Gas Mileage Seems Low


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DougEFresh1123
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Motorcycle: 2002 Honda Magna VF750
1994 Honda Goldwing 1500SE

Gas Mileage Seems Low

Post by DougEFresh1123 » Mon Sep 24, 2018 2:38 pm



I filled up my fuel tank for the second time after purchase so I was able to calculate my MPG and now I have some concerns regarding the mileage. According to my friend that I bought the bike from he says when the low fuel light turns on there is a gallon of gas left and he is good for 35 miles. Well my low fuel light went on the other day and I did about 10 miles before re-filling the tank. I put in 5.653 gallons and had 160.3 miles on the trip odometer, this calculates out to 28.36 MPG, which seems low to me.

I know I have been having a difficult time getting the idle to rest at 800 RPMs when the engine is warm, she idles at around 1200 or so. I'l get it adjusted for a day or two but then it jumps back up. I can't imagine this high idle is chewing up almost 7 MPG especially since I'm not idling for extended times. I do realize I am driving in city traffic (but not stop and go just a lot of lights and stop signs) and my mileage may not be at 35 but I would have estimated closer to 32-33 MPG.

i don't think I have a heavy throttle hand but maybe I do. Any help you can provide is greatly appreciated.

Thanks - Doug


'02 Magna VF750
'96 GL1500SE
- Doug

“We must reject the idea that every time a law's broken, society is guilty rather than the lawbreaker. It is time to restore the American precept that each individual is accountable for his actions.”
― Ronald Reagan

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virgilmobile
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Re: Gas Mileage Seems Low

Post by virgilmobile » Mon Sep 24, 2018 3:37 pm

If your "choke"does not completely return to the off position at the carbs(regardless of the lever position) it will cause poor idle(loping)and excessive fuel consumption.You would have to look at the actual part on the carb to verify that they are closed.Mine did stick open just a touch due to the linkage binding and sticking levers.
Just a thought and cheap to check.

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bluthundr31
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Re: Gas Mileage Seems Low

Post by bluthundr31 » Mon Sep 24, 2018 4:04 pm

I've found that using a proper mixture of Seafoam for a few tank-fulls of gas will "miraculously" clean out those pesky Idle jets and your idle will smooth out. Try to stay below, or at, 2k RPM when riding in town because anything over 2k bypasses the idle jets. It will NOT resolve the idle issue overnight, , , but ,religious use of a seafoam mixture for half-a-dozen tank fulls will clean 'er up nicely. Continue playing with the idle adjusting knob, but it'll smooth out soon. I experienced the exact issue with my surging idle causing similar mileage as yours, , , , , SEAFOAM WAS THE SOLUTION!!! I'm consistently getting mid 30's now. I attribute many of the carb/gas troubles with these beasts on the crap corn additives in all the gas. They are NOT intended to run on corn!!!

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DougEFresh1123
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1994 Honda Goldwing 1500SE

Re: Gas Mileage Seems Low

Post by DougEFresh1123 » Mon Sep 24, 2018 4:07 pm

virgilmobile wrote:
Mon Sep 24, 2018 3:37 pm
If your "choke"does not completely return to the off position at the carbs(regardless of the lever position) it will cause poor idle(loping)and excessive fuel consumption.You would have to look at the actual part on the carb to verify that they are closed.Mine did stick open just a touch due to the linkage binding and sticking levers.
Just a thought and cheap to check.
Thank you!
'02 Magna VF750
'96 GL1500SE
- Doug

“We must reject the idea that every time a law's broken, society is guilty rather than the lawbreaker. It is time to restore the American precept that each individual is accountable for his actions.”
― Ronald Reagan

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DougEFresh1123
Posts: 39
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1994 Honda Goldwing 1500SE

