58 35 hp johnson thermostat?

PJHawkins

Cadet
Joined
Feb 28, 2003
Messages
13
I've just replaced my impeller. Now for some reason I am not pumping water at all. I have pulled the lower unit a half dozen times already to no avail. I have been reading alot about a thermostat but have seen nothing that even resembles such a thing on my unit, (Super sea-horse). Should I be pulling the soft plug above the exhaust?
 

CATransplant

Admiral
Joined
Feb 26, 2005
Messages
6,319
Re: 58 35 hp johnson thermostat?

If your engine doesn't have the cream-colored and gold hood, it doesn't have a thermostat. Only the Super Seahorses of that year incorporate a thermostat. On those models, the thermostat is under a cover with three screws on top of the engine.<br /><br />Did you make sure the key that drives the impeller was in place when you installed the impeller? If not, then the impeller won't turn.
 

PJHawkins

Cadet
Joined
Feb 28, 2003
Messages
13
Re: 58 35 hp johnson thermostat?

Yes the motor is a super sea-horse. The pump works fine when I take off the lower unit and turn the shaft in water but for some reason it does not get to the block. I've checked for blockage and all is clear.
 

nimmor

Petty Officer 1st Class
Joined
May 15, 2003
Messages
313
Re: 58 35 hp johnson thermostat?

I have a 1959 35 super seahorse which should be pretty much like yours. The thermostat is inside a little semi domed housing with three screws on the back of the engine at the top of the head.
 

PJHawkins

Cadet
Joined
Feb 28, 2003
Messages
13
Re: 58 35 hp johnson thermostat?

I have determined I have no thermostat. But for the life of me I cannot figure out why that darn thing will not pump water to the power head. I have tried everything, (Except for the cure). I have talked with mech. at the local marina and he too is at a loss.
 

Paul Moir

Admiral
Joined
Nov 5, 2002
Messages
6,847
Re: 58 35 hp johnson thermostat?

Are you operating it in water deep enough? The water line should be up above the water pump for it to prime.<br /><br />Oh, one big question! There's two impellers for '58 35hp engines - ones for thermostated ones and ones for those without. What part number impeller did you get??<br /><br />(The thermostat should be really obvious. It should be under the plate at the top of the 'stand pipe' on the starboard side of the head. If none of that makes any sense, you don't have one)<br /><br />EDIT: (Even more obvious, you would have noticed there's two copper water tubes in the thermostated engine and only one in the non-thermostated :) )
 

krb113

Petty Officer 3rd Class
Joined
Jan 19, 2005
Messages
89
Re: 58 35 hp johnson thermostat?

Just went thru this on my 40 hp Ev. Check your compression and see if it is o.k. Mine turned out to be a blown head gasket. Put a new one on and I am now back to pumping water. Nearly drove me to dry land!!
 
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