Poor fuel economy, gl1100

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The problem is periodic and sometimes I can pull the trailer into headwinds and get about 35 MPG. But when this occurs I'm only getting 19 or 20 MPG. Ihave owned two 83 Goldwing GL 1100's in the past and put about 350.000 Kms on them, pulled the same trailer over the same roads with the same load in the trailer, under similar conditionsand never eperienced this problem. The engine sounds like it is starving for.fuelI've had a Honda trained Service man check all systems to make sure everything is is in proper oder as far as the engine is concerned. Timing, Carbs sync'd, timing vac,I check tire pressure every day I ride in both the bike and the trailer. I changed the brake pads between tripswhen it happened and I'msure that there is no brake drag or other brake problems.Two years ago I had to get into first gear to make it up the Creston BC, east bound on highway 3 grade. My wife had to get off and catch a ride with another rider to make it to the top of the hill. The next day the darn thing ran like a top ??? Same weather and temp conditions. Both other 83 GL 1100's I had pulled the same trailer up ther same hills many times no problem.

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Do you notice any abnormal exhaust when this happens? Sure doesn't sound like fuel starvation with the mileage dropping so much.

Do you have to shut down and restart later on to get rid of the problem or does it just clear up on it's own.

Will shutting downfor a few minutes get rid of it?

Heat related?

Any chance there's a fuel leak between the carbs and fuel pump, might try flexing things around in this area.

Tried taking off the fuel filler cap when it happens?

If you think it's fuel starvation, what happens when you put the choke on during an occurance?

Really not enough data to make a good guess yet.

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The problem seems to be random Only happens pulling the trailer into head winds but not every time.Ive rodeinto somevery strong headwinds,pulling the trailer and got great mpg and no slow speeds. I've tried choke use to varying amounts dosen't seem to change it, untill it's choked too much, then it seems to shut down.I've tried wiggling the fuel filter and lines whenthishappensand no change. Shutting it off fora few munuets makes no change. one time I parked overnight and the next day it continued. I coaxed ity home, about 200 miles. then a couple of days later I went for a ride no trailer and it gave me 40 mpg. Ive tried fuel cap off, Air filter out.when it acts like this, and no change. It sounds like its really underpowered when it acts like this,as I've said sounds like its starving for fuel. Pulled the sparkplugs they look nice and amber like they should, put in new plugs still acts the same. Has never done it when I'm not pulling the trailer even pushing unbelievable headwinds on the prairies.

When it runs like this the best I can get for top speed in 4th or 5th gear is 90 KPH which is about 55 MPH. Thanks in advance, Ben

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Put a voltmeter on battery and ride. Youll probably find its electrics, not fuel. The spark plugs should be almost white when engine is ticking off perfectly, any dark color except for a light orange or yellow (unleaded petrol deposits)indicates unburned fuel and in-efficient operation. Since the engine generally runs O.K., you dont have any gross failures, but a problem with tuning. Something minor but annoying.

When I began researching the GL1200s in the early 1990's, I noticed a variance in electrical system voltage that corresponded with relative humidity in excess of about 60%. Above that figger, the charging would go whacky and engine start to run poorly. Traced it to bad wiring connections. The bike started running rough idle, backfiring and destroyed the digital clock within 3 months. The bad wiring starved the ignition coils for voltage (they got 6-9 volts instead of 14.5) and it made the engine run poorly.

Ill predict the voltmeter will dip to 13.2V DC minimum and 14.5 max. IT should be 14.5 - 14.8.

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Ben Herr wrote:

I have a digital volt meter (Honda) as part of a digital dash that I purchased from Honda It reads 14.5 to14.7 at all times when the engine is revved over 1000 rpms.

Click to expand...

Thats not good. It must keep that reading down to 400 RPM or so. Run the idle speed down and see if it falls.

Checking volts on the battery is a crude check for charging ability, it proves there are no gross failures like a bad stator or regulator. But, thats not enough to diagnose performance problems. The chronic motorcycle problem, in every Honda Ive owned from 360 - 1200 cc, is lack of voltage to the ignition coils. Thats the critical thing, and unfortunately, next to impossible for most riders to check. could be bad wiring to coils, but without an oscilliscope, cannot verify it.

Due to the intermittient nature, I doubt its fuel system, those bugs are usually constant and increase with time. Im betting on electrics. Yes, the battery sees 14.5 but Ive seen thatwith ignition coils starving for current at the same time. Its not uncommon for the ignition coils to only get 9V when the ignition controller (or breaker points) turn them on, and a Voltmeter cannotmeasure turn-on voltage.

Id do this - remove the power wires from the coils (sorry, my wiring diagram is bad so I cant verify the colors, should be Black/ White) and feed the coils directly from the battery through a 3 amp fuse. May notice a performance increase. If so, bad wiring - I can send you a wiring repair to fix it.


PS I noticed youre in Ontario, is there a correlation between mileage loss and drops in air temperature? Does this loss happen on rides on particularly cold days? Carbs may be out of calibration for very cold weather.

Also- check the rear end and brakes, especially that its pulling a trailer. Trailer puts a lot more load on rear wheel bearings. Lift the wheels and spin them to see if brakes are dragging. Chassis problems can eat up engine power.