I had the same problem. No clutch on the motor. I changed the gear #226053-3A and the two plane bearings # 214019-5 that support it. Just enough wear on the gear and a little looseness on the bearings made the gears jump. The saw works fine now.

You have to remove all the exterior attachments with a Phillips screwdriver and an Allen wrench. Hold the saw in the blade down position and roll the upper part of the housing off. The switch stayed in the upper half of my saw. One side of the switch has a spade connector and the other one is soldered to the battery holder. I found it easier to do with the motor out of the housing. Once the motor was back in place the rest practically fell back in place. The only problem I encountered was with the blade guard which I took completely apart to clean. The inner ring is out of round and I'll have to order a new one. The new switch works great, I really don't know why I waited so long to replace it. I really like this saw!!