i have a 2003 330 Express and have lived with a very small sweep. If it is adjustable, I'd be excited to learn how to do it.
I got mine sorted without changing the motor and since I discected the crap out of this thing, if I have to change the motor ever in the future, I'm confident. Once you access the motor by taking that cover off from the ceiling of the cabin:
Change Sweep Angle and Parking
Should a change of wiping angle be necessary, It can be performed as follows (see illustration).
• Remove cover plate with a Philips (+) screw driver .
• Use a flat-head screw driver to remove “U” shape clip on the shaft that connects the transmission plate to the main shaft.
• Lift the transmission plate.
• Unscrew the two screws fastening the angle plate to the white cog wheel. There are two oblong holes in the cog wheel.
• If you want to change the park position, place the transmission pin in the opposite oblong hole.
• If you want to change the sweep angle, replace the angle plate, align the hole marked with the desired sweep angle with the oblong hole on cog wheel, and replace the angle plate screws.
• Replace transmission plate and “U” clip. NOTE: Additional grease may be required after changing sweep angle or park position.
Note that I posted this pic upside down because this is the orientation in which you will see it when you remove the plate.
In my case, I think someone changed the motor and didn't set it up right. I found a video the previous owner had sent me where he was running in rough water and the wiper was sweeping way more than it was when I got the boat.
When I took it apart yesterday, I found It was on 80 degree sweep, park was ok, but it would never get past mid windshield. I had to move the lever arm to 110 degrees, and also unscrew the flat plate from the plastic cog and reorientate it so park was right. I also reorientated the wiper arm itself.