I gave my new 390XP a real high altitude workout this week. I am located in Utah and we have some spectacular forests in Utah known as the Uinta-Wasatch-Cache National Forest. As with much of the western US, we have been hit hard by the Mountain Pine Beetle. Some areas are experiencing a significant epidemic, where Mountain Pine Beetle populations have killed up to 90% of trees within infected stands.
I was in the Mirror Lake area of the Uinta Mountains at approximately 10,000 feet of elevation. I was asked to help out with felling some beetle-killed trees. I ran a 32" bar with full comp chisel chain. Most of the trees I felled were 28" to 36" DBH. In a day and a half, I felled over 30 trees. No limbing or bucking, just felling.
The elevation was killer. I have never been so damn tired. The saw performed better than I expected for the elevation. I tuned the saw for 4,000 feet and that's the tune I ran at 10,000 feet. Yes, it ran a bit rich, but I forgot my tachometer, so I decided not to fiddle with the carb settings. Ambient temperature ranged between 50 - 60 degrees F. Based on how the saw performed, I estimate that usable horsepower was down by 25% to 30%. Not too bad, but I could tell that the saw seemed to be laboring much more than I expected. I couldn't run the dogs into the tree and lever hard into the cut. The saw bogged down unless I backed off. End of the day, it felt like I as running a 372XP at lower elevation -- but I had all the weight of the 390 and 32" bar.
No doubt that the saw really could have used a "woods port" to help it breath better. That is likely my next step.
The sight of so many beetle killed trees was devastating. Felling trees and leaving them where they fell and moving on to the next was a little surreal. I've been asked to come back ASAP and the plan is to gather up a group of fellers to accompany me in a few weeks.
JQ
I was in the Mirror Lake area of the Uinta Mountains at approximately 10,000 feet of elevation. I was asked to help out with felling some beetle-killed trees. I ran a 32" bar with full comp chisel chain. Most of the trees I felled were 28" to 36" DBH. In a day and a half, I felled over 30 trees. No limbing or bucking, just felling.
The elevation was killer. I have never been so damn tired. The saw performed better than I expected for the elevation. I tuned the saw for 4,000 feet and that's the tune I ran at 10,000 feet. Yes, it ran a bit rich, but I forgot my tachometer, so I decided not to fiddle with the carb settings. Ambient temperature ranged between 50 - 60 degrees F. Based on how the saw performed, I estimate that usable horsepower was down by 25% to 30%. Not too bad, but I could tell that the saw seemed to be laboring much more than I expected. I couldn't run the dogs into the tree and lever hard into the cut. The saw bogged down unless I backed off. End of the day, it felt like I as running a 372XP at lower elevation -- but I had all the weight of the 390 and 32" bar.
No doubt that the saw really could have used a "woods port" to help it breath better. That is likely my next step.
The sight of so many beetle killed trees was devastating. Felling trees and leaving them where they fell and moving on to the next was a little surreal. I've been asked to come back ASAP and the plan is to gather up a group of fellers to accompany me in a few weeks.
JQ
