225 Evinrude Mystery

[bradenton_whaler]

I have a 1994 225hp Evinrude OceanPro with 160 hours on it. The compression check out at 120 at each cylinder. I recently purchased the boat and am working the "bugs" out. I have replaced the water pump, fuel pump, and thermostats. The carbs were cleaned and the 70-gal tanks were drained (placed with 5 gal each then redrained).<br /><br />She actually runs great for the first 5 minutes; on a plane and actually cruising at a good speed (33-40 mph). Then she puts herself down to the 2,500-3,000 rpm range (slow mode) but when in nuetral will rev up normally? What else can I do to solve this problem? Somebody mentioned the power packs but I do not know what this does or if it can be the problem. Please advise.

 

[ob]

Re: 225 Evinrude Mystery

bradenton_whaler,When your engine kicks into slow mode as you describe are you getting an alarm?Also when key is initially turned to on position do you get a short tone which verifies alarm horn is working?

 

[bradenton_whaler]

Re: 225 Evinrude Mystery

No alarm, either way. When initially purchased, the alarm was sounding. I had the VRO disconnected and the mechanic forgot to disconnect the alarm.

 

[ob]

Re: 225 Evinrude Mystery

Not real clear.If mechanic didn't disconnect alarm and it was working you would be getting no oil alarm.Are you saying that the audible alarm horn doesn't work?Point being ,if the audible alarm is inoperable you may very well be getting a legitimate overtemp situation that is initiating the slow mode.Other possibilities are a malfuntioning temp sensor.If the VRO is in fact disconnected and you are mixing 50:1 ,simply unplug the four wire harness leading from VRO pump to the amphenol plug connector.Then you will need to trace the two wires from oil reservoir to engine compartment connectors and unplug them as well.This should leave the overtemp sensor and alarm circuit operable.

 

[clanton]

Re: 225 Evinrude Mystery

What are you using for a fuel pump?

 

[bradenton_whaler]

Re: 225 Evinrude Mystery

ob,<br /><br />I will look into the wires/ alarm. I bought the boat from a guy who told me that he had the mechanic disconnect the VRO. When I would place the key in/ turn the engine on, the beep would begin. I had my mechanic disconnect the alarm from the VRO.<br /><br />In terms of tempature... I have a water temp guage that began to work once I replaced the two thermostats. At idle, the engine is at 160 degrees and slightly drops once I move the boat. The water coming out of the engine is luke warm when running. I am not sure what else I can check to make sure that the engine is not overheating. As mentioned, I replaced the water pump in an effort to ensure that the engine is getting cooled. I really appreciate your input.

 

[bradenton_whaler]

Re: 225 Evinrude Mystery

Clanton,<br /><br />I am not sure I understan your question... I had my mechanic replace the VRO/ Fuel pump assembly when I first realized the problem. I initially thought that the engine was not getting enough fuel.

 

[ob]

Re: 225 Evinrude Mystery

bradenton_whaler,You need to locate the tan wire leading from temp sensor and with the key on groung it and see if the continuous alarm sounds.Depending upon the accuracy of the temp guage in boat 160 degrees is borderline.You can test temp with melt stik available through your dealer to touch check various locations of block and head covers when engine is up to temp.The melt stik recommended is 163 degree.

 

[bradenton_whaler]

Re: 225 Evinrude Mystery

Thanks. I will look for the tan wire at first light. Could a false indicator cause the engine to go into its "slow mode"? I really hope my problem is a simple electrical one.<br /><br />A general question if you have the time....<br /><br />Besides not having water flow, what else might cause an engine to overheat?<br /><br />Thanks.

 

[ob]

Re: 225 Evinrude Mystery

Faulty temp sensor could indeed cause symptom but is uncommon .If it is in fact overheating causes could range from cooling system components to lean cylinder condition.<br />It is important to insure that overtemp alarm is operable.Without it your flying blind.I believe on your motor tan wire from the port temp sensor is what you need to ground for test.

 

[clanton]

Re: 225 Evinrude Mystery

I ask about the pump, because some mechanics replace the VRO pump with an old style V6 fuel pump , which will not supply enough fuel. If the same mechanic did all of the work in your first post and you still have a problem look for different mechanic.

 

[clanton]

Re: 225 Evinrude Mystery

Repair alarm system.<br />Check magnets in flywheel.<br />Check upper crankshaft bearing housing bolts, when<br />Checking flywheel magnets.<br />Check blocking diode in tan wire in engine harness. Blocks false signal and signal from other sensors setting S.L.O.W.<br />Check shift switch.<br />Check fuel systen vacumn at full throttle, connect gauge at fuel restriction sensor connector, should be no more 4/5 inches vacumn.<br />Disconnect temp sensor tan wires to power pack, one one each head, run engine If rpms drop check power pack.

 

[clanton]

Re: 225 Evinrude Mystery

How close are you to I75?