GL1500 Tech FAQ


Information and questions on GL1500 Goldwings (1988-2000)
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Solo So Long
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Joined: Thu Mar 26, 2020 4:07 pm
Location: Northern Nevada
Motorcycle: 1999 GL1500 50th Anniversary SE
1989 GL1500 FOR SALE
A pack of Super Cubs
Z50A (pre-headlight)
Formerly (in order):
Honda Super Cub (bought 1968, sold ?)
Kawasaki Coyote (early 1970s)
Honda 350 (mid 1970s)
Kawasaki KZ900-PS (1977)
Honda Super Cubs (various years)
Kawasaki KZ1000C (1978)
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GL1500 Tech FAQ

Post by Solo So Long »



TECH FAQ -- GL1500

JOB ONE -- IMPORTANT!

If you read nothing else, READ THIS!

If you have just bought a GL1500, verify WITH DOCUMENTATION that A), the timing belts have been replaced in the last two years, or B), the belts were replaced within the last 4 years or 50,000 miles (whichever comes first) AND that it has been regularly ridden (1,000 miles or more each year) since the belts were replaced. If either of these is not true, REPLACE THE TIMING BELTS IMMEDIATELY.

"Immediately" in this case means BEFORE you start the engine. The GL1500 (like other Goldwings) has an "interference" engine, meaning that the pistons and valves take up some of the same space at different times during each engine cycle. If a belt fails, the pistons are likely to strike the valves, doing damage significant enough that the engine may need to be replaced!

Honda figures the life of these belts at UP TO 100,000 miles, but that is with the bike being constantly ridden, to keep them supple. If the bike isn't regularly ridden, the belts can take a set, and fail rapidly when the bike is started. A timing belt which is about to fail may look no different than one which was just installed!

Replacing timing belts is a relatively simple job, which the average owner can do with common tools.

viewtopic.php?f=14&t=9774


JOB TWO -- ALSO important!

You need JIS (Japan Industry Standard) screwdrivers to work on your Goldwing. There are NO PHILLIPS SCREWS, so using a Phillips driver WILL result in damaging screw heads. Torx or hex socket head bolts are a suitable replacement for JIS screws in most applications, but if you have the original screws, NOW is the time to buy the JIS driver(s).

They aren't expensive, and can be found on Amazon, so get a set before you start working on your bike.



NEW OWNERS:

Congratulations on your purchase of a 1987 - 2000 Honda Goldwing!

The 4th Generation Goldwing is considered by many riders and owners to be the best series of the family. Made in Marysville, Ohio, a GL1500 shares most features (and parts) with the Honda Valkyrie of the same years. In fact, the Valkyrie was the revival of the "naked" Goldwing. The 500,000th vehicle produced at Marysville was a 1991 Goldwing Apencade, and the millionth Honda motorcycle made in the USA was a 1996 Goldwing Aspencade, showing the importance of the family.

It should also be noted that the most-produced motor vehicle in the world is a relative of the Goldwing -- the Honda Super Cub has been in constant production since 1958, with over 120,000,000 sold! There is some serious history in the Honda clan, and now you have your own small piece of that tradition -- and when you pass a Super Cub, nod your respect to the bike that made your Goldwing possible! No matter the model, you DO meet the nicest people on a Honda!

There were a number of improvements made over the course of GL1500 production, as well as differences in feature packages between the Aspencade (GL1500A), Special Edition (GL1500SE), Interstate (Gl1500I) and Valkyrie (GL1500C) (where the "C" came from, nobody seems to know). This means that, when buying parts, it is important to verify compatibility with your model and year.

The GL1500 was the first 6-cylinger Wing (100 horsepower nominal output), and the only one with twin carburetors, giving it the simplest fuel system in the entire family. The new engine was even more smooth, and thus has won over many riders from V-Twin motorcycles.

Prior to the GL1500, the Goldwing (and, really ALL motorcycle models) was either a "naked" motorcycle or one with saddleboxes and fairing added to a basic design. With the 4th generation, Goldwings evolved into a fully-integrated body on chassis vehicle, weighing a nominal 800 pounds -- which is why the addition of a reverse gear was welcomed by riders.

