The GL engines (1000 - 1200) use "gear belts" to allow power from the engine crankshaft to turn the two cam
shafts, one in each side of the engine. Gear belts, unlike the familiar "V-belt" and "flat belt," have teeth which make
the belt act like a combination flat belt and gear. The belt teeth cause the cams to be "synchronous" with the
engine crankshaft so the cams stay in time with the crank.
If the cams are out of time from the crankshaft, the valves in the cylinder head will hit the piston and cause severe
engine damage. This ocurrs when the cam pulley is off time by 3 teeth or more in a certain direction. Thus, a broken
cam belt that costs $10.00 U.S. can cause hundreds of dollars of damage or even destroy an engine. This makes a
case for proper maintenence and installation of cam belts.
Gates Corporation, a manufacturer and
distributor of high quality Timing Belts. These Gates belts are often used as replacements on GL1100 / 1200s and
are availiable at most Auto Parts stores and at any industrial belt supply house.
Timing belts are not as simple as "go throw a set on." This invites disaster. Neither are they simple to handle
or install. Some basic information will help you install your own or at least help identify a belt in need of
replacement.
The questions about belts are lumped in three general categories:
1.) When to change belts
2.) How to change belts
1.) "When?"
As before, IMMEDIATELY if it is unknown when the last change was done. A broken belt at highway speeds can
destroy an entire engine and at worst, COST YOUR LIFE in an accident when the engine locks up and rear tire skids.
DANGER -- NEVER TOUCH A RUNNING GEARBELT,
THEY CAN CATCH A FINGER AND DRAG IT INTO THE PULLEY.
NEVER PUT YOUR FACE NEAR A RUNNING GEAR BELT, NOR IN A
POSITION THAT PLACES YOUR FACE IN LINE WITH A RUNNING BELT.
BELTS CAN COME OFF WITH GREAT FORCE AND HURT YOU.
Belts must be changed as follows:
a.) if they are more than six (6) years old (based on storage life). Storing a Gear Belt at 100*F
reduces its storage life in half (3 years instead of 6).
b.) if any surface of the belt is cracked
c.) if any cords in the belt are sticking out
d.) if they are noisy
e.) if engine speed exceeds 6,000 RPM (based on speed limits for the belt, I have routinely exceeded
that speed but dont recommend it. Ive done lots of stupid things on a Goldwing I wont even begin
to tell you about.
f.) more frequently if the cycle is overheated or stored / operated in very hot or cold weather
g.) if anything falls in the belt teeth while running.
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a.) NEVER drop, twist, stretch, bend backwards, pry on a Gear Belt. Do it once, throw it away.
b.) Avoid storing Gear Belts exposed to sunlight, in wet locations, over 85*F, in airflow from
a heater, near electrical transformers or motors that generate ozone, near solvents or chemicals.
c.) NEVER bend a Gear Belt backwards (with teeth out).
d.) NEVER bend a Gear Belt to a diameter smaller than the smallest pulley (engine crankshaft pulley).
e.) NEVER use a Gear Belt that was hung on a nail or other support that places the belt weight
on a smaller diameter than the smallest pulley. This can break a cord in the belt. If the belt hange
long enough on a nail or other small diameter object, it will form to that small diameter and be
stressed when put on the engine.
f.) NEVER buy a belt that has been repackaged, they must be stored in their original box, and not bent
to a smaller diameter than the small pulley (crankshaft pulley) while stored in the box.
2) for installation---
a.) NEVER, EVER, for ANY REASON pry a gearbelt onto a pulley. Not even a little! It could cost you an engine.
b.) NEVER turn a pulley to put tension on a belt. Belts are to be installed with no pulley tension.
c.) NEVER turn the engine by the cam pulley. This places all the engine torque on one cam belt.
d.) Pulleys must be clean. Rubber build up on pulleys can damage gear belts. Clean them with a cloth moistened
in carburetor cleaner. Avoid spraying carb cleaner on pulleys. Allow the pulleys to completely dry before
installing the belt or the belt could be damaged by the solvent.
e.) It is CRITICAL to be sure the cam pulleys (large pulleys) are "in time" with the crankshaft or valve damage
will occur. This is not easy as when the engine is set to TDC, the right cam will jump out of alignment when
its belt is removed, and you may not notice its happened.
f.) Ensure the belt is installed on-center both pulleys, with no belt hanging over any pulley edge.
g.) Proper installation tension is CRITICAL and difficult to set. The Factory tensioning idler system is well
designed, but there is no gurantee the tension springs, which are now about 20 years old, have the proper
tension. The spring may or may not be the proper tension, I have not verified it. Proper belt tension must
be calculated.