Re: Gas Mileage Seems Low

Post by DougEFresh1123 » Mon Sep 24, 2018 4:10 pm

bluthundr31 wrote:
Mon Sep 24, 2018 4:04 pm
I've found that using a proper mixture of Seafoam for a few tank-fulls of gas will "miraculously" clean out those pesky Idle jets and your idle will smooth out. Try to stay below, or at, 2k RPM when riding in town because anything over 2k bypasses the idle jets. It will NOT resolve the idle issue overnight, , , but ,religious use of a seafoam mixture for half-a-dozen tank fulls will clean 'er up nicely. Continue playing with the idle adjusting knob, but it'll smooth out soon. I experienced the exact issue with my surging idle causing similar mileage as yours, , , , , SEAFOAM WAS THE SOLUTION!!! I'm consistently getting mid 30's now. I attribute many of the carb/gas troubles with these beasts on the crap corn additives in all the gas. They are NOT intended to run on corn!!!
And why didn't I think of this simple solution first? :?: Damn, I think I used my last can of Seafoam in the car. Gives me an excuse to go to a Farm & Fleet they seem to have the best prices on Seafoam.
'02 Magna VF750
'96 GL1500SE
- Doug

“We must reject the idea that every time a law's broken, society is guilty rather than the lawbreaker. It is time to restore the American precept that each individual is accountable for his actions.”
― Ronald Reagan

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AZgl1800
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Re: Gas Mileage Seems Low

Post by AZgl1800 » Mon Sep 24, 2018 6:29 pm

a single tank of gas is not an accurate basis for computer MPG.

different gas pumps do not give equal volumes of gas for the same exact digital meter reading.

also, it is impossible to get the tank full to the "same exact point" no matter how hard you try.

MPG is effected by so many variables it is difficult to even come close to an accurate value.
I have a spreadsheet that I made for my '98SE that covers 5,000 miles with the overall average of 33.3 mpg with the same Tulsa Tall windshield on it the whole time.

that covers dinky little grocery store trips, medium range 15-30 mile trips, cross country runs that ran out the fuel tank several times thru the day.... and that spreadsheet shows MPG readings as low as 22 mpg, to a high of 40 mpg.

day in, and day out, when I was driving to work and back, a 17 mile trip one way, on a freeway for 15 miles of that, at 40 to 80 mph hot dog go to work, get home runs.... that always produced 29-31 mpg.

that same bike, hit the interstate at 85 mph until the tank goes dry, gets 26-28 mpg.
that same bike, go look at the fall color with friends, will get 40-45 mpg.

it all depends on the throttle hand, the headwinds, the terrain......
"It is, what it is".....

oh, the low fuel light, IF, you just happened to catch it just as it starts to glow ( which is very dim ), there will be 1.1 gallon of fuel remaining in the tank. so, 1x33 mpg average gives you 30 miles safely to the next gas station.
~John

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DougEFresh1123
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1994 Honda Goldwing 1500SE

Re: Gas Mileage Seems Low

Post by DougEFresh1123 » Tue Sep 25, 2018 9:22 am

AZgl1800 wrote:
Mon Sep 24, 2018 6:29 pm
a single tank of gas is not an accurate basis for computer MPG.

different gas pumps do not give equal volumes of gas for the same exact digital meter reading.

also, it is impossible to get the tank full to the "same exact point" no matter how hard you try.

MPG is effected by so many variables it is difficult to even come close to an accurate value.
I have a spreadsheet that I made for my '98SE that covers 5,000 miles with the overall average of 33.3 mpg with the same Tulsa Tall windshield on it the whole time.

that covers dinky little grocery store trips, medium range 15-30 mile trips, cross country runs that ran out the fuel tank several times thru the day.... and that spreadsheet shows MPG readings as low as 22 mpg, to a high of 40 mpg.

day in, and day out, when I was driving to work and back, a 17 mile trip one way, on a freeway for 15 miles of that, at 40 to 80 mph hot dog go to work, get home runs.... that always produced 29-31 mpg.

that same bike, hit the interstate at 85 mph until the tank goes dry, gets 26-28 mpg.
that same bike, go look at the fall color with friends, will get 40-45 mpg.

it all depends on the throttle hand, the headwinds, the terrain......
"It is, what it is".....

oh, the low fuel light, IF, you just happened to catch it just as it starts to glow ( which is very dim ), there will be 1.1 gallon of fuel remaining in the tank. so, 1x33 mpg average gives you 30 miles safely to the next gas station.
Thanks AZ.

I've gotten pretty good with getting the tanks on my motorcycles filled to about the same level. Yes I may have a little more or less than previous times but not enough to really skew the MPG calculations.

