Try putting in new aluminum clutch shoes. They are pretty much the same weight as the stock plastic ones. I couldn't tell much of a difference when I held them. When you go to put on the new springs. Soften them up first. Take two pair of needle nose pliers and move them in the same fashion they would if they were engaging. This will help your truck engage quicker. Also it will be three new springs that you know are good.

You don't have to soften up the springs, but if you like torque in your rc this will help. Keep in mind this might not be the best choice for you, but its an option.

I don't think the one way bearing is causing your problem. It could possibly be in the tranny. I would tear the clutchbell of and inspect it for unusual signs, then go to the spur gears and inspect everything their. If all else fails. Call losi before you rip into the tranny. Maybe they can help you. I called them today and they are sending me a new OWB.

Those are my thoughts and I'm probably wrong.