The belt tension required by Gates is within 0.1 pounds of force on the belt at a certain location
for a certain "belt deflection." IT IS NOT ENOUGH TO JUST PUSH THE BELT A CERTAIN DISTANCE
TO ESTABLISH TENSION, IT MUST DEFLECT A DISTANCE WITH A CALIBRATED FORCE.
DO NOT CHECK TENSION ON A GEAR BELT AS YOU WOULD A V-BELT (by "pinching" it between
two adjacent points) THIS WILL RUIN THE BELT.
f.) Once installed, I always turn the engine over by hand several revolutions then recheck alignment to
gurantee the belts have not "jumped time." Then I crank the engine over without spark plugs installed
recheck them, then run the engine a few minutes and recheck both timing and tension.
Now the detailed procedure :----
Parts and supplies:
2 timing belts (available at Napa Auto Parts) # Gates: T275 NAPA: 250275 Should be about $27 each
2 tensioners, if needed. (honda only) available thru some of the honda parts folks online. About $70 each.
4 Quarts Honda non-silicate antifreeze (I don't substitute) Around $5 per quart.
6 NGK original spark plugs from the Honda Dealer (I don't substitute except for Iridium type).
You might also need:
Silicon Adhesive to stick the rubber cover gasket back on.
Silicone lubricant.
Anti-seize compound (Any auto parts store)
A small dry paintbrush to clean the dust like stuff out of the timing housing.
A black permanent marker to mark the cams BEFORE you take off the old belts.
A bucket to catch the antifreeze when drain at the water pump.
Rags
Tools:
Motorcycle Lift ($60 at Harbor Freight)
Tie down Straps ($12 Harbor Freight)
3/8 Torque Wrench ($20 Harbor Freight)
3/8 socket wrench
3/8 3" extension
4mm, 7mm, 8mm, 10mm, 12mm, 14mm, 17mm sockets, Spark Plug socket
Wouldn't hurt to have those sizes in open end and box wrenches either.
6" #2 Phillips Screwdriver
Stubby #2 Phillips Screwdriver
3/8" blade screwdriver
Awl
I also like to have handy a mirror and long flexshaft magnetic pickup tool.
Disassembly:
You must remove the lower fairings to gain access to the belt areas.
First, remove the battery NEGATIVE terminal connections. (I also do the POSITIVE side) Under the right side panel. 
Be sure to take steps to insulate the leads from the battery.
Remove the right and left engine covers. They are held with one post and rubber grommet. So
they just pop loose as you lift them away at the rear portion, then slide the whole panel up and out.
Here is the left side of the bike with the engine cover off.
Pull off the spark plug wires inline with the plugs. Make absolutely sure the sockets are clean.
Using the Honda toolkit sparkplug wrench and a 17mm deepwell to remove the sparkplugs.
Lay them aside if you will be reusing them. Decide if you want a spare to carry even if you plan to
replace them. Do not replace them yet. Leave the holes open. You will need them to breathe later
when you rotate the engine by hand without the resistance of compression.
Stuff clean shop rags in the spark plug holes to keep debris out of the engine cylinders.
Many of the next steps must be performed to make room to allow the timing belt covers to come out.
That ribbed bulge looking hose between the frame and the radiator hose is the heater hose.
You will be pulling that out from between the frame and the engine at the bottom after you unplug it.
Note: Some gurus I know prefer to leave this hose plugged in and just pull some slack up from the
bottom enough to allow the timing belt cover to be removed. Either way, it's your call.
Unplug the heater hose under the bike frame from the exhaust manifold header. It just pulls off
by pulling it toward the front wheel. It's a little tight because you are compressing the hose and
the bend is fairly close by. But it will just unplug before you run out of room.
Here it is off with the manifold connection just behind it. Slide it up through the frame to get it to
hang free. You can move the radiator hose to help make room to get it out. It needs to go back in
the same place so take note of it.
This is a crappy picture but you can see the small black wire going down the center of the picture
and behind the frame. If this were a little bit longer, you could leave it on, but alas, it isn't.
Under the bottom frame that wire attaches to the oil sensor mounting screw under the rubber boot
shown here. Take your tougher fingernails and force the large part of the bottom of the rubber boot
to the left toward the wire. It's tough but it will come off. It's not glued or anyting. Once you get the
boot back enough to expose the wire terminal, unscrew the phillips/hex head wire terminal screw.
With the terminal removed, slide the wire and boot up above the lower frame and let it hang in front
of the frame and timing cover.
Before you do the next section, be aware that I have heard that you don't need to drain the coolant
and remove the radiator hoses in front of the timing belt cover to get them off. That would save
some time, hassle and several steps. However the radiator hoses would still be in your working area
and if it were time to change the coolant anyway I wouldn't think anyting about the extra steps.
Also note that when I was doing mine the first time, I found it difficult to remove the covers with the
hoses in place. Since then, when I go back into that area I just do the coolant drain anyway.