Under the bodywork (a.k.a "hard candy shell"), a fully-equipped Aspencade or Special Edition will feature such things as cruise control, reverse gear, a stereo radio with intercom and cassette tape deck, integral CB radio, speakers for the passenger, air ride (using a compressor which will also fill tires), cornering lights and very comfortable saddle for both riders. Optional and aftermarket equipment includes windwings, floorboards with heel-toe shifting, armrests and raised footpegs for the passenger, highway floorboards which attach to the engine guards, custom saddles, luggage racks, trailer hitches or receivers, extra lights, extra chrome and numerous add-ons to improve safety, handling or comfort.

Unfortunately for those who bought the Interstate model, this version was made less expensive (and lighter by a few pounds) by eliminating many of the features of the Aspencade and SE -- most notably REVERSE (which can't be added to the Interstate power train). If you are reading this while shopping for a Goldwing, you will probably want to look past the Interstate to a higher model.

In the pecking order, the SE is the top, the Aspencade is upper-mid range, and the Interstate is lower-mid range. NO Goldwing is a bad bike, of any year or model.

With the last of the GL1500s made over two decades ago, it is very rare to find one with low miles. WHO CARES? There are Goldwings with over 250,000 miles on the odometer. GRATUITOUS HARLEY DIG: A Goldwing is barely broken in at the mileage that most Harleys are ever likely to see.



TOPICAL LIST in alphabetical order (kinda)


ANNUAL PREVENTATIVE MAINTENANCE:
There are a few jobs which should be done at the beginning of every year's riding season, no matter how many miles have or have not been ridden the prior year. Of course, you are encouraged to do more to keep your steed happy and healthy, but the basic jobs include:

Brake bleeding / inspection (see: BRAKES and BRAKES: BLEEDING) ALWAYS use DOT 4 brake fluid!
Oil and filter change (see: OIL)
Coolant change / inspection (see: COOLING SYSTEM)
Inspect tires for wear, sun checking (cracks) and date code (see: TIRES)



BRAKES:
The Goldwing weighs around 800 lbs, with a thrust-to-weight ratio of over 1 horsepower to every 8 pounds of empty weight. That's before adding rider(s), luggage and sack lunch. Needless to say, that's a LOT of kinetic energy going down the road, and it needs a lot of braking power to stop.

The GL1500 has disc brakes front and rear, with two hydraulically-operated calipers on the front, one on the rear. The rear caliper and the front-left caliper are linked together, and operated by the brake pedal. This leads to a slightly spongy feel to the pedal, even when freshly bled and filled with new DOT 4 fluid, because the one pedal has to pressurize several times as much line as the normal motorcycle. This can be reduced by using steel-braid-reinforced flex lines.

Highly-trained riders, at this point, will wonder if the linked brakes will affect slow-riding techniques, especially feathering the clutch and rear brake. They generally don't, the techniques are the same, only the tactile feel is different (and rapidly learned).

The brake handle in front of the throttle only operates the caliper on the front-right brake disc. This is also done hydraulically. The master cylinder has a small reservior for fluid, and the sight glass allows easy checking of the fluid level. If fluid is needed, first wipe the outside of the reservoir clean, then use your JIS screwdriver to loosen the screws partway, but do not remove them. At this point, lift the reservoir cap up so that the seal is broken and the cap is loose. Now remove the screws, while keeping the cap from falling. Fill the reservoir, replace the cap, and snug (but do not overtighten) the securing screws.

ALWAYS use DOT 4 brake fluid!



BRAKES -- BLEEDING:
Normal brake flushing and bleeding procedures are like any other bike, except that the front left brake is always bled FIRST, then the rear brake. The hand brake can be bled at any time. ALWAYS use DOT 4 brake fluid!



CLUTCH:
The Goldwing uses a "wet" clutch -- that is, the clutch plates are bathed in oil, to help keep them fron burning up.

This means that the OIL you use is of vital importance. The engine and clutch use the same oil sump, which must be kept at proper level, using oil which meets the JASO MA standard (see: OIL).

