The original horizontal windlass to our boat, since replaced, had no power out capability either. Deployment speed was regulated with a large, bronze wheel that put pressure on a pair of clutch plates, one bronze and the other a fiber material, that pressed against the outboard surface of the wildcat. It did the same thing you describe to the point where I had to help the chain out even with the brake backed off. Finally I decided to do something about it, and it was a simple matter to remove the brake wheel, clutch plates and wildcat and clean the old, gummed up lubricant from the wildcat and its drive shaft, apply fresh grease, and put the thing back together. That solved the problem.
The new horizontal windlass we installed about three years ago has a different type of brake system.* A small brake wheel applies pressure to a cone clutch rather then flat friction plates like the old windlass had.* It's my understanding that friction plates are not supposed to be lubed, particularly fiber ones, but the manual for our new windlass says the two (metal) surfaces of the cone clutch should receive a very light coating of grease every so often.
I assume the wlidcat on your windlass is turning to let the chain out, it's just not turning very freely.* If so, I would not be surprised if all it needs is either a refresher coat of grease or a cleaning off of old, gummy lubricant and a fresh application of grease.
-- Edited by Marin on Wednesday 14th of April 2010 01:00:18 PM