Polaris Pro-R 600/800 CFI Airbox Mod
A great modification to get more air, and more power is to modify your airbox. Pull the cover off the box and inside you will find a shelf like the one pictured below. Remove this shelf replace it with our BMP High Flow Pro-R Shelf. We found holes in the top side of the shelf like shown worked out the best; gaining you 3 horsepower through mid to peak. Some may think more is better and want to add holes in the bottom side of the shelf also. We advise to not do this! This creates a strange flow wave in the airbox and only gains 1hp. Removing the shelf all together gained 1.5-2hp. No fuel modifications needed on a stock or slightly modified machine, just cheap and easy horsepower! Click the picture below to purchase this airbox shelf.
Polaris 800 CFI Low Compression
Have a Polaris 800 CFI snowmobile? Be sure you do a compression check! These motors have quite a bit of rod angle and are known to wear out rings & pistons fast! Your motor should have at least 125 psi of compression (make sure you hold the throttle wide open!) on a known good gauge. We have seen many sleds around the 2000 mile mark with low compression that do not make peak power. If you are around this milage keep an eye on your tach as this is a good indication of a weak motor. A motor low on compression will be a few hundred rpm short of peak rpm.
FIX IT! Now we have our Durability Kit which uses a cylinder spacer with taller pistons with slightly further spaced rings. This really helps the motor be more reliable, live longer, and even gains 5-6hp with no fuel controller! This kit also now comes with our big bore packages... thats right... big bore and reliability! See the durability kit by clicking HERE
Polaris 800 CFI Oil Pump Adjustment
Yet another problem easily fixed with the Pro-R 800 CFI!! They are run very lean on oil from the factory, which can be costly especially when running mods where you are adding extra fuel. With big bores we even recommend pre-mixing your fuel at 100:1 in addition to this adjustment. We recommend turning the pump up 3 full turns on a big bore, 1.5 turns when adding fuel with a controller, and even 1 turn for stock machines. Here is a great video on how its done for big bores!