Most of us who have played or own a Jagmaster agree that the stock pickups are not great. However, since Fender deliberately retrofitted the guitar with humbuckers as one of its main selling points, I think it is helpful
to know how to get the most out of the stock units.
To get a balanced tone out of the units I found it helpful to carefully set their distance from the underside of the strings. I set the bridge unit between 2 and 2.5 mm from the top of the poles to the underside of the strings, and adjusted the neck unit until its output was balanced, making sure it was about the same distance from the strings on both sides.
Adjusting the Pole-Pieces-
If you find that the tone is still too bright, it may be time to utilise the adjustable polepieces (the ones with the screwdriver slots) , using them as a crude kind of tone control. If the pickup is too bright, lower the polepieces underneath the treble strings, maybe a half or full turn of the pole, and raise those underneath the bass strings, about the same amount. You have to judge what is correct for yourself, but I set it so that the polepices gradually get higher as you move from the high E to the low E string. These techniques are one way to get a more balanced tone out of the stock pickups.
Click here to see a cool page detailing a Jagmaster player's own personal modifications