1988 mercery 175: Poppet valve

The install seems preaty straight forward on the Poppet.
First let me start off in saying when I took the cover off I had a lot of salt water corrosion on the inside of the cover that touches the gasket.
Second from what I have read this was supposed to pop out since it is spring loaded. It did not. It is stuck so as you know if you investigate any further you are replacing the whole set up in which I ordered one.
I am thinking this is either stuck shut or stuck open that is why It will not pop out. After prying a little on the inside diaphram I tore a little hole in it.
So my symtoms before I investigated the popett valve were blowing steam out of my teltale hose. The thermostatts are new and not defective and my water pumps seems to pump strong (bought another just in case I could always replace it anyway). starts steaming in idle gear when I come in the dock area causing it to start to overheat.

Re: 1988 mercery 175: Poppet valve

Poppet stuck open would do that. The water drains out the bottom and doesn't fill the block and the top part overheats.

go for it
John

Re: 1988 mercery 175: Poppet valve

Double check but I'm pretty sure the top popet cover only exposes the diaphram there is a second plate that needs to be removed to actually get the poppet out. Corrosion may be keeping it from comming free.

Re: 1988 mercery 175: Poppet valve

Thanks for the replies. I just got the parts today so looks like some Saterday work for me. You are correct there is a plate behind the diaphram. By the way nice tear down good luck with that. I come accross a few motors like that one in the sarasota area the 1990 200 black max I looked at was like new guy was asking 1250 I thought real hard on that it was off a early 90s ranger not a good boat for Florida tho. I have a 98 Campion 622 WA (heavy boat). I think I am a little underpowerd I would like to put a 200hp on it cause the old 175 actually runs like a 150 since they rated the hp off the flywheel back in the day. Off the prop is going to be a bit less.