72 Mercury 500 No Spark

[RRafkin72]

It has been chewed up a bit. They should still be available

Thanks, I looked at a new one online and it doesn't look too bad comparatively. Didn't realize it's a cam

I ordered a pump kit today. Impeller was all there but definitely retired



Does the lower pump housing come out? It looks like there's a gasket below?

 

[racerone]

Bonus ,----your replacement lower unit has stainless shafts.

 

[merc850]

You pry it out with 2 screwdrivers 180* apart, there should also be an O-ring on the pump housing.

 

[jimmbo]

Unless you are getting Water in the Gearcase, I wouldn't bother removing the lower Pump Housing. If you are, then by all means pull it and replace the seals/o-ring/gasket

 

[RRafkin72]

Unless you are getting Water in the Gearcase, I wouldn't bother removing the lower Pump Housing. If you are, then by all means pull it and replace the seals/o-ring/gasket

I'm assuming it wasn't getting water in there based off of "came from a good running fresh water unit" but I'm honestly not sure.

If I get the lower pump housing off is there any thing else that comes off to do all the seals gaskets and orings?

Does anyone have a diagram of the 1970 65hp lower?

 

[jimmbo]

You will know if water is getting in when you drain the Oil. Of course, if you just bought the unit, a sharp and unethical seller, could always drain a Unit, then refill it with fresh oil, and that would hide any leaks, till after you use it. Best to get the Unit, Pressure and Vacuum tested

 

[jimmbo]

All the Seals on the Drive Shaft are in the Lower Pump housing. There are a couple more Seals on the Prop Shaft, that are in the Bearing Carrier, and there is an O-ring on the Bearing Carrier. There is also a Seal on the Shift Shaft, that pretty much covers all the Seals, except for the Gaskets on the Drain and Vent/Level Screws, and the Gasket under the Lower Pump Housing, which has that thick O-ring too

 

[RRafkin72]

You will know if water is getting in when you drain the Oil. Of course, if you just bought the unit, a sharp and unethical seller, could always drain a Unit, then refill it with fresh oil, and that would hide any leaks, till after you use it. Best to get the Unit, Pressure and Vacuum tested

Thanks I do have a pressure tester for outdrives at work and I believe a vacuum tester I'll try and snag em today...The seller said it had no oil in it when shipped, but ill pull the plug and make sure.

 

[RRafkin72]

Got the pressure tester on my new lower and heard some leakage at the lower pump housing so I tried(pryed) a little harder and got it off.



The seals are toast so ill have to get those ordered up along with the base gasket. Anyone have a diagram for the lower?

In other news I should be receiving my 65hp today at some point. So I will soon be disconnecting the 50hp and prepping for that.

Cheers, thanks again for all the tips

 

[RRafkin72]

I found a water pumpbbase gasket, and lower housing with both seals installed.

Does anyone know the part # for the lower water pump housing o ring?
Lower unit serial is 2804236

Thanks again guys