I'll start to utilize your spreadsheet for both my bikes (2002 Honda Magna). Guess I will just have to give it some time and really get to know the bike. My biggest fear is running out of gas while out on a trip and being miles from the nearest station.

Once I get comfortable on the wing she will become more of the weekend warrior road trip bike and the Magna will be back to being the daily bike.
'02 Magna VF750
'96 GL1500SE
- Doug

“We must reject the idea that every time a law's broken, society is guilty rather than the lawbreaker. It is time to restore the American precept that each individual is accountable for his actions.”
― Ronald Reagan

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dingdong
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Re: Gas Mileage Seems Low

Post by dingdong » Tue Sep 25, 2018 10:04 am

It might be better to wait a few weeks before calculating mileage. New to you bike. Don't tell us you haven't been twisting the throttle just to test her out. :D
Tom

John F. Kennedy would be impeached by todays liberal Democratic socialist party.

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DougEFresh1123
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Re: Gas Mileage Seems Low

Post by DougEFresh1123 » Tue Sep 25, 2018 10:27 am

dingdong wrote:
Tue Sep 25, 2018 10:04 am
It might be better to wait a few weeks before calculating mileage. New to you bike. Don't tell us you haven't been twisting the throttle just to test her out. :D
I've been giving her some throttle but nothing compared to how I ride the Magna. I'm still trying to get used to getting up and off the line without being all herky-jerky and redlining. I'm so used to a 9500 redline and this 5500 is killing me. :lol:
'02 Magna VF750
'96 GL1500SE
- Doug

“We must reject the idea that every time a law's broken, society is guilty rather than the lawbreaker. It is time to restore the American precept that each individual is accountable for his actions.”
― Ronald Reagan

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bellboy40
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Re: Gas Mileage Seems Low

Post by bellboy40 » Tue Sep 25, 2018 11:10 am

DougEFresh1123 wrote:
Tue Sep 25, 2018 10:27 am
I've been giving her some throttle but nothing compared to how I ride the Magna. I'm still trying to get used to getting up and off the line without being all herky-jerky and redlining. I'm so used to a 9500 redline and this 5500 is killing me. :lol:
I think I see why your gas mileage is suffering! :lol:

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DougEFresh1123
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Re: Gas Mileage Seems Low

Post by DougEFresh1123 » Tue Sep 25, 2018 11:21 am

bellboy40 wrote:
Tue Sep 25, 2018 11:10 am
DougEFresh1123 wrote:
Tue Sep 25, 2018 10:27 am
I've been giving her some throttle but nothing compared to how I ride the Magna. I'm still trying to get used to getting up and off the line without being all herky-jerky and redlining. I'm so used to a 9500 redline and this 5500 is killing me. :lol:
I think I see why your gas mileage is suffering! :lol:
That could be the issue, not smooth enough on the starts so the front end is bouncing up and down. A little scary as the front end starts to dive down and then lift up, feel like I'm about to get thrown off the back. :lol:
'02 Magna VF750
'96 GL1500SE
- Doug

“We must reject the idea that every time a law's broken, society is guilty rather than the lawbreaker. It is time to restore the American precept that each individual is accountable for his actions.”
― Ronald Reagan

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dingdong
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Re: Gas Mileage Seems Low

Post by dingdong » Tue Sep 25, 2018 2:56 pm

Your 1500 should be just as smooth off the line as any other bike. I suspect you have a carb problem. This could be the reason for the suspected low mileage.
Tom

John F. Kennedy would be impeached by todays liberal Democratic socialist party.

