First we have to understand that if the chain is prevented from moving but the throttle is asking the engine to rev up, the clutch will be slipping and all the power that the saw is making will show up as heat in the clutch.
1. Warm the engine up by leaving it run at fast idle with the chain brake on.
2. Chain brake gets accidentally tripped and the operator thinks there is something wrong with the engine because it won't rev up and he keeps trying to make it rev. Happens more often now with newer saws having brakes that are sensitive to bar tip impacts.
3. Operator is cutting and puts so much pressure on the bar that the chain stalls so he backs off a bit until the chain gets cutting again, then10 seconds later he does it again. Repeat. You can tell Bubba is using a chainsaw by the sound of the engine.
4. Same as #3 except the chain stalls because the engine has lost power and won't pull much of a load.
5. Saw has become stuck in the cut and the operator spends 5 minutes pushing, pulling and twisting with the throttle held open, hoping he can get the chain moving and cut the saw free.
6. Chain doesn't want to move because it's too tight, tip sprocket stuck or bar grove filled with gunge, the clutch has to do a lot of slipping until the engine reaches an rpm that is high enough to tighten the clutch enough to get it moving.
Anyone who is skeptical about clutch heating should try to rev a saw for 10 seconds with the brake on and then put a finger on the clutch drum. Wet the finger first.
1. Warm the engine up by leaving it run at fast idle with the chain brake on.
2. Chain brake gets accidentally tripped and the operator thinks there is something wrong with the engine because it won't rev up and he keeps trying to make it rev. Happens more often now with newer saws having brakes that are sensitive to bar tip impacts.
3. Operator is cutting and puts so much pressure on the bar that the chain stalls so he backs off a bit until the chain gets cutting again, then10 seconds later he does it again. Repeat. You can tell Bubba is using a chainsaw by the sound of the engine.
4. Same as #3 except the chain stalls because the engine has lost power and won't pull much of a load.
5. Saw has become stuck in the cut and the operator spends 5 minutes pushing, pulling and twisting with the throttle held open, hoping he can get the chain moving and cut the saw free.
6. Chain doesn't want to move because it's too tight, tip sprocket stuck or bar grove filled with gunge, the clutch has to do a lot of slipping until the engine reaches an rpm that is high enough to tighten the clutch enough to get it moving.
Anyone who is skeptical about clutch heating should try to rev a saw for 10 seconds with the brake on and then put a finger on the clutch drum. Wet the finger first.
