Lower fuel milage


Information and questions on GL1500 Goldwings (1988-2000)
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guybguy
Posts: 5
Joined: Sun May 30, 2010 1:50 pm
Location: bakersfield, ca
Motorcycle: 1992 Gl1500

Lower fuel milage

Postby guybguy » Tue Apr 01, 2014 9:59 am



I was wondering if anyone has any thought about my loss of fuel mileage. I have a 92 GL1500 with just over 96,000 miles and have recently replaced the spark plugs, front and rear tires, both sub air filters and use a K&N air filter. However, I was getting 41-43 MPG highway and 36-38 around town, but even with these items done I'm have dropped down to around 36 MPG on the road and just had staggering drop to 28 MPG in town. This is done 1 up and my driving habits have not changed, have any of you experienced this as it is very frustrating to me. Also, I have changed out my alternator to the Compu-Fire and since I have my radio doesn't stay "tuned" in so to speak where the station is not a constant clear sound anymore its there but I can hear it come and go not all the way but just not as sharp anymore. Thanks for any input on my problems.



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ct1500
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Re: Lower fuel milage

Postby ct1500 » Tue Apr 01, 2014 4:37 pm

Did the drop start right at the plug change or did you do the plugs feeling something different was going on with the bike.

Regarding the radio noise, the OEM alternator has a radio noise suppressor attached I forget if the Compufire comes with one or not.
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bridan
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Joined: Sat Mar 08, 2014 7:52 am
Location: lebanon, Maine
Motorcycle: 1990GL1500
Aspencade"

Re: Lower fuel milage

Postby bridan » Wed Apr 02, 2014 6:18 pm

I'm having the same problem I have a 1990 GL 1500 aspencade only getting 150 a tank full. just got it back from the dealer and gave it a complete tune up.. also tech is at 3 when I'm doing 65 mph

guybguy
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Location: bakersfield, ca
Motorcycle: 1992 Gl1500

Re: Lower fuel milage

Postby guybguy » Thu Apr 03, 2014 7:25 am

I changed out the plugs as I thought it might help as I had about 8,000 miles on them, but the loss seems to have occured pretty quickly within the last year or less. And, like the other post I too will only get about 150 miles per tank now.

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robb
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Re: Lower fuel milage

Postby robb » Thu Apr 03, 2014 8:48 am

Is there a chance you are running any E85 fuel, 15% mix. Might want to look on http://www.buyrealgas.com/ and see if real gas makes a difference. Any chance a plug wire not crossed or not completely on. Check the fuel filter, restricted robs power and waste fuel. Did you gap plugs or leave as they came.

When I installed the high output alternator there was a note to use the noise suppressor on the stock unit. Radio sounds great.

Check the speedo against a GPS for accuracy, might be riding farther than it's reading. Tested a friends 88 and at 100 miles the GPS was showing 83. Gear in front axle was eat up.

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ct1500
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Re: Lower fuel milage

Postby ct1500 » Thu Apr 03, 2014 8:40 pm

guybguy wrote:I changed out the plugs as I thought it might help as I had about 8,000 miles on them, but the loss seems to have occured pretty quickly within the last year or less. And, like the other post I too will only get about 150 miles per tank now.


Brakes are not dragging?

One thing easily checked is the vacuum fuel valve, in some instances it can allow fuel to be drawn directly into intake via the vacuum hose. Remove vacuum hose while running and check for any wetness out of valve or hose. A vacuum pump on valve to check its holding ability would be best.

At 97k you are getting up there and a vacuum hose/vacuum valve problem could be the reason and unfortunately are not all easily checked especially the known one under carbs that goes to ECM and will control ign timing. Vacuum leaks leave a distinctive albeit subtle putt-putting sound out the tailpipes at idle.

Some bikes are so lean at idle that a richening of pilots will actually increase MPG's. One other item to check just for kicks would be coolant level under RADIATOR cap not reserve when cold, should be up close to top. A quick check of engine systems is to lower idle speed until it stalls, a well tuned bike should be able to go down to 450 RPM or thereabouts before stalling at normal operating temp and on center stand.

