850 Patriot Engine Refinements

Right out of the gate, Polaris has told us all along that the number one goal with their new 850 Patriot engine was to provide extreme durability. This is why they took the “clean sheet” approach to the engine development and looked at so many different combinations, designs and configurations. They firmly believe the architecture they selected is totally up to the task.

That’s why last winter, when there were some isolated issues with a small number of the 850 Patriot engines, Polaris engineers took it to task. They were extremely proud of their new engine and the very last thing they expected or wanted was for something to go wrong, no matter how small or insignificant. What had they missed?

Analyzing the data they identified four issues that could be improved upon. First was PTO bearing movement in the crankcase. To remedy this they have now a new PTO bearing with a retaining ring to positively maintain its proper position in the crankcase. Additionally, they’ve changed the machining process for the crankcase to accommodate this new positioning ring on the bearing.

Next was with the application of silicone sealant to the crankcase halves during assembly, where too much sealant was being applied and some of this excess made its way into a check valve. To remedy this, they’ve improved the manufacturing and assembly process for crankcase sealant application and have added a new screened internal check valve to the center cavity to catch any excess sealant.

There were some issues with hot starts, as well as some slight bogging and hesitations when one would get out of the throttle and right back into it again. To remedy this, the ECU calibration has been enhanced with control and software improvements. The same ECU mapping will be used across all 850 models for 2020, and MY19 sleds can also have the 2020 software installed – via reflash.

There were also some other detail changes. The piston profile was tweaked for improved heat tolerance. The 850 gets a new water temp sensor. There is a new oil feed feature for the center main bearings, and we find new larger mag side engine mounts.

Let us remind you that it is very common for a manufacturer to make similar changes and enhancements with each year’s build of engines, and machines. Constant evolution is always happening. Some of it is a reflection of trying to improve durability, some of it is to reduce warranty costs, and yes, sometimes it happens to reduce production costs. In the case of the changes to the 850 Patriot engine for 2020, it appears to all be an attempt to make a great engine even better. Remember, Polaris offers a 4-year warranty on this engine, both for 2019 and 2020. They wouldn’t do that unless they knew they had a great product to stand behind.