water indicator slow then stop

[bigheaded5]

Today was the first time taking my Evenrude 90 VRO (1985) for a spin. I bought it used, it runs strong and everything worked great. About a half hour into the trip, the water indicator slowed down then stopped. It began again but stopped shortly after completely.

It appeared to me that something might have gotten caught in the exit tube. The engine remained fairly cool by the time I got back to the ramp. Yes, i turned around as soon as I noticed the water jet slowing down. I wanted to make sure the engine didnt have any issues before replacing the impeller. It was pumping strong at home, so I figured an hour on the water would be fine. ALSO..when I ran the motor clean when I got back, the stream was STRONG again.

Aside from blowing out the tube with a shot of air and changing the impeller, is there anything else i should look for? I am assuming the flow to the heads was fine the entire time because the motor never got too hot to touch.... how HOT is HOT?

 

[emdsapmgr]

Re: water indicator slow then stop

It's not unusual for the telltale nozzle in the lower cowling to plug up with sand, debris. It will stop the flow through the nozzle. It does not impede the cooling of the powerhead if that happens. Blowing compressed air up the nozzle or using the string from a yard trimmer will work to clean out the nozzle. The thermostat housing is the last thing the cooling water goes through before it exits down the the midsection. If the stats are working, the powerhead will cool normally. Those stats will regulate the powerhead temps between 145 and 150 give or take. An overheat horn sounds at 212 and stays on till the powerhead cools back down to 175-still to hot for normal running. A simple laser temp gun aimed at the heads will show you the tru temps. On the other hand: if the stats stick open, the powerhead will run cool-not a good thing in the long run, as those cooler temps cause carbon to accumulate around the ringsets and piston skirts. Fuel economy will suffer slightly.

 

[bigheaded5]

Re: water indicator slow then stop

Thank you chock full of info!

 

[bigheaded5]

Re: water indicator slow then stop

Thanks again...I explored the engine a bit and found the sending units on each head. I metered them referencing to ground, then grounded each sensor confirming the warning horn works. Its a BIG relief knowing that the sensors will trigger the horn when there is trouble with the temp!

 

[bigheaded5]

Re: water indicator slow then stop

The next day I blew out the telltale line into a clean white tub...and there was a bunch of sea grass that came out.... That problem fixed.