Lionel 8041-50 Smoke Unit

It does fit the Lionel 246. I tried again, tight fit. The bellows paddle fit and gets pushed by the slide rod as it should. This 8041-50 Smoke Unit was bought from Ebay, it has a has its own light which uses a wedge base bulb. Since the motor in the 246 also has a bayonet socket I decided to use the one on the smoke unit instead. I broke the glass bulb on the bayonet bulb and removed everything on the inside of the brass socket. Then I soldered the lead from  the smoke unit that didn't have a spade clip inside with some heat insulation I took from a yard led. The brass base was cut down to about half of it's original length with a pair of aviation shears. The ground wire with the spade clip I attached to the slide rod holder with one of its screws. It all fit back inside and the light works and paddle moves the bellows. I had to seal the holes where the resistor leads go in and cover the bellows with the finger tip of a surgical glove. These plastic units leak as much smoke from these 3 areas as comes out the stack. The stack was cut down by about 3/8" and a piece of vinyl tube about 1/2" slide over the stack by shaving down 4 plastic ridges on the stack. this made up for a slight misalignment of the Locomotives stack with the smoke units. I hope this will help someone else.