, I put 4.0 gallons of gas into the tank after riding 154 miles and still the light did not illuminate. I believe the capacity of my tank is the 4.2 gallon version. So, I was doubly nervous in that the light did not come on and the tank was almost dry. I may have pushed the limit of the fill up, as when I put it on the center stand and opened the filler cap, there was evidence where gas had slopped out of the tank. So, when this tank is consumed, I'll probably pull the sender unit and return the geared wheel to its original position. (Yeah, some might say to adjust it while its in the tank but fumbling with that method is how I broke off the gears of the original unit.) While I have it out of the tank I'll test for continuity of the light circuit.
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I believe the capacity of my tank is the 4.2 gallon version.
Twenty-one liters coverts to 5.55 US gallon (4.6 Imp gallon).
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I read on this forum that BMW decreased the size of the gas tank during the 90's, so it must be true.
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I think you are thinking Imperial gallons. The tanks hold 5.3 U.S. gallons which converts to 4.2 Imperial gallons. You were probably reading a post by someone in the U.K. or Canada.
My bikes are '92 and '94 models. All of them hold 5.3 gallons. I also get a consistant 180 miles on four gallons, and the low fuel light comes on at about 190 miles. These numbers are with the flapper removed.
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Mighty Gryphon, I looked in my tank last night prior to the fill up. Gas level was at the last ripple on the bottom of the tank. I squeezed 4.0 gallons to fill it with flapper removed. I live in the USA, not Canada. Wish I could get the MPG you say you get. 154 miles divided by 4.0 gallons =38.5 MPG.
The post about tank size change I remember seeing was this one from BMW MOA. beemerguru beemerguru is offline
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The other possibility was the change in tank capacity around '93 or so. I got a factory replacement tank when the paint peeled on a new K75 back then and immediately noticed a decrease in range.
Popped the tank off and compared it to another off an earlier K75. There was a change in the bottom design..took away about 1/2 gal.
Called BMW and got my old tank back..repainted it and got my 1/2 gal back.
Greg Hutchinson
R80G/S (4) 633CSi with 450K mile
'68 R60/2 '88 K100RS Special Edition
http://gregsgssite.shutterfly.com/
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AFAIK there are only 2 tank sizes (anyone?). All K100 and K75RT are 22 litres, all other K75 are 21 litres. I have one without the "change on the bottom" and it doesn't fit under the K75s fairing.
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Ed, My 1994 K75 RT and S models both have 21 liter tanks. With the flapper removed both will take about 5.3 gallons. Never heard of a 16 liter(4.2 gallons). I know there are several different part numbers for tanks, but I thought they were about the different mounting and the mounts for the battery covers. The capacity and size were essentially the same for all of them.
I do know that 21 liters translates to 4.2 Imp. gallons. But I'm sure they don't sell gas in Imp. gallons in North Carolina. :dunno
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My owners manual, page 28, indicates the tank holds 19.5 liters (5.2 gallons) and the low fuel light is supposed to come on "when approximately 5 liters (1.3 gal.) of fuel remain in the tank." Then I saw the posting on the BMW MOA referenced above, which made me wonder. With the first sender unit I had, the light popped on at 130 miles and I could easily go 150-160 miles before looking for a fill up. Then, I started messing with the geared wheel in an attempt to avoid having that bright idiot light glaring at me for 20-30 miles. That's when I stripped all the teeth off. So, I bought a new unit and this is the second fill up since installing. Honestly I do not recall ever putting more than 4.0 gallons in the tank, even with the flapper removed. If there is an easier way to completely empty the tank and refill to capacity, aside from siphoning or running the fuel pump, I'm all ears. In the meantime, let's all fill our tanks as we please and enjoy the rides!
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I've been using premium as long as I've owned the K. All my old British bikes demanded premium (as I remember Triumph specified 97 minimum, but that was back when premium was 100 octane.) I might try some mid grade just to see how it runs, though.
As mentioned, fresh fuel is almost mandatory. Especially with ethanol, the stuff rapidly loses its ability to ignite.
I tested samples from the different stations in the area. Most premium in the Nashville area contains about 5% ethanol. Exxon and Citgo came in lowest at about 3%.
