No water from exhaust

[Tumpaa]

Hi,<br /><br />Have a problem with Johnson OB, FD-18 -64 model.<br /><br />There is only little mist coming from exhaust when running. Changed impeller wheel. When taking thermostat away there was normal amount of water coming from exhaust relief port. Seems that bypass circulation system is blocked somewhere. Has anyone any idea where to search the plockage??<br /><br />Thermostat is woking good as motor was running normal temperatuere and water was coming out from exhaust when it opened. When thermostat removed motor was running too cold.<br /><br />Tumpaa

 

[Joe Reeves]

Re: No water from exhaust

Trumpaa.... Replace the entire water pump assy (#382468) and seal it as follows:<br /><br />Any gaskets (unlikely in that kit) should be coated with Gasket Sealer (the type that comes in a can that has a small brush in its screw off cap).<br /> <br />Sealer 1000 or OMC Adhesive (same substance) should be used on any metal to metal or metal to plastic surface (such as impeller hsg to plate) to eliminate air leaks. Sealer 1000 may also be found in other brand names such as "Boat Armor" but the name of Sealer 1000 will always be mentioned on the tube.<br />-------<br /><br />While the lower unit is off, use pressurized air to blow up the water tube, and down through the thermostat opening to insure there's no blockage.<br /><br />Check compression. If faulty, there's a posibility that the head gasket is failing which would allow combustion to enter the water passageways. This result in a stalemate, causing the engine to overheat.

 

[Tumpaa]

Re: No water from exhaust

Thanks for you repply. I get good waterflow without thermostat. Do you thing that it is still the pump?<br /><br />Tumpaa

 

[Joe Reeves]

Re: No water from exhaust

I just re-read your original post. You say that water flows out the exhaust relief when the thermostat opens, and that the thermostat is okay. If this is the case, and the engine doesn't overheat, I wouldn't be concerned about it.<br /><br />Apparently I miss-read it previously and was under the impression that water did not flow out the exhaust relief regardless of the thermostat being open or not.

 

[Tumpaa]

Re: No water from exhaust

Water is circulating ok when no thermostat but I thing that it is running way too cool. If I but the thermostat back then motor is not getting hot, but upper exhaust leg is getting very hot from lack of water. There is only mist coming while thermostat is closed and exchaust is sort of steamy. When thermostat opens then upper leg is cooling down and steam dissapears. Where to seach bloggage?<br /><br />Tumpaa

 

[ledgefinder]

Re: No water from exhaust

How hot is 'hot' on that exhaust leg? The thermostat opens at something like 145 degrees F, which is pretty warm.

 

[Tumpaa]

Re: No water from exhaust

Some of that water (mist) is turning to steam while thermostat is not open. Thats how hot it is.<br /><br />I think that fine mist is circulating only via thermostat little hole that is some sort of bypass for thermostat. Should I make that hole bigger to get more circulation while thermostat closed?