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DougEFresh1123
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Re: Gas Mileage Seems Low

Post by DougEFresh1123 » Tue Sep 25, 2018 4:18 pm

dingdong wrote:
Tue Sep 25, 2018 2:56 pm
Your 1500 should be just as smooth off the line as any other bike. I suspect you have a carb problem. This could be the reason for the suspected low mileage.
I do have some Seafoam in there for now, and will continue to run some for the rest of my riding season, but am beginning to suspect I will need to have the carbs pulled and cleaned. I'm definitely not starting smoothly and yes it does seem to bog down a bit at around 2500 rpms and then pick up move.
'02 Magna VF750
'96 GL1500SE
- Doug

“We must reject the idea that every time a law's broken, society is guilty rather than the lawbreaker. It is time to restore the American precept that each individual is accountable for his actions.”
― Ronald Reagan

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ct1500
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Re: Gas Mileage Seems Low

Post by ct1500 » Tue Sep 25, 2018 7:38 pm

DougEFresh1123 wrote:
Mon Sep 24, 2018 2:38 pm
this calculates out to 28.36 MPG, which seems low to me. I know I have been having a difficult time getting the idle to rest at 800 RPMs when the engine is warm, she idles at around 1200 or so. I'l get it adjusted for a day or two but then it jumps back up. I can't imagine this high idle is chewing up almost 7 MPG especially since I'm not idling for extended times. I do realize I am driving in city traffic (but not stop and go just a lot of lights and stop signs) and my mileage may not be at 35 but I would have estimated closer to 32-33 MPG.Thanks - Doug
36-42MPG all day long for most 1500's is the norm. You have carb/tuning/plug wire issues as evidenced by the constant need to adjust idle.
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Re: Gas Mileage Seems Low

Post by FM-USA » Wed Sep 26, 2018 8:26 am

Our 1500's are 18+ years old. Age dries out rubber & plastic parts. Heat speeds up this process and they become brittle and shrink. If you have a crack show up in one area, take it for granted more will show up elsewhere.

Poor mpgs has many reasons, personal throttle use, vac leaks, fuel leaks, fuel type & quality, and more.

My poor mpg experiences on my 91 Wing has been vac leaks. 3 times I looked with large & tiny inspection mirrors, found one. A small vac line elbow had become soft & a pinhole BARELY showed. Mpgs went up but 42-44mpg for me wasn't good enough.
When I pulled the carbs I found a larger vac hose had the same issue. Patched it up and now can achieve 48 to 50mpgs riding 1 & 2 up. A couple times riding 2 up I hit 52mpgs.

Another time a dragging brake hurt mpgs. Brake piston jambed and wouldn't return.

I found a way to repeatedly fill the tank consistently to the same place and only have a variable of about 1 ounce.
Set the bike on the centerstand. Look inside the filler neck and you'll see a 1/8" hole. Fill until the tiny air bubbles stop coming out that hole. IF you have an issue filling that full due to fuel expansion, stop filling when the fuel touches the filler neck.

More speed equals more headwind. Headwind hurts mpgs.
Rev. Jim was told when asking what a yellow light means,...SLOW DOWN. Try slowing down a bit to a consistent max speed. On my Wing 2850 rpms seems to be a magical number for mpgs. I try to stay under it.

HOPE THIS HELPS

.
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DougEFresh1123
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1994 Honda Goldwing 1500SE

Re: Gas Mileage Seems Low

Post by DougEFresh1123 » Wed Sep 26, 2018 8:43 am

ct1500 wrote:
Tue Sep 25, 2018 7:38 pm
DougEFresh1123 wrote:
Mon Sep 24, 2018 2:38 pm
this calculates out to 28.36 MPG, which seems low to me. I know I have been having a difficult time getting the idle to rest at 800 RPMs when the engine is warm, she idles at around 1200 or so. I'l get it adjusted for a day or two but then it jumps back up. I can't imagine this high idle is chewing up almost 7 MPG especially since I'm not idling for extended times. I do realize I am driving in city traffic (but not stop and go just a lot of lights and stop signs) and my mileage may not be at 35 but I would have estimated closer to 32-33 MPG.Thanks - Doug
36-42MPG all day long for most 1500's is the norm. You have carb/tuning/plug wire issues as evidenced by the constant need to adjust idle.
Thank you CT!
My plan was already to change plugs, fuel filter and air filter(s) during the winter months, now I'll add pulling the carbs and checking hoses and wires.