Put the cardboard across the front as directed here and note any RPM changes.

viewtopic.php?f=14&t=17014
Last edited by ct1500 on Thu Apr 03, 2014 9:12 pm, edited 1 time in total.
This is what I do
Local and need repair help with your 1500, Valkyrie or ST please PM

guybguy
Posts: 5
Joined: Sun May 30, 2010 1:50 pm
Location: bakersfield, ca
Motorcycle: 1992 Gl1500

Re: Lower fuel milage

Postby guybguy » Thu Apr 03, 2014 9:02 pm

I do have a new fuel filter as well forgot to add in the original post I believe I do have that putt putt sound and a strong smell of exhaust fumes as if not all burned, so will look at those things. Also, will need to check the paperwork that came with the alternator, but do not recall anything about the noise suppressor hopefully that's the correction.

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ct1500
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Re: Lower fuel milage

Postby ct1500 » Thu Apr 03, 2014 9:16 pm

What was the color of the old plugs that came out. Stronger than previous exhaust smell would indicate rich, the cardboard trick will alert you which way.

If the performance is down could also be a carb vacuum piston acting up, check by cracking throttle hard and fast while looking down carb throats. You want to see them both moving in tandem.
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Local and need repair help with your 1500, Valkyrie or ST please PM

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ct1500
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Re: Lower fuel milage

Postby ct1500 » Fri Apr 04, 2014 7:39 am

Ever smell gasoline around bike, not that the fuel leak alone would cause such a drop but on an older ride 2 or 3 of the usual suspects when combined will.

If everything is OK with the most likely then the search continues with the more esoteric causes such as Ta & Tw sensors, AJC's, Shot air, gearshift sensor, etc. etc.

It is always a good idea to confirm odometer accuracy first.
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rescue1042
Posts: 128
Joined: Tue Jun 22, 2010 7:17 pm
Location: Hutchinson Mn
Motorcycle: 1982 honda goldwing interstate
1998 honda 1500 SE
2002 honda Gl1800

Re: Lower fuel milage

Postby rescue1042 » Tue Apr 08, 2014 7:43 am

I was having same prob so iam pretty sure the problem iam having is the slide stuck ordered new one and will install and hope that's the trick will let ya all know, just something to check( I put a couple pics up you can look at and see if you have problem
2002 GL1800
I dont always ride!
But when i do it's on a Goldwing!!

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robb
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Re: Lower fuel milage

Postby robb » Tue Apr 08, 2014 8:45 am

Might try running some Seafoam through the fuel system. Contrary to some, I add about 1 oz Marvel Mystery Oil per gallon of fuel. Due to health issues bike may set for weeks before riding, and it has not let me down.

guybguy
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Re: Lower fuel milage

Postby guybguy » Tue Apr 08, 2014 12:00 pm

Haven't heard of that product before "SeaFoam" where can I get it and what's its purpose.

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robb
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Motorcycle: 1989 Honda GL1500 Aspencade

Re: Lower fuel milage

Postby robb » Tue Apr 08, 2014 12:33 pm

Sea Foam® Motor Treatment for Gas and Diesel Engines is a 100% pure petroleum product that works instantly to clean deposits from internal engine parts and remove moisture from oil crankcases and fuel tanks.
http://shop.advanceautoparts.com/p/sea- ... /6410004-P

http://www.walmart.com/ip/Sea-Foam-Moto ... z/16664932

guybguy
Posts: 5
Joined: Sun May 30, 2010 1:50 pm
Location: bakersfield, ca
Motorcycle: 1992 Gl1500

Re: Lower fuel milage

Postby guybguy » Tue Apr 08, 2014 1:37 pm

Thank you for all of the help. Will start with the basics then go from there.

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rescue1042
Posts: 128
Joined: Tue Jun 22, 2010 7:17 pm
Location: Hutchinson Mn
Motorcycle: 1982 honda goldwing interstate
1998 honda 1500 SE
2002 honda Gl1800

Re: Lower fuel milage

Postby rescue1042 » Wed Apr 09, 2014 10:23 am

let us know what ya find thanks


2002 GL1800
I dont always ride!
But when i do it's on a Goldwing!!


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