How to stiffen the steering post. (Requires a die grinder and a welder.)
Polaris in their wisdom realized steering posts needed to be reinforced, so what they did was slide a short section of pipe inside the steering post pipe, and weld it in at the top, which also added some weld to the top of the plate. What Polaris DID NOT take into consideration was the length of that inner reinforcing pipe, at least not on my sled, as the inner pipe only went as far as the hoop / upper steering support. And of course where it bends is right below that…
Here is the fix that I came up with to stiffen the steering post on mid to late 80’s Polaris. Whether it will work on newer models I don’t know, as I don’t have a new sled.
The steering post on my 98 XC600 was tweaked when I got the sled, so I muscled it back into place. And my daughter and I both dumped the sled once and tweaked it again, and every time I muscled back into place you could feel it getting weaker.
Here is what I did to fix it. First, square up your bars so they are sitting straight, you can even go as far as grabbing a tape measure and triangulating a measurement to make sure they are perfect. Next ,unbolt the handlebars and carefully lay the whole works with wires and cables still attached as far forward as you can. On my sled there is a square or rectangular steel plate welded to the top of the post, you will see a bead of weld on the underside of the plate as well as on the top where it is welded to the pipe. With a die grinder and a high speed burr, carefully grind out the weld on the top being careful not to grind through the plate, as metal is removed you will see a parting line begin to show for the inner pipe. Once you can see the parting line all the way around, take a wire coat hanger and straighten it out, and put a V on one end that is narrow enough to slip inside the inner pipe, snag it, and pull it out. (on my sled it slid right out with ease)
On my sled the steering post goes down past the hoop and inch or two, then has a dog leg in it to clear the air box and oil tank, so I took a measurement from the top of the pipe to that first bend, I thnk it was around 10 inches. And I also measured the inside diameter of the steering post pipe, I think it was 3/4 inch. I then made a trip to my local Fleet farm and bought the longest 3/4 inch bolt I could get my hands on, I think it was 12 inches long.
Now, from under the hood on the Right side, find a spot where you can easily get to the steering post to drill a hole without taking half the sled apart, I was able to find a spot about an inch below the hoop, and I drilled a 3/8 hole in the side of the steering post.
Then I slide that long a## bolt down the steering post until it stopped, and marked a spot on top with a sharpie about 1/4 to 5/16 of an inch above where I cut out the previous weld, removed the bolt and cut it off at the sharpie mark. I slide the bolt back down the steering post and gave it a couple firm smacks with a hammer until it was lined up nicely with the cut out weld area. Now weld a bead around the top where it was previously welded, and also plug weld the bolt to that 3/8 hole drilled into the side of the steering post just below the hoop. Let it cool off, touch up the paint and put it back together !!