My way to mount scratchers on a 129

The first thing I did was mount the spring scratcher with the hardware that it came with. Notice the existing holes that I used right next to the idler block.

Next I had to modify the idler block to clear the spring that is now laying flat against the rail. This was easily accomplished with a 3/16” round file. The block already has a recess molded in to lay flat against the rib on the rail. I just gave it a second recess

The next step was to remove some material on the side of the idler block so that it can be mounted next to spring coil. It’s a snug fit, and I used the wheel end of my belt sander to hog some material away to get it to fit

Here is the idler block reattached to the rail with the scratcher spring laying under it

Now we are ready to reattach the idler wheel. But first I had to sand off approximately 1/8” of the plastic hub on the back to clear the spring coil hub assembly.

As this photo shows everything clears and the idler spins freely.

Here’s the finished product. The spring coil tucks in nicely behind the idler wheel. And the scratchers tips stow perfectly just in front of the bump stop on the rails. It looks like everything tucks in almost like they left the factory with them on.

I’ve got two of these 129 sleds so I decided to get a set of solid idler blocks to modify. My thinking is these should maintain their strength even though some material has been removed. I’ve taken a couple of pictures of the solid blocks to share.

These blocks need a bushing (3/8 down to 1/4) or you will have to drill the rail to use 3/8 hardware. I chose to use a bushing so that I can always remove later and return to stock.

It's been about a year since I put these scratchers on my 2 ZR 6000's with the 129 skid frames, so it's time to update. No bad news to report so far; the scratchers have worked very well. The first time I had to deploy them on hard pack my sled went from 160 degrees to 105 degrees in 1/2 mile! So far we've only had to use them briefly but they have been a lifesaver. We crossed over from St. Ignace to Mackinaw Island on the several mile long ice bridge and the temps never got above 110 degrees. The sled trail across the ice bridge had very little snow that day and these scratchers provided lots of track lube also. The sleds following me say there is a very strong shower of ice and snow chips being thrown at all speeds. I am very impressed with the performance.

These spring or wire scratchers package very well on the 129 skid. I have put over 1000 miles on the sleds since mounting and they haven't moved, shifted or lifted off the rail even once. The scratcher end stows onto the extruded lip inside the frame rail just in front of the rubber bump stop and doesn't move. And we were in some god awful moguls going into Houghton that shook our dental fillings loose, if you know what I mean. My other concern was the durability of the hollow idler block after removing some of the aluminum to allow a close fit to the spring. After over 1000 miles I am pleasantly surprised to report no failures. The solid aluminum idler blocks style also have no issues as expected since they are solid instead of hollow (see pics).

I wouldn't hesitate to install another set of these on another 129 after using these when needed this past year. I paid around $40 a year ago - I see a similar set on ebay is up to $60 now if anyone is interested in this style.

Snowmobile Ice Scratchers Polaris Skidoo Arctic Cat Yamaha Snow Scratcher | eBay