BTW: My fuel light comes on with over 50 miles of fuel left, the gauge still reads a little under a 1/4. On the way to Barber my first stop came at 160 miles. The light had been on for about 20 miles and it took 3.4 gallons. I had been cruising at 75 to 80 with maybe 40 pounds of gear.
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I think you are thinking Imperial gallons. The tanks hold 5.3 U.S. gallons which converts to 4.2 Imperial gallons. You were probably reading a post by someone in the U.K. or Canada.
My bikes are '92 and '94 models. All of them hold 5.3 gallons. I also get a consistant 180 miles on four gallons, and the low fuel light comes on at about 190 miles. These numbers are with the flapper removed.
that is about what i get too on my 94 K75S. consistently get 48-50mpg. mostly sporty backroads riding with a little slab to get to them. on a track day though...got 21mpg for some reason...;-)
the more modern bike, K1300S, gets 46-48mpg.
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that is about what i get too on my 94 K75S. consistently get 48-50mpg.
Same here on a naked '95.
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I'm getting about the same on a naked K75, even having fitted K1100 injectors with higher flow rate.
(http://badges.fuelly.com/images/sig-us/141829.png) (http://www.fuelly.com/motorcycle/bmw/k75c/1987/rbm/141829)
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I class myself as a "conservative rider." No excessive speed, no jack-rabbit starts, so I can't understand why my MPG is low, as compared to youse guys. Then, there is the issue with the low fuel idiot light. I do not have a gas gauge--it's just a plain ole K75 with OEM side bags. Oh, yeah, I added a small, aftermarket trunk, but my body blocks the wind going to it, so I've got to look some other places. Incidentally, my R1100RT gets much better MPG than the K75 and I do ride the R1100 fairly aggressively.
There is also the chance that my perception of gas volume remaining in my tank is in error. Can anyone tell me in inches how far up the RH side of the tank one gallon of gas would measure? (With bike on center stand)
Four gallons is probably tops at a fill up with mileage varying from 145-160.
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Whitedog, get a two liter bottle and fill it with gas and put it in your top case and go ride the bike until it runs out of gas. Put the two liters in the tank and go fill it at the nearest gas station. With luck you won't have to go to far to get gas. Add 1/2 gallon to what you put in and that will be approximately what your tank holds.
As far as mileage, what do your spark plugs look like? It sounds like you have a rich mixture, possibly caused by a funky engine temperature sensor.
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So I can conclude I have about 1/2 gallon in the tank when the pump quits pumping? Edging closer to that 5.2 gallon tank.
I have not examined the plugs. Based on paperwork that came with the bike, a previous owner went thru the bike at 22K miles, doing replacements and/or maintenance, assuming the speedo is the OEM. I have something in excess of 31K now, so my assumption are the plugs are good. But, I'll look at them.
Where is the engine temperature sensor located and how would I test it for proper function?
Maybe you get a better grade of gas than I do. All our gas in NC comes thru the Colonial Pipeline from Louisiana area. Have no idea if ethanol is added there or here. I've heard of some truck tankers using the "slosh method" for fuel additives. I've been paying for 100% gas now for about a year in both Beemers. My Honda cycles run fine on 10% ethanol regular.
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I class myself as a "conservative rider." No excessive speed, no jack-rabbit starts... Incidentally, my R1100RT gets much better MPG than the K75 and I do ride the R1100 fairly aggressively.
Probably more of a correlation than an incidental anomaly.. try flogging the K for a few tanks and see if the mpg's don't go up.
As backward as it seems, there is a linear relationship between the tach and the mpg.
3K's = 30's mpg
4K's = 40's mpg
5k's = 50's mpg (appropriate yeehaa levels also obtained in this range)
Nothing about my riding style is in the interest of saving fuel or tires for that matter, but I get 50-55mpg consistently, mostly running 97 Chevron lately at about 10-15 gal per week.
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As backward as it seems, there is a linear relationship between the tach and the mpg.
3K's = 30's mpg
4K's = 40's mpg
5k's = 50's mpg (appropriate yeehaa levels also obtained in this range)
When I ride at 65mph-75mph for long distances, the mpg rate is at or below the low end of my scale.
