Logo
FULL SITE MENU

1991 Johnson V4 Cooling

R

Rick_B

Member
So I'm finally getting to the point where I can put my new to me starcraft 19' deep V with a 1991 Johnson V4 in the water. Because it s new to me I wanted to start it out of the water first using a flushing device (earmuff). The motor started fine however there was no water being ejected at the top of the engine. I immediately turned the engine off and let the water runnng through the flushing device. I did see a stream of water coming from a small hole behind the intake grill and what I think was another stream from behind the engine and a little hogher than the intakes.

My immediate thought was oh %$^%(@ - wat I have got myself into now. Then I pulled out my spanking new service manual and did some reading. I did find a section where it was noted that the powerhead has thermostats that prevent water from flowing into the powerhead until it comes up to operating temperature. I also saw that there was some discussion about a pressure relief valve.

So I'm wondering how long it would take for the thermostat to open up and allow cooling water into the powerhead and out of the ejection tube? Secondly, are the streams of water I see from holes in the lower unit because of a bypass/pressure releif until the powerhead thermostats engage.

Thanks
Rick
 
Don't believe you ran it long enough to get the stats to open; take the hood off while you are running on the muffs put a few drops of water o the heads if it overeats the water ill boil. Water should exit thru the prop exhaust and a mist thur the exhaust relief holes up the top of the leg. Hang I there the gurus do not say on this site the whole time but they should chime in. good luck
 
Since it is new to you do you have any idea when the water pump impeller was last replaced? If you don't know I would replace it with the correct water pump kit so you know what you have. If the engine has been setting a long time the thermostats could be stuck or plugged up. I'd pull them out to clean and test them.


When running on muffs resist the urge to run the motor at high rpms. I never go much above idle. You just don't have the same cooling capability using muffs that you do with the water pump properly submersed in water.

Look up the model number and use the correct parts diagram to get the part numbers so you can order.
http://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1991&hp=120

Bill
 
Thans guys - even though the engine is new to me I did see it run when I bought it and I did have a marina check it out but it has been a number of weeks since that has occurred. Thid morning I took a deep breath and tried the engine again. I left it running for a bit lnger and YAHOO water started to discharge from the power head end. I think I am now ready to get this in the water.

Rick
 
Back
Top