I just bought a 1990 250 Trail Boss 4x4. It needs a few repairs and I was wondering where to get a good repair & maintainance book? Also is the 4x4 only supposed to work in low range, or is something not working right.

Thanks for any info.

 

Check around the web for Clymer repair manuals. They seen to be one of the best for ATV repairs. Palces such as www.amazon.com or www.barnsandnoble.com should have them.

Your 4x4 system should work in high or low range. Whenever the switch is in 4x4, the front wheels should get power anytime the rear wheels slip at all.

 

Lurch is right on the AWD, it is supposed to work in both high and low range.

When AWD is selected the fronts will not engage unless the back wheels slip. When the back wheels slip the front hubs engage and remain engaged until torque is removed from the front wheels. Is it possible it is working on your machine? I say this because the front engagement is not as obvious when you are in high range as it is when you are in low range, it happens mostly without you knowing.

I am referencing my '98 Sportsman knowledge here but I assume it is the same for yours. There is a micro switch at the shifter that engages any time the shifter is in forward, high or low. It is possible that the switch is not getting engaged when the shifter is in high. I have no knowledge of how to adjust things if this is the case. Look it over.

The wiring from the switch should have R/W, Pur, and G/W wires coming from it. The way to test my theory is this. Locate the grey and grey/white wires coming from the AWD switch (not the shifter microswitch). The microswitch on the shifter feeds power to the grey/white wire at the AWD switch when the shifter is in LOW or HIGH. Look for power on the Grey/white wire with the shifter in neutral - it should NOT be there. Next look for power there when the shifter is in LOW - it SHOULD be there. Next look for power there when the shifter is in HIGH - it SHOULD also be there. If it is not there in HIGH, then the microswitch engagement needs adjustment (somehow). This will at least identify (or rule out) a problem with the microswitch.

As for the service manual, Polaris now prints model specific service manuals that are quite good. Unfortunately they may not have one for your model (being older), but it is worth a try. My Sportsman manual covers the Sportsman 500 from '96 to '00.

Hope this helps,

DJ