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When I ride at 65mph-75mph for long distances, the mpg rate is at or below the low end of my scale.
Well, you either lack a wind screen, or your moto leaks fuel at high speeds. :giggles
Actually, I would agree with you Laitch. I get my best mpg during everyday, short 10-20 mile trips, stop and go, up and down through 4 (mostly 3) gears. Technique I picked up here at the world famous motobrick.com
I used to cruise around in overdrive thinking 40mpg was amazing. Dropped 5th gear, gained 10mpg... go figure.
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I get my best mpg during everyday, short 10-20 mile trips, stop and go, up and down through 4 (mostly 3) gears. Technique I picked up here at the world famous motobrick.com
It's not the duration of the trips, it's the speed during them. Over 65mph the mpg drops by 5% or so.
To clarify, it isn't that I lack a windscreen, Brick. I prefer riding without one. I like the sound of bird, insect and debris impacts on my riding jacket and helmet. Riding in a swarm of locusts or love bugs is challenging; however, bug gore congealing on gear is a badge of honor. :yes
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...bug gore congealing on gear is a badge of honor. :yes
Not to mention a significant source of protein during the interminable Vermont winter.
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Not to mention a significant source of protein during the interminable Vermont winter.
:hehehe I peel it off, dry it and sell it as jerky at the winter farmers market.
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As far as MPG, I get a consistent 45mpg at engine speeds up to 5000rpm above that it begins to drop to a fairly consistent 38-40mpg at engine speeds above 6500rpm in 5th gear. This is true on both of my K75's, the RT with a barn door fairing/windshield as well as the K75S which is nearly naked with a cut down windshield.
Whitedog, you do not have 1/2 gallon of gas in the tank when it runs out of gas, the tank is EMPTY as in "there is no gas at all in it". The half gallon I mentioned is the gas from the two liter bottle that you put in so you could get to a gas station after you ran the tank dry.
I have to go now before my head explodes.
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I have to go now before my head explodes.
Are you sure?
A video of that will get a lot of YouTube hits and might even pay for quite a few Techron treatments.
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I just ran 122 miles and almost never got above 3rd gear. Some 4th. RPM up to 7K+ and mph avg. 60 to 90 mph.on mostly rural highways. 38+mpg is what I got.
I rode with a friend from work this Summer that has a Honda exciter or rebel, 250CC bike so I drove like your Grandma. My MPG was 52+mpg. Lots of 5th and not much throttle.
MY average is 42+mpg at my normal driving speeds and gear selection. Commuting and just above speed limit travel on rural roads. Through towns n highway speeds 55 to 70.
I don't run enough ethyl gas to know how it affects my gas mileage,(the original thread theme). But I swear that when I put the high test ethyl in (93 octane) Greta runs better. But my brain won't accept that, so I stick to 91 octane non-ethtyl. If you can trust the suppliers and the "independent" agents of non-ethyl gas. Of which I am always suspicious, my paranoid nature, and the integrity of the tanks supplying the fuel from these older independent fuel retailers.............................Prolly another thread in that query/statement? :dunno
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Oh, Mighty Gryphon, hold onto your head. I'll be sure to post my tank capacity but it will be several weeks before I know.
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My home gas station from 2008.
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I get the best mpg on the '05 K12LT ~ 45, the 91' K100RS 4V yields ~ 40 (and I ride it most aggressively) and the '85 K100 Standard (no shield) is ~ 38. I feel like a sail on the '85 with it's upright seating position. My weekly route is the same for all bikes, I'm primarily a commuter, and I run Shell or Chevron Premium. I used to run Regular in the '02 K12LT as it started better on Regular when it was winter - not that we get much of one here in Alabama the Beautiful, but I worked Second shift and would get on to go home between 10 pm and 2 am. My rule was, if it were above 40 degrees when I left home at 1 pm, I would ride. It might be below freezing when I left work for home (heated vest are NICE! and the heated seat doesn't hurt either =-}). The '05 K12LT doesn't seem to have the same issue but I no longer work Second shift to know.
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Maybe you need to go on a diet or something. Lose some weight maybe. I dunno. :hehehe