Worthwhile Tweaks for the Sno Pro 500

With a half-season of testing, riding and racing the Sno Pro 500, improvements have been discovered. Based on what cross-country racers have learned and changed – particularly during the I-500 – I’ve made the following tweaks to my Sno Pro 500 and can verify the improvements:

To reduce the inside-ski lift during cornering, reduce the travel of the front arm on the rear suspension. There are three holes in each of the two front limiter straps... the sled comes stock with bolts in the middle hole. Pulling up the arm to the third hole will improve cornering. I drilled a fourth hole in the straps and like this position the best. After pulling up the straps, I backed off on the front arm shock preload, to the point where the spring is just barely preloaded.

There are two mounting holes for the rear arm of the rear suspension, with the stock position in the lower hole (shown here). Moving the arm to the top hole will further improve cornering.

Arctic Cat EFI specialist Terry Anderson was a busy guy at the I-500, reflashing the ECUs on all the Sno Pro 500s. Terry reflashed my sled’s ECU, and the result is great: no more overly-rich bottom end during the initial take-off and slightly crisper mid-range. There will be a reflash for all Sno Pro 500 owners coming soon.

As a side note, the 500 EFI engine is calibrated to run on 87 octane fuel. Don’t use higher-octane fuel than 87.

It isn’t as stylie as the stock windshield, but the new tall windshield (P/N: 5639-500) is absolutely the ticket to move wind over and around the rider. It’s roughly 6.5 inches taller than the stocker. I’m an NBA-ready 5’8” tall, and the top of the tall shield doesn’t affect my view of the trail at all. Some racers cut the tall shield down a couple inches. Not me.

The front bumper only weighs a couple pounds and is an excellent piece of insurance, as racers in the I-500 proved each day.

The rear storage bag (P/N 5639-433) is fits excellent. I’ve filled my with the stock tool kit, my extra tool/parts kit, belt, siphon, beef jerky (regular and sweet/hot), some rags, handlebar gauntlets, tow rope and extra foam.

As was mentioned in the arcticinsider.com forum, the headlights are pointed too high from the factory and don’t have enough adjustment to lower them to the ideal position. I bent the plate against which the adjustment screws attach to effectively allow more adjustment for the adj. bolts. Worked perfectly.

Below are the set-up notes offered by Arctic Cat Product Manager Joey Hallstrom (shown here stylishly hamming it up for the camera on day 2), who raced his Sno Pro 500 to a fifth place finish in the I-500:

- Ski Springs 0703-744 (set 3/4" to 1" preload from contact of spring to the retainer. More, for rougher conditions). These are 120-lb. rate springs vs. the 145-lb. rate that comes stock. The stock springs are a bit stiff for cross country but good for snocross racing. The 120 lbs springs let the front end feel a bit softer and easier to drive.

- Front arm - Shorten to the 1st hole on the limiter strap. This shortens the travel of the front arm.  If you still need flatter cornering, drill another hole in the strap the same distance as the holes are now. There are 3 holes in the strap from production. (Set preload on the spring to 3/4" from touching the retainer. More if rough conditions).

- Rear arm - Put in the top hole in the tunnel. It comes in the lower mounting hole. Rear springs can be set per the rider weight.

- Coupling blocks at #5 setting, which should be stock.

- Overall this will lower the sled and make it better for cornering and overall handling. It won't feel as stiff and "twitchy."

- Stock clutching, stock belt.

- Engine should run 7800-7900RPM. Watch the belt deflection, if RPM drops 100-200 RPM the belt may be loose and you will need to adjust the driven clutch by bringing the sheaves together slightly.

= 6" to 8" round rod carbide runners

- 1/2 to 3/8" toe-out.

- 2 studs per bar in track

- 87 octane. DO NOT use any fuel higher than 87 octane.

- Tall windshield cut down 2" in the center only.

- Heat shield on throttle bodies needs to be secured better.

- F-series tow holds bolted to foot rests.

- Re-glue side pod and hood foam.

- Check and tighten spindles bolts after 300 miles. Same with skid frame bolts.

- Aftermarket 4-wheel rear axle setup is a good idea.