Exhaust Megaphone

I recently had problems with

I recently had problems with my 175 Evinrude where a piece of engine debris was stuck inside the prop Hub and stalled the engine. I removed the prop and this piece of metal and started the engine. It runs great. I've been told that this piece of metal is part of the "Exhaust Megaphone". I want to know if I can/should remove the exhaust cover and see the extent of the damage and if so is it a difficult job. I notice that the water indicator pipe comes out of the cover.

" Gora,

That can be a diffi

" Gora,

That can be a difficult job. You may have to remove the power head to do it properly. On the other hand, I know of a few engines with the same problem, and they continue to run well. I think the best bet is to leave it until you are ready to rebuild the powerhead completely. Then you can deal with it properly. I don't think there is any other damage to the engine; just insure that the exhaust is cooling properly.

Tony "

"Gorazd.... That interior port

"Gorazd.... That interior portion of your engine where the water telltale outlet hose attaches, contains the inner baffle plate assy, or inner exhaust cover as OMC calls it, not the megaphone. The megaphone is a item that is located under the adapter plate that the powerhead bolts to, and this item is even more difficult to replace than the inner exhaust cover. It would be necessary to remove the powerhead and the lower unit, then remove the exhaust housing (the section between the powerhead and the lower unit) from the transom brackets, then dismantle that exhaust housing completely to reveal the megaphone. It's quite an ordeal. As Tony has mentioned, many engines run fine even though this item is damaged, and if this is the case, wait until the removal of the powerhead is needed for some other reason. However, a word of caution.... usually these items fail due to a fine spray of water being injected into that area from some source such as a failing gasket in the adapter plate or elsewhere. This fine spray of water, if it exists, coupled with the violent explosions being forced out of the combustion chambers, creates a destructive power such as that of an acetylene torch. With that in mind, pay particular attention to your spark plugs, especially in the lower cylinders for traces of water, or what may appear to be a tiny, hard, ball like substance on the electrodes.

Joe "

" Joe,
I've had good luck

" Joe,
I've had good luck using the motor w/ the damaged megaphone for a couple of seasons BUT as I was flushing-out the motor, I noticed water leaking out from under the exhaust cover I think maybe it's what you describe as the adapter plate. The exhaust cover is fine but where the powerhead bolts to in the back bottom (actually behind the bolt there's a hole). Sounds like your acetylene torch description may have eaten away at it.
I'm reading compression around 90 all round, it starts-up good but considering the exhaust megaphone problem and that the lower unit is original, I think the party is over. "