The clutch is operated hydraulically, from the lever that is ahead of the left grip on the handlebars. The master cylinder has a small reservior for fluid, and the sight glass allows easy checking of the fluid level. Replacement sight glasses are available, and easily installed.

If fluid is needed, first wipe the outside of the reservoir clean, then use your JIS screwdriver to loosen the screws partway, but do not remove them. At this point, lift the reservoir cap up so that the seal is broken and the cap is loose. Now remove the screws, while keeping the cap from falling. Fill the reservoir, replace the cap, and snug (but do not overtighten) the securing screws.

ALWAYS use DOT 4 brake fluid!

If the engine dies when the clutch is released, this may be the kickstand safety switch (see ELECTRICAL).


DRIVE TRAIN:
The drive train is a standard manual transmission, with power from the transmission delivered through a drive shaft to the Final Drive. The U-joint is at the output shaft of the transmission, protected by a conical, constant-volume rubber boot. U-joints were uprated with stronger construction, and newer U-joints will fit on the earlier bikes (requiring a newer-type boot).

Lubrication of the splines in the drive train MUST be done with a high-molybdenum paste (NOT grease). The magic number is 60% molybdenum -- anything below that is not suitable. Loctite 51048 is a popular spline lubricant.



ELECTRICAL:
The GL1500 uses a 12-volt YTX24HL battery, which feeds through fuses and relays under the seat and a LOT of wiring. Remember that, even though it's smaller than a car, the loads on the electrical system are pretty much the same -- light bulbs, gauge innards, etc are automotive types -- so the wiring will be the same gauge as found in your four-wheeler. The alternator is a small Japanese car type.

You will need a Volt-Ohm Meter (VOM) for checking voltage, wire continuity, etc, but this can be a cheap Harbor Freight type.

There's a lot of discussion in the Forums about electrical issues, so I won't go too deep into it here. The most important thing to know is that if you see any fault, start by checking switches, fuses and ground connections, in that order.

One common failure is for the engine to die when the clutch is released. The kickstand safety switch and its connections are down where water, oil, road crud, etc can cause problems. Work the switch a few times by raising and lowering the kickstand, and this may solve the problem.

In fact, the switches are exposed to a hostile environment not found in the family grocery-getter, so are more likely to become contaminated with dirt or water, affecting operation and performance. If you have anything that doesn't seem to be working, work the related switch a few times and see if that helps.



ELECTRONICS:
The full-dress factory electronics package for the Goldwing includes an AM/FM Stereo/tape player, with integral intercom and CB radio which works for both riders. This whole package was custom-built specifically for the Goldwing.

There is no provision for adding auxiliary inputs, leading to some how-to files showing how to modify the radio. It is also possible to put a Bluetooth adapter inline between the radio antenna and radio.

A number of owners have adapted other electronics as replacements for the factory radio. Hunt around in the Forum for information.



FORK BRACES:
For some reason, Honda designers failed to put a solid brace across the top of the lower forks/fender of the heaviest motorcycle they ever put on the road. The stamped sheet metal support for the front fender is generally considered about as useful as an afterburner on a turtle. A solid brace makes a significant increase in stability and safety. These are simple to install, but READ DIRECTIONS FIRST to avoid the time-wasting mistake of dropping and having to refit the fender support.

The two most common braces are:
Blackwing (available on eBay or direct)
Superbrace (www.superbrace.com)

Either is worth putting on. The Blackwing seems to have better reviews.



JIS SCREWS: See TOOLS


LUBRICATION:
Drive train splines need molybdenum-rich paste (minimum 60%) -- NOT grease -- such as Loctite 51048.

OIL MUST MEET JASO MA SPECIFICATION. Your Goldwing has a "wet" clutch, meaning that it is bathed in oil, which is shared with the engine. Modern car oils have FRICTION MODIFIERS which will make the clutch slip or even lose material. There are special motorcycle oils, or you can use Diesel oils such as SOME Rotella or SOME Delo grades. CHECK THE BOTTLE or check their websites. Just remember the phrase "No M A, No WAY!" when shopping for oil . . .but also remember that the JASO certification process costs money, and some companies don't want to spend the money to prove that their oil is good for our bikes. Thus, some oils are suitable, even without mentioning JASO on the bottle, but anything with "Efficiency" on the label probably is not.