Again, your call. Nice to know anyway. Assuming you want to proceed with the coolant drain
approach...
Now we need to drain the radiators because the radiator hoses are in the way (of course). To
remove the radiator hoses you will need to drain the radiators. To allow air flow from the top inside
the radiators, you need to remove the radiator cap. It is located under the right cover in the steering
area. To remove that cover, start at the forward end and pull the assembly back to release a slide-in
tab. Then work your way down the side, pulling the second tab out by pulling toward the center console.
After that, move the handlebars all the way to the left so that the lower panel section is available.
Finish the side tabs and finally pull the inner wall toward the outside of the bike to release the last tab.
Slide the cover out.
Here it is removed. You can see the tabs.
Finally, the radiator cap. Remove it by turning it counter clockwise hard and lifting it straight up.
This is a good time to service the radiator or change the antifreeze if you need to.
Look inside the radiator to make sure there is not a problem like cottage cheese or worse.
Leave the hole open for now.
Set up some buckets for a gallon of antifreeze and remove the coolant drain bolt under the water
pump with a 10mm box wrench.
Let it drain good. You can re-use the coolant if it is in good shape and if you keep it clean. Honda
coolant is very dark green and looks dirty except when you can see through it. If this is a new bike
to you, or the coolant is over a year old, I would change it (like all unknown fluids). You can get 4
quarts of Honda premixed coolant for less than $20 at the dealer. Others may use other things, but
this is one of the things I stick to Honda on. Either way it must be silicate free for aluminum engines.
Once the coolant is drained and set aside, you can remove both radiator hose clamps and hoses with
a 3/8 inch blade screwdriver or a hex nut driver, I don't know which size (sorry). I like the screwdriver
because I constantly over-torque and break the bands when I tighten them with a hex nut driver.
Let the loosend clamp bands slide down the hoses and sit there.
Removing the hoses is just pulling on them downward while rocking them side to side. Don't bust
a knuckle when they finally come off.
You are finally ready to start removing the 3 center timing cover bolts and the 11 (each) 10mm
bolts from the main covers. I like to use a 1/4 inch drive socket for this. I like to feel smaller
bolts with smaller tools. These bolts are staggered top and bottom all the way across the two peices.
Remove them all and the center cover. The belt cover will not slide out with the timing cover still on.
There will be 3 very short bolts (center cover) plus 8 medium and 3 long bolts (timing belt covers).
Here are where the three long bolts go back in. On the main cover only... 1. bottom left, 2. bottom
center just left of the timing cover, 3. Top just right of the timing cover. All the rest are mediums.
There are the 11 timing cover bolts not counting the three shorter timing cover bolts.
Note the anti-sieze compound on the threads. Honda calls for a locking compound. I don't, but
you might want to consider it since it's ' Honda official'.
Once you slide both cover halves out each side, you will be rewarded with the mother lode.
Note: The rubber grommet material lining the covers may come loose. It is reusable unless damaged.
Just clean it up with soap and water and let dry, then glue it into it's channel with a light bead of
silicone seal adhesive and press the grommet into the channel trying to make sure it is flat and the
same height everywhere. Just before putting the cover back on, I like to put a film of silicone
lubricant on the mating edge with my finger. The covers slide in easier, seal better and may come off
easier next time.
You may notice some redish dust near the tensioners. This is a sign to me that the tensioner bearing
seals if not the bearings themselves are getting in a worrysome state. I would change them with the
belts despite the noticable extra costs because belt loss will cause engine damage and tensioner failure
can cause belt loss, and this much work is not practical on the road in the middle of nowhere, if you have
an engine worth repairing in the field, left at all.
Before removing ANYTHING, set the existing timing points and mark them with a felt pen so you
won't get things out of alignment later. You must realize that the center crank gear turns twice for
each single rotation of the outer cam gears. So it's REALLY easy to screw yourself 180 degrees off.
ALIGN AND FELT PEN
ALIGN AND FELT PEN!
Set the crank gear with your 17mm ratchet first to the alignment mark by turning the ratchet
counter clockwise. The timing mark is at 3 oclock, embossed in the aluminum chassis and the
marker you want to align it with is stamped 1.2 F-T The line between the F and the T is the alignment
mark. It's hard to get your head in there with the wheel on so use a straight edge to get it right.
Now check the cam marks. All cam face plates should read "UP" at 9 oclock and 3 oclock.
The chassis alignment marks are shown in the Honda manual as being on the inside of the cams.
I prefer to align on the marks on the outsides of the housings, since alignment is alignment.
Remember all cam pulleys MUST show the words "TOP" right-side-up or your crank pulley needs
another 360 degree rotation because you are 180 degrees off of alignment.
