Hi Gary
I also have a 125 with a QA42 and I love it. Below is a picture of a spacer I made to get enough "down" to get my QA42 to touch my driveway.
The red arrow is the adjustment flat bar that controls how far it goes down. The yellow arrow shows where the bolt to adjust the plate is located. It's a 3/4" nut ( 19mm will work too ) and just slide it towards the front wheels to make the thrower go lower.
The QA42 works best at WOT ( wide open throttle ) and keeping the thrower loaded with snow. Adjust forward speed to get best throwing distance.
https://www.youtube.com/watch?v=tfWy8jbj_GY&t=2s