Essentially, the closer to the dinosaur, the better the oil for the Goldwing. Synthetic oil which meets the JASO MA standard is also popular.

The quickest way to lose friends on a motorcycle website is to ask which oil to use.



OIL: See LUBRICATION



SPARE PARTS / CONSUMABLES:
If you are planning to ride out of town, riders have suggested the following spare parts:
FUSES -- at least one each of every rating used on your bike
RELAY -- to replace the one that seems to be the most fallure-prone
SPARE KEY -- hidden somewhere secure and inconvenient, I keep mine in [REDACTED]
OIL -- one quart should be sufficient
SPARK PLUG -- one should be sufficient
PAPER TOWELS



SPARK PLUGS:
NGK Standard Plug - DPR7EA-9 (Gap .035")
NGK Iridium Plug - DPR7EIX-9 (Gap .035")
Torque: 11 ft/lb (15 N-m)

12mm thread diameter



TIMING BELTS:
In case you missed it up at the top, or you didn't believe it, allow me to repeat myself:

If you have just bought a Goldwing before the 2001 model year, verify WITH DOCUMENTATION that A), the timing belts have been replaced in the last two years, or B), the belts were replaced within the last 4 years or 50,000 miles (whichever comes first) AND that it has been regularly ridden (2,000 miles or more each year) since the belts were replaced. If either of these is not true, REPLACE THE TIMING BELTS IMMEDIATELY.

"Immediately" in this case means BEFORE you start the engine. A timing belt which is about to fail may look like one which was just installed. The GL1500 has an "interference" engine, meaning that the pistons and valves take up some of the same space at different times during each engine cycle. If a belt fails, the pistons will strike the valves, turning your engine into modern art!

Honda figures the life of these belts at UP TO 100,000 miles, but that is with the bike being constantly ridden, to keep them supple. If the bike isn't regularly ridden, the belts can take a set, and fail rapidly when the bike is started. A timing belt which is about to fail may look like one which was just installed.

Replacing timing belts is a relatively simple job, which the average owner can do with common tools.

The OEM belt is the Gates T275 (21/32" x 33", 88 Teeth). These are inexpensive, and intended to be replaced in pairs.

While Honda DOES say to check timing belts at about 25,000 mile intervals, it's almost as much work to inspect as to replace them. They are cheap enough that you might as well swap them out.

While doing the timing belts, the cooling system will be drained. This is a good time to give it a full inspection and fill with new coolant.

viewtopic.php?f=14&t=9774

After removing a timing belt from service, it's a good idea to cut it, right away, to avoid accidentally remounting it.



TIRES (STANDARD):
The GL1500 tire sizes:
Front 130/70x18
Rear 160/80x16

Important values and wrench sizes when changing tires:
Front Axle Bolt 65 ft/lb (90 N-m)
Front Axle Pinch Bolts: 10mm 18 ft/lb (25 N-m)
Rotor cover bolts 8mm

Rear Axle Nut 80 ft/lb (110 N-m)
Rear Axle Pinch Bolts: 12mm, 23 ft/lbs (32 N-m)
Exhaust Joint Pipe Bolt

Balancing Beads 1 ounce per 13 pounds of total wheel weight.

Motorcycle tires have a standard lifespan of 4 - 6 years. Dunlop states that the Elite 3 tire "should be removed from service 10 years from date code and inspected annually every year after 5 years in service. Weather checking on side walls, any abnormality along tread and tread groove are things to keep any eye on. Many variables come into play when a tires age comes into consideration. Tires usually wear out before they age out." This advice will also pretty much apply to any tires on the Wing.

What is the date code, you might ask? This is a series of four digits, located at the end of the DOT code molded into the side of the tire. The digits are the number of the week (1 to 52) and last two digits of the year that the tire was made, are are often in a "cartouche," an oval shape made by a metal plate that is inserted in the tire mold for just that one week, then never used again.