Once you know what that all looks like, you can begin to remove the tensioners. If you ONLY intend
to change the tensioners, you can use my little trick. Verify the alignment as we have just done and then
tie a velcro strap around the belts on each side so the alignment can't change while the tensioners
are off. Tensioners come out and back in...no problem. If you are changing the belts too you can skip
the trick because the belts have to come off anyway.
Notice that the tensioners have a washer on the side that slides and not on the side that pivots.
Also note that when tightening the tensioners, you will put in both bolts just less than tight so the tensioner
can slide with little freeplay and when you finally torque the bolts down, the washer bolt goes first.
The spring hooks from the back to the front in the hole in the tensioner bracket. The other end of
the spring hooks onto a brass pin behind the belt path.
Tensioner and spring removed. Now remove the two black pickup sensors that bolt near the center
crank pulley. They are mounted with two bolts. You can see one of them in the top left of the next picture.
These don't adjust, when you put them back just bolt em in. They have to be off to get the belts off and on.
Just let the sensors hang by their wires for now. Also remove any rust and debris from the sensor faces.
Note: Be sure to keep track of which sensor is which and how each faces the timing disk.
Several people have reported a problem with starting or running incorrectly after belt changes.
They found they had either swapped the sensors or put at least one of them back in facing away from the disk.
Also make sure you note how the wire holder went on so you can get that back right again. Two have reported
pinched or crushed wires and one had the belt wear through a wire that had not been secured properly.
None of this caused any engine damage but they had to tear down to go back in to find it and fix it.
Go ahead and change the belts now. Be careful to keep the new belts clean and oil free.
Wash your hands first. Remember which belt came off first so you can put it back on last.
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If you need to know how to replace alternator on GL1200:-------
Start by removing both fairing lowers, left horn, radiator, fan assembly & air duct on left side.
You will have to cut the brace out that the horn bracket is welded to. Grind the upper end flush with the flat part of the bracket, as there is a reinforcement plate to go there ( pic 027). I used a piece of ¼ X 1 ¼ flat stock to make the reinforcement plate. It has to be tapered to fit. Drill 2 holes to match up with the bolts that hold the fairing to the bracket. Install plate and just snug bolts, as you will be taking it back off shortly.
Remove the left engine to frame bolt that is just above the timing belt cover, inboard of the intake manifold. This is where the lower alternator bracket will fasten. I used a piece of 1/8 X 1X1 angle iron for this. It will be about 3 ¼ inches long. Drill a 13/32 hole 7/16 from one end & 5/8 from the bottom then drill a 3/8 hole 2 5/8 from that one, in same side. Install the bracket using the engine to frame bolt. Trial fit the alternator (you will have to trim the alt. some) using a 3/8 X 3 bolt using flat washers to space it out to just clears the intake & so the belt will clear the timing belt cover. You will have to put the left cover back on for this.
With the alternator roughly in place it is time to install the crank pulley. Take the left cover back off and remove the crank bolt. You will need a longer bolt (about 1 inch longer). Put the crank pulley on using the longer bolt and flat washers as spacers, add or subtract washers so the belt is in line with the alternator and clearing the timing cover. You may have to move the alternator in or out a little. When you have the two lined up measure the thickness of the washers and make a spacer to replace them. The hole in the crank pulley I used was too big so I made a bushing and spacer together. Install the crank bolt with Locktight.
Next you will cut the timing covers to fit around the new crank pulley. Just cut it enough to fit around the pulley (go slow, might as well polish them at this time). Put covers back on.
Put the belt on and pull it tight. Pull the alternator up against the reinforcement plate you made earlier. Make the adjustment bracket and tack in place (pic 23), remove and finish weld (pic 032). Paint & reinstall. You will have to trim the front screw bracket that holds the fairing lower.
The bottom of the radiator needs to be moved forward about 5/8 of an inch. I made 2 spacers that screwed onto the original mounting studs (pics 36& 39). The mounting bracket for the fairing lowers now go behind the radiator. The bottom hose will reach the engine, just loosen both clamps and wiggle it around a bit. The fan mount will have to be altered some. You will have to remove the left lower leg from the fan mount(pic1). Bend both lower leg mounts toward the radiator core( pic3). I ground a little off of the lower fan shroud to get the fan blade as close the radiator core as possible. This is done to lessen the amount the radiator will have to be moved forward. Both fairing lowers will have to be trimmed some around the lower part of the radiator. The left lower will have to be fitted around the alternator. I used a torch to heat the backside and while still hot put it in place and mold it around the alternator ( pic 17 ). Be careful while heating as not to get it too hot and bubble the paint or melt the plastic. A heat gun would be better. There is a heat shield that will have to be trimmed to clear the alternator also.
See images below for more detailed help:---
