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Another disregarded item on your bike, is the drive belt. Occasionally, it's tension needs to be checked, and as well, needs to be adjusted. To do this properly, you'll need an inexpensive tool from HD, pt# 40006-85. I don't recall what the cost was, but it was less than $20 if my memory serves me.
The reason for proper belt tension, is for the longevity of the belt, proper tension of the belt in relationship to the wearing of the pulleys, and to prevent the belt from slipping and tearing teeth, costing you a decent penny to get it replaced. The predetermined adjustment is to be done when the bike is COLD, as the pulleys get warm and expand after being run, and can make the belt tighter. Too tight of a belt can prematurely wear the pulleys, the belt and puts excess strain in the inner primary support bearing, and can cause it to fail.
Most bikes have a black plastic dibris deflector over the belt. That deflector has a small window in it, below the lower belt line, with "lines" on it. These lines are fraction (inch) measuring marks, to let you know how much deflection the belt's showing.
Here's a pic of the tool and deflector, showing the tool in use: (From the HD instructions)
The tool has a preset spring inside, and an adjustable O-ring that is moved to the number of pounds (lbs) you need to apply, to find the belt's deflection.
First, you need to read your manual, and see what your bike/year/make calls for, and you also need to know if it calls for the bike resting on the jiffy stand, or with a rider's weight on the bike. Mine (1995 Dyna) calls for 10 lbs pressure, with a rider on the bike, showing 5/16" - 3/8" of deflection.
Set your O-ring to 10 lbs and place it in the middle of the belt span, between the rear sprocket and the rear tire. The tool needs to be perpendicular to the belt, and not on an angle. (90*)
(From the HD instructions)
Being used, in place (note O-ring at the 10lbs mark) :
Not compressed:
Compressed:
Note belt deflection: (upward)
On my bike, with a ruler with preset markings, you can see the deflection and the given, premarked settings allowed, of 5/16"-3/8" allowable deflection, COLD, at 10 lbs of pressure.
If you have too much, or not enough deflection, remove the rear cotter pin from the axel nut and loosen the nut, in turn, loosening the rear wheel.
Using the axel adjusters, turning them in INCREASES belt tension, reducing deflection, OR turning them out, REDUCES belt tension, increasing deflection... If you need to turn them out, you'll also need to push the tire/wheel in, to seat the adjusters. :
Make sure you keep your rear wheel straight, and using the factory marks on the swingarm, (holes) you can use a piece of bent wire with a 90* bend, inserting the wire into the holes, and measuring the distance from the measuring hole, to the center of the rear axel. There's another special too for that, but a piece of bent coat hanger with a piece of tape on it, and a magic marker will perform the same function, just fine.
Afterwards, retorque your rear wheel to the proper spec, check your belt deflection again, and remember to replace the cotter pin in the castle nut, on the rear axel. I never reuse cotter pins, and have a reusable clip that's retained with safety wire. Your results may vary.
The reason for proper belt tension, is for the longevity of the belt, proper tension of the belt in relationship to the wearing of the pulleys, and to prevent the belt from slipping and tearing teeth, costing you a decent penny to get it replaced. The predetermined adjustment is to be done when the bike is COLD, as the pulleys get warm and expand after being run, and can make the belt tighter. Too tight of a belt can prematurely wear the pulleys, the belt and puts excess strain in the inner primary support bearing, and can cause it to fail.
Most bikes have a black plastic dibris deflector over the belt. That deflector has a small window in it, below the lower belt line, with "lines" on it. These lines are fraction (inch) measuring marks, to let you know how much deflection the belt's showing.
Here's a pic of the tool and deflector, showing the tool in use: (From the HD instructions)

The tool has a preset spring inside, and an adjustable O-ring that is moved to the number of pounds (lbs) you need to apply, to find the belt's deflection.
First, you need to read your manual, and see what your bike/year/make calls for, and you also need to know if it calls for the bike resting on the jiffy stand, or with a rider's weight on the bike. Mine (1995 Dyna) calls for 10 lbs pressure, with a rider on the bike, showing 5/16" - 3/8" of deflection.
Set your O-ring to 10 lbs and place it in the middle of the belt span, between the rear sprocket and the rear tire. The tool needs to be perpendicular to the belt, and not on an angle. (90*)
(From the HD instructions)

Being used, in place (note O-ring at the 10lbs mark) :

Not compressed:

Compressed:

Note belt deflection: (upward)

On my bike, with a ruler with preset markings, you can see the deflection and the given, premarked settings allowed, of 5/16"-3/8" allowable deflection, COLD, at 10 lbs of pressure.

If you have too much, or not enough deflection, remove the rear cotter pin from the axel nut and loosen the nut, in turn, loosening the rear wheel.

Using the axel adjusters, turning them in INCREASES belt tension, reducing deflection, OR turning them out, REDUCES belt tension, increasing deflection... If you need to turn them out, you'll also need to push the tire/wheel in, to seat the adjusters. :

Make sure you keep your rear wheel straight, and using the factory marks on the swingarm, (holes) you can use a piece of bent wire with a 90* bend, inserting the wire into the holes, and measuring the distance from the measuring hole, to the center of the rear axel. There's another special too for that, but a piece of bent coat hanger with a piece of tape on it, and a magic marker will perform the same function, just fine.
Afterwards, retorque your rear wheel to the proper spec, check your belt deflection again, and remember to replace the cotter pin in the castle nut, on the rear axel. I never reuse cotter pins, and have a reusable clip that's retained with safety wire. Your results may vary.