When shopping for tires, remember that the GL1500 curb weight is over 800 pounds, and get tires with a weight rating sufficient to carry the motorcycle, rider, passenger, tools, luggage and a big sack lunch.

There is NO EASY WAY to change the rear tire on a GL1500. There are ways which are not as difficult as others.

Trailer hitch/receiver frames generally block removing the rear axle and prevent rolling the tire out the back. For this reason, it may be advisable to only install hitch/receiver when planning to tow.

The recommended techique for getting access to the rear wheel, brake, and final drive is to simply remove the saddleboxes, as per Da Book.

There is a NON-RECOMMENDED technique for hinging up the rear storage as a single unit, rather than taking off the saddleboxes. While they can be hinged up by a single person, hinging them back into place is a TWO-PERSON procedure. Even with a helper, it is LIKELY to cause damage to the plastic grommet tabs.

Repair of broken grommet tabs and other parts of the Tupperware will require ABS cement or the use of ABS welding (heat or chemical). Other types of glue may work temporarily, but will eventually fail.



TIRES (DARKSIDE):
"Darkside" means using a car tire on a motorcycle, generally but not exclusively on the rear. There are reasons to consider this, and reasons not to do it. Plenty of discussion on the subject all over the Internet and in the Forum, make up your own mind.

The equavlent tire size for the GL1500 rear is 175/75-16.

However, this is an oddball size, and availability varies, so different sizes are also popular. For the GL1500, Darkside tires which have been recommended by various adherents include:
Achilles Multivan 195/65/16
General Tire Altimax 195-55-16
Goodyear Assurance 175 60R16



TOOLS:
The most important tool that you probably don't have is a JIS screwdriver. There are no Phillips screws on a GL1500, if you look closly you will be able to see the difference between JIS and Philips screws and drivers.

The Philips configuration is specifically designed to limit applied torque by allowing the driver to cam out of the screw. This means that the Phillips driver will damage the JIS screws you want to work with.

The Goldwing is a Metric bike. A good set of metric wrenches and sockets will be necessary. Extra 10mm sockets are a good investment.

You will also want a Volt-Ohm Meter (VOM) for working on electrical systems. It is not necessary to spend a lot of money on one, and there are compact units for carrying in a saddlebox.

The factory tool kit was in a custom plastic box, which was held in the left saddlebox with a rubber strap.



TUPPERWARE:
The "hard candy shell" of the GL1500 is not only for beauty, it improves the riding esxperience, but ducting cooling air used to keep the engine happy, guiding that air away from the riders on a hot day, and holding the vents that direct warmth on a cold day.

The plastic shell is made of Acrylonitrile Butadiene Styrene (better known as ABS), which transitions from solid to liquid at 221 degrees Fahrenheit. It has the beneficial characteristic of re-solidifying without significant degradation, and there are several excellent plastic-weld products which work with it.

Repair of broken grommet tabs and other parts of the Tupperware will require ABS cement or the use of ABS welding (heat or chemical). Other types of glue may work temporarily, but will eventually fail.

Most of the Tupperware on the Goldwing is too thin to use for mounting anything that is heavy, will vibrate or flex. It's best to find metal underneath for any such accessories.

Riders have reported losing the side covers on the road. Ways to prevent this are to keep the passenger footpads folded up when not in use, and many riders advise gluing a leash on the inside of the cover, which is attached to the Wing, so that if the cover does come off, it doesn't end up in a galaxy far, far away.



WINDSHIELD:
The GL1500 windshield is a single-sheet-molded polycarbonate, which is semi-adjustable for height and which features a vent near the bottom.

Easily replaceable, there are a number of aftermarket options available, providing different height, angle, vent, and even color.

Being polycarbonate, care should be taken to avoid scratches. When possible, use low-pressure water to remove dust before wiping the surface. Use a non-abrasive cleaner or polish, and some riders like to put a furniture polish on after it is fully dry.

Height adjustment is made through the use of slots in the mounting system. These should occasionally be cleaned and lubricated with a light grease.


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