High All,
I'm new to the forum (in terms of registering and posting anyway, I've been reading the forum on and off for a little while). I grew up snowmobilling, with my family having machines when I was a kid. Life and career came up, though, and took me around the world. I quit riding right after high school. Back in 2018 I retired and moved back to Northern Utah. I always enjoyed snowmobilling and eventually I bought a couple of older machines and started riding again. It didn't take long for me to realize that things had changed quite a bit in the snowmobile world, and although the machines and style of riding was different, I still enjoyed it. I started to try to become better at it. I eventually decided that the (real) old machines weren't going to cut it for me so I upgraded a little and bought a 2016 Polaris Pro RMK 800. In many ways I was still pretty ignorant of newer snowmobilling information and technology and I hadn't progressed in my skills enough to understand where I wanted to go with this hobby (If I had been more informed, I'd probably have bought a newer machine). At any rate, I've ridden the RMK for about 2 years and it's performed pretty good. This year I decided to go up to Island Park and take a couple of days of instruction at Brett Rasmussen's school. It was awsome, but after the first day, on the trail ride back to the hotel, my machine started acting up. It started to cut out at high RPM, and by the time I got back to the trailer, it started backfiring through the exhaust and idled at 3500 rpm (which wouldn't allow it to go into reverse). I ended up riding one of the school's machines for the second day. Now the RMK starts fine, and runs normal until the throttle is triggered the first time, afterwhich it stays at the 3500 rpm and backfires occasionally. I'm a cetified aircraft mechanic, and I've even spent some time as a mechanic at a powersports dealership (although I did it to learn and I'm still pretty inexperienced with snowmobiles). I thought about trying to tear into the machine an try to fix it myself but I knew it would take me awhile to figure things out and I didn't want to miss the riding this season. I decided to take the machine to the local Polaris dealership near my home. They had a little trouble figuring it out but they're now telling me that the problem is a leaking crank seal which will require them to split the case of the motor to replace (they did give me a pretty reasonable estimate to do the work though).
The machine is coming up on 2000 miles, and I have read that these Polaris 800s often have problems at about this time (needing a top end rebuild and such). I checked the compression on the machine and it's lower than I'd like (about 105 on one cylinder and 110 on the other) but I did cylinder leak tests on both sides and the tests turned out good. My question to the forum is (all of you who are much more knowledgable than I), since the engine will need to be removed to fix the crank seal, would I be smart to go ahead and just do a complete overhaul to the engine, check the reeds, the power valves, replace motor mounts and such? If it were smarter to do the bigger job, I'd probably go ahead and do the work myself but if I was just going to have crank seal repaired, I'd probably have the dealer do the work. Also, I'd be interested in recommendation on where to get a good overhaul kit and such. Any wisdom you all could provide me, would be greatly appreciated. Thank you
I'm new to the forum (in terms of registering and posting anyway, I've been reading the forum on and off for a little while). I grew up snowmobilling, with my family having machines when I was a kid. Life and career came up, though, and took me around the world. I quit riding right after high school. Back in 2018 I retired and moved back to Northern Utah. I always enjoyed snowmobilling and eventually I bought a couple of older machines and started riding again. It didn't take long for me to realize that things had changed quite a bit in the snowmobile world, and although the machines and style of riding was different, I still enjoyed it. I started to try to become better at it. I eventually decided that the (real) old machines weren't going to cut it for me so I upgraded a little and bought a 2016 Polaris Pro RMK 800. In many ways I was still pretty ignorant of newer snowmobilling information and technology and I hadn't progressed in my skills enough to understand where I wanted to go with this hobby (If I had been more informed, I'd probably have bought a newer machine). At any rate, I've ridden the RMK for about 2 years and it's performed pretty good. This year I decided to go up to Island Park and take a couple of days of instruction at Brett Rasmussen's school. It was awsome, but after the first day, on the trail ride back to the hotel, my machine started acting up. It started to cut out at high RPM, and by the time I got back to the trailer, it started backfiring through the exhaust and idled at 3500 rpm (which wouldn't allow it to go into reverse). I ended up riding one of the school's machines for the second day. Now the RMK starts fine, and runs normal until the throttle is triggered the first time, afterwhich it stays at the 3500 rpm and backfires occasionally. I'm a cetified aircraft mechanic, and I've even spent some time as a mechanic at a powersports dealership (although I did it to learn and I'm still pretty inexperienced with snowmobiles). I thought about trying to tear into the machine an try to fix it myself but I knew it would take me awhile to figure things out and I didn't want to miss the riding this season. I decided to take the machine to the local Polaris dealership near my home. They had a little trouble figuring it out but they're now telling me that the problem is a leaking crank seal which will require them to split the case of the motor to replace (they did give me a pretty reasonable estimate to do the work though).
The machine is coming up on 2000 miles, and I have read that these Polaris 800s often have problems at about this time (needing a top end rebuild and such). I checked the compression on the machine and it's lower than I'd like (about 105 on one cylinder and 110 on the other) but I did cylinder leak tests on both sides and the tests turned out good. My question to the forum is (all of you who are much more knowledgable than I), since the engine will need to be removed to fix the crank seal, would I be smart to go ahead and just do a complete overhaul to the engine, check the reeds, the power valves, replace motor mounts and such? If it were smarter to do the bigger job, I'd probably go ahead and do the work myself but if I was just going to have crank seal repaired, I'd probably have the dealer do the work. Also, I'd be interested in recommendation on where to get a good overhaul kit and such. Any wisdom you all could provide me, would be greatly appreciated. Thank you
