I just purchased a new 2002 Sportsman 500 Ho on Oct 1, and it is awesome. It is the first Polaris I have ever owned, and I am totally pleased. But, I have a few questions. 1. can anyone explain the 4wd system to me? I know that when turned on, it doesn't engage until the rear wheels spin. I thought it was shift-on-the-fly, but I've noticed when I slide the switch to AWD, it doesn't actually "light-up" until I slow to approx. 4 mph, is this normal? 2. Do you have to back up everytime you shift out of AWD, or just when a hub locks up? My dealer told me it was like a ford w/ auto hubs, and to disengage them, I need to back-up everytime. and lastly #3. where on earth is the idle screw. It is definatley not where the manual says it is, and my almost dies when it's idling. Sorry I wrote so much, hope someone out there can help, though. Thanks !

 

Awd will engage or disengage as soon as you hit the switch. Its that simple.... No backing up or slowing down is needed!!! Idle screw IS where the manual says. Its hard to find for the first time. I believe on your bike thats its way up under neath the Carb. You can turn AWD on or off at any speeds. Just make sure your not "spinning " the back tires when turning on or off. ie. when stuck in mud and you want to turn on Awd let off the gas then hit the swicth and your all set.

Hope this helps.

1999 Sportsman 500 Warn winch and front bumper 1000miles
First Bike was a 1996 I put 2000miles on that one before I traded it for the 1999.

 

About the 4wd. You turn it on, inside each front hub is whats called a Hilliard Clutch (on the 02 700 it moved the the fromt gear case, might have moved on yours too, but it is the same idea) the clutch parts from the inside out are as follows, 1. strut tower, 2 riding on the outside of the strut tower is what the hub seal rides on and it is adjustable, 3 between the first 2 parts is the magnetic coil(looks like a thick black plastic washer(inside the coil is just wires) 4. next is the amature plate( looks like a washer with 3 prongs sticking out) this rides on the seal surface and the strut caseing 5. Hilliard clutch assem.(see note) and of course all the bearings and some washers. NOTE, the hilliard clutch, picture a nut in 1 1/2" dia. (six sides..) the "nut" sides on over the shaft, on the outside of each side on the nut is a roller, each roller fits into a cutout on the "basket"(holds in all the rollers, has 3 notches the amature plate fits into) on the outside of the basket is a spring wrapped around the assem. (hold tension on the rollers)
When you turn on the 4wd, an electrical current is sent to the coil wires, which generate a magnetic feild around them, the mag. field pulls the amature plate and hold pressure on it by creating friction between the plate and both the seal surface and some on the strut casting(confused yet??) with the 3 tabs on the amat. plate holding against the clutch basket, now pressure is held against the basket, when all the wheels turn the same speed the clutch naturally turns the same speed as the fromt tires, but when the front tires lose their speed and the clutch keeps turning, this causes the plate to hold back the bashet which in turn causes the rollers to "ride the ramp"( move to the highest point on each side of the nut) the rollers push outward against the hub itself, and turns the tire.
for all this to work right, everything must be right. The plate cant be bent(cost $5 ea.) the spring cant be streched at all(this would cause either to much or not enough pressure holding the rolloers in) and the seal surface must be adjusted right. when the assem. is apart take a perfectly flat surface, hold it across the seal surface and the strut casting, the "flat" object should be touching the seal surf. and you should have .010" clearence between the "flat" and the strut casting. Mine had .090" and the 4wd did not work.
if you want more info, just ask. Hope this didnt confuse you even more!!

 

1. Yellow did a good job explaining the mechanics of it. To oversimplify, the hub works like a ratchet when engaged. The front wheels can move faster than the axle, for tighter turning, or any other time the front wheels want to go faster than the rear. However, the front wheels can't travel any slower than the front axle (which is geared to the rear) so as soon as the rear wheels spin, the hub 'grabs' engaging the front wheels.
You can 'shift on the fly' in the sense that you can flip the switch anytime you want. It doesn't engage if you are traveling at speed, however. This is for 2 reasons. 1) if you are traveling fast, and engage the front hubs, possible handling difficulties may result and 2) if the rear wheels are spinning fast, and the front aren't, severe damage may result if the hubs are suddenly locked 'on'.


2. No, you don't have to back up. They will disengage on their own. THe only reason you would have to back up to disengage the hubs would be if they won't unhook on their own and are causing handling problems (usually tries to steer itself to one side or the other, sometimes it can pull pretty hard). Under most conditions, that isn't necessary. I could go on to say, that if they frequently require you to back up to unlock them, there may be something out of adjustment.

3. The idle SPEED screw is the screw with the big knurled **** on it. Location varies from model to model, but it is the one with the big head, that looks like it was made for turning with your fingers (usually on the side of the carb). The idle MIXTURE screw location also varies, and is much harder to describe. Best might be to go to polarisindustries.com and download the parts manual. They have exploded diagrams for everything, including the carbureter, and everything is labeled. Idle will improve as the machine breaks in. Too fast an idle can lead to it's own problems, including difficulty shifting, especially out of Low, because the clutch may grab slightly, dragging on the belt.