We were at the hotel at Pet by 2:30. Although I did tow a guy down by Pembroke, to his house only about 200 yds near the B100A and TV Tower Road. Having done this for 27 years, myself having had two pistons in 3 years blow on my 600SDI, and soon after two other 600SDI in our group blow pistons, back in our 2-stroke days (never again), i always have a two strap and a sled tow harness with me (for other riders so far, thankfully).  My annual day trip to Pembroke (trailer from Ottawa)  and ride out to Spectacle Lake lodge trip has now been replaced by Petawawa and those trails north (13* and 19*).

https://www.sootoday.com/city-police-beat/opp-officers-undergo-snowmobile-training-to-boost-winter-patrols-11835025

The maintenance was at 500 kms  for chain case oil, spark plug replacement, belt replacement, etc, nothing noted on the Dynamic.    Etech plugs are good for 3 yrs or 10,000Kms, chain case oil basically once per season.   Was told on the Polaris I should consider changing the belt at 2,500kms.    

SOLD

At about 2:30 PM, we were through the 131 intersection that you mentioned, but we weren't the group you saw. We were a group of only 3, 2 black MXZ 900 n/a Skidoos and a blue Apex. Without being crowded, the trails were well populated on Friday with solo riders to large groups and all sizes in between. We even saw two sleds being towed, which was a bit of a curiosity to our noobie on the Apex. He asked if that is a common occurrence? LOL. My main riding buddy and I have ridden those trails since late in the last Millennium, and Wed - Friday were the best trail conditions, with good weather, that we have ever experienced from Deep River to just east of North Bay. What a joy it was to be out! Sounds like you had a good time too.