Doug
'02 Magna VF750
'96 GL1500SE
- Doug

“We must reject the idea that every time a law's broken, society is guilty rather than the lawbreaker. It is time to restore the American precept that each individual is accountable for his actions.”
― Ronald Reagan

User avatar
DougEFresh1123
Posts: 39
Joined: Mon Aug 27, 2018 10:22 am
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1994 Honda Goldwing 1500SE

Re: Gas Mileage Seems Low

Post by DougEFresh1123 » Wed Sep 26, 2018 9:08 am

FM-USA wrote:
Wed Sep 26, 2018 8:26 am
Our 1500's are 18+ years old. Age dries out rubber & plastic parts. Heat speeds up this process and they become brittle and shrink. If you have a crack show up in one area, take it for granted more will show up elsewhere.

Poor mpgs has many reasons, personal throttle use, vac leaks, fuel leaks, fuel type & quality, and more.

My poor mpg experiences on my 91 Wing has been vac leaks. 3 times I looked with large & tiny inspection mirrors, found one. A small vac line elbow had become soft & a pinhole BARELY showed. Mpgs went up but 42-44mpg for me wasn't good enough.
When I pulled the carbs I found a larger vac hose had the same issue. Patched it up and now can achieve 48 to 50mpgs riding 1 & 2 up. A couple times riding 2 up I hit 52mpgs.

Another time a dragging brake hurt mpgs. Brake piston jambed and wouldn't return.

I found a way to repeatedly fill the tank consistently to the same place and only have a variable of about 1 ounce.
Set the bike on the centerstand. Look inside the filler neck and you'll see a 1/8" hole. Fill until the tiny air bubbles stop coming out that hole. IF you have an issue filling that full due to fuel expansion, stop filling when the fuel touches the filler neck.

More speed equals more headwind. Headwind hurts mpgs.
Rev. Jim was told when asking what a yellow light means,...SLOW DOWN. Try slowing down a bit to a consistent max speed. On my Wing 2850 rpms seems to be a magical number for mpgs. I try to stay under it.

HOPE THIS HELPS

.
Thank you!

I have gotten pretty good with being consistent with my fuel fill ups on my 2002 Magna and I am using the same process. I stay on the bike keeping it vertical and fill it up until it just comes into the filler neck. Plan on using this process on the Wing, I will add looking for the hole and watching the bubbles.

Right now all of the driving has been 20 mile round trips to and from the office. The majority of the miles are speed limit of 25-40, so i'm usually doing from 30 - 45. Not a lot of fast speeds to eat up the fuel. I know I need to work on my throttle control/response and ideal rpm for changing gears for the Wing it so much different than the Magna. Right now I am trying to change at around 2000 to 2200 rpms.

Over the winter I will be be changing fuel and air filters, spark plugs, and checking the plug wires. That's as good as a time as any to check the various hoses for leaks. I will also be pulling the carbs and giving them a good cleaning.

Guess it is time to find a decent size Ultra Sonic carb cleaner and the appropriate solutions. Since I will have the carbs for the Wing and the Magna out for service over the winter.

Doug
'02 Magna VF750
'96 GL1500SE
- Doug

“We must reject the idea that every time a law's broken, society is guilty rather than the lawbreaker. It is time to restore the American precept that each individual is accountable for his actions.”
― Ronald Reagan

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AZgl1800
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Re: Gas Mileage Seems Low

Post by AZgl1800 » Wed Sep 26, 2018 10:34 pm

DougEFresh1123 wrote:
Tue Sep 25, 2018 9:22 am
I'll start to utilize your spreadsheet for both my bikes (2002 Honda Magna). Guess I will just have to give it some time and really get to know the bike. My biggest fear is running out of gas while out on a trip and being miles from the nearest station.

hope the spreadsheet works out for you.

I carry a heavy duty, plastic jerry can that just exactly fits the right saddle bag, holds 1 gallon.
Been there for 2 years now, need to pour it in the lawn tractor tomorrow, and fill it with fresh gas.
it is Pure Gas..... my Emergency Standby genset has the same E-0 non-ethanol gas in it, been there for 2-1/2 years.

got it out this week to see if that stuff had jelled up? ( Stabil is in the gas )
nope, opened the tank gas valve, closed the choke, hit the start button, and it fired up on the 2nd revolution. let it run at full rpm for an hour.

Need to make it a habit to exercise that thing once a month. it is for the house in case the power lines go down.... made a special cable for it to plug into the Transfer Panel on the side of the house.


~John

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