Evinrude 225 Engine Problems

[robayles]

My engine is a 1997 Evinrude 225 Ocean Pro. Today I took her out for the first ride of the spring. We were at 4800 rpms when the temp. alarm came on. I just had the waterpump and impeller replaced and the water stream was strong and cool. I idled until the alarm went off and tried again. When I got over 2000 rpms the boat ran really rough. If I kept it at 1200 rpms it was fine. Between 1200 and 2000 rpms the alarms went off again.<br /><br />Any ideas what may be wrong?<br /><br />Thanks,<br /><br />The Big O

 

[Dhadley]

Re: Evinrude 225 Engine Problems

First, welcome aboard.<br /><br />When the overheat occured, the motor probably went into SLOW (speed limit overheat warning) which limits the rpms to around 2500 or so. To reset SLOW you must stop and sut off the motor. You said you slowed down but never shut it off. Most likely it was still in SLOW mode.<br /><br />However, we need to find the cause of the alarm. If the pump was just serviced, and this never happened before, thats a good place to start.<br /><br />What was the water pressure?

 

[robayles]

Re: Evinrude 225 Engine Problems

Thanks for your comments. That seems to make sense about the inability to get above 2500 rpms. I talked to a mechanic today and he said that it probably is related the the thermostat. I'm going to have it looked at tomorrow.<br /><br />Thanks again.<br /><br />The Big O

 

[clanton]

Re: Evinrude 225 Engine Problems

Insure the correct water pump was installed.

 

[clanton]

Re: Evinrude 225 Engine Problems

Waterpump pn 5001595.

 

[robayles]

Re: Evinrude 225 Engine Problems

Thanks everyone for their comments. I had a mechanic go out on the boat with me. Luckily the same chain of events happened. The boat got up to about 4000 rpms and the alarm came on. The boat went into SLOW mode and we took it back to the dock. The mechanic did a compression test, 120,120,120,120,120,100. One was a little low but he didn't think that would be the cause of this.<br /><br />He took out the thermostats and one was open and one was closed. One side of the motor was hot and the other was okay. <br /><br />We took the boat out without the thermostats and without the temperature alarm sensor attached and the motor ran great. We put the sensor back on and it was fine. Diagnosis, the other mechanic who had replaced the water pump and impeller had used an aftermarket thermostat that was the wrong size.<br /><br />I took the boat out the next day (after the thermostats were replaced). We had just idled out of our slip and down the canal, just passed the no wake zone marker when I gave it some gas and immediately the alarm came on.<br /><br />Any thoughts what may be happening? The second mechanic is coming back out Monday. He thinks it may be a bad sensor. Any thoughts or advise will be greatly appreciated.<br /><br />Thanks,<br /><br />The Big O

 

[clanton]

Re: Evinrude 225 Engine Problems

If the wrong thermostat was installed, how do you know the correct waterpump was? If 5 of the cylinders have 120 psi compression, the 1 cylinder with 100 lbs is low and will become a problem. Ater the over heat is solved, do a decarb with Johnson engine tuner and recheck the compression.

 

[robayles]

Re: Evinrude 225 Engine Problems

Clanton, you make a good point regarding the water pump. If the sensor is not the culprit we'll check that as well.<br /><br />The decarb is next on the list.<br /><br />Thanks,<br /><br />The Big O