Inner & Outer Coupling won't split: Heat in the engine compartment?

[ColeHarmening]

Hey all,

Welp I have just about run through all the options as a beginner A4 mechanic that I know of to split apart my outer and inner coupling from each other. I have tried a thin saw blade, plenty of penetrating lube, multiply different thin chisels and a sledge, and a remake of Neil's Modified C Clamp coupling splitter. The only thing I can think now is to torch the heck out of it and use the chisel and hammer until it comes apart.

I have never torched anything in my engine compartment for fear of blowing my boat up. Has anyone used a torch inside their gas engine compartment? And if so what was your safety procedure? I was thinking leave as much of the engine compartment open for ventilation and then maybe put a few fans next to me blowing air away from me while I use the torch.

Also another option I was thinking through is to block the prop with a 2x4 against the hull so it can't spin, then turn the engine and put it in gear. This would force the inner coupling to spin and with the prop blocked the shaft would not be able to spin. Does that sound like it might be a smart idea that is not going to damage anything?

Thanks in advance for your ideas.

[Dave Neptune]

I don't think blocking the prop and spinning the motor is a good idea as you could bend the prop or the shaft which would not be hard to do.

Are you blocking the coupling from the underside so the "shock" is concentrated on the coupling and not being absorbed by the shaft? The hammer strikes need to be solid as possible.

Did you try a knife edge? A stainless steel knife is not as hard as a carbon steel blade however it is far tougher for your needs. The sharper the "chiseling object" is the more outward leverage the blows will have.

Dave Neptune

[hanleyclifford]

Try a small propane torch like you might use to sweat copper pipes. Have extinguisher handy.

[ColeHarmening]

I got it off finally! Thanks for the suggestions. I ended up grinding down a fine edge on my cold chisel and banging that with a sledge hammer finally broke it lose.

[hanleyclifford]

Clean it real well, paint, and apply layer of grease or oil on reassembly.