91 evin.150s rebuilt, warning horn

[250Sportscraft]

Hello everyone,<br /> I just recently bought rebuilt 91 evinrudes 150s. The seller was awesome in following through on a few issues I had. I finally started the break in today. I got trough the first hour, the 1/2 throttle sequence no problems and i had to go high rpm to get on plane quickly. All was well. Then when I moved on to the 3/4 throttle phase, about 3 minutes into this part my warning horn chirped every 2 minutes or so maybe 3 times. Then it came on until I backed off to idle. This is the Starboard engine. The horn did not sound at idle but would go off at roughly 2000 rpm. Now the first issue I had after installing the motors a few weeks ago was the impeller. The seller promptly brought a friend/ mechanic. The impeller was fine but the shim had sheared and apparently was allowing the shaft to spin without turning the impeller. They replaced the shim and I had good water. At idle I still have great water pressure at the tell tale. However under speed I cannot see if the is a good stream due to the wake behind the boat. I'm thinking the shim sheared and at high rpm the impeller is not spinning faster? The VRO has been disconnected, I am running fuel 25:1 for the break in period. The fuel bulb was a little soft could it be fuel starvation causing the horn? I read that on one post. ANother post said something about high voltage. I am getting 14 + at lower rpms could the higher rpms be causing an electrical problem? hope this isn't to much, I'm just dying to get this boat straight again.

 

[ezeke]

Re: 91 evin.150s rebuilt, warning horn

I believe that once you correctly disconnect the VRO there is only the overheat warning which is a constant horn. There are more than two wires involved in removing the VRO. My motor is an '88, so you will need someone to confirm.

 

[250Sportscraft]

Re: 91 evin.150s rebuilt, warning horn

Ezeke, Thank you for taking time to provide some knowledge. I believe the VRO is disconnect properly. The person I bought the engines from did both engines the same. The port engine was completely rebuilt, the Starboard had key components replaced. I was looking through the manual at the section on vacuum testing the fuel system. It states an alarm may sound if the vacuum is too high. I think this is at the fuel filter on the carb. We made a hard turn and smelled gas about 5-10 minutes before this alarm began to sound. Like I said at first it was a little blurp every minute or two. Then it became a constant alarm at mid rpms , 2000 plus. New engines for me. Lucky for me the seller provided a service manual. I have a lot to read and learn. There are several issues that I see may be a problem. I just need a game plan. thanks again. <br />I just talked with the seller. He noticed that I have two different orafices at the tell tale. The little wafer on the engine that is not over heating has only one hole. The engine that is over heating has three or four holes.Could the lack of back pressure cause the water being pumped to NOT pull enough heat off the heads? Again the alarm does not go off till 2000 rpm.

 

[ezeke]

Re: 91 evin.150s rebuilt, warning horn

To the best of my knowledge there are only three signals at the control horn: <br />constant = overheat; <br />every half second = no oil; <br />every minute or so = low oil. <br /><br />On my VRO2 there are five wires to disconnect on each engine: 3 are in the three prong plug which you can trace off the pump; the other two are off the oil container and include the tan wire.

 

[250Sportscraft]

Re: 91 evin.150s rebuilt, warning horn

Well the initial horn was every minute. But it does idle and run up to 2000 rpm with out sounding the horn. The horn is constant until the engine is returned to idle.

 

[ezeke]

Re: 91 evin.150s rebuilt, warning horn

I think you need to see a wrench. The condition may be a bad water pump or some other simple problem, or it may be that the heat is because of the rebuild. <br /><br />In either case, it is unlikely that anyone can diagnose from here, we have never seen your motors.

 

[Seasport]

Re: 91 evin.150s rebuilt, warning horn

You need to verify if it's an overheating problem or not. Were the thermostats changed when the powerheads were rebuilt?

 

[Joe Reeves]

Re: 91 evin.150s rebuilt, warning horn

The V6 engines also have a vacuum switch which enables the same constant horn sound if a fuel restriction develops.<br /><br />Bottom line.... a constant horn warning sound can be either due to overheating or a fuel restriction. One has to figure out which.

 

[250Sportscraft]

Re: 91 evin.150s rebuilt, warning horn

OK the impeller is fine, and water is coming out the tell tale. No alarm. The thermostat is brand new. Again the motor ran for an hour at half throttle with no horn. Tomorrow I will put the boat in that water to get it up over 2000 rpm and see if the alarm sounds. I'm leaning towards fuel restriction

 

[Dhadley]

Re: 91 evin.150s rebuilt, warning horn

Its a fuel restriction if the horn is related directly to throttle position. If it was overheating it would still sound when you bring it back under 2000 until it cooled off. That takes some time. Do not run it until you figure it out. Pistons dont like to be starved for fuel. It could be anything from a plugged vent (if both motors run from the same tank its not likely) to a plugged anti-siphon valve to a crimped line to a plugged filter.<br /><br />Each engine feeds from a seperate line, right? From tank to filter to motor, each is seperate -- right? No fair running one line from the tank to a filter and then 2 lines from the filter.<br /><br />With the harness unplugged from the oil pump you wont get the Low Oil or No Oil warnings. At this point the only horn you have is for overheating and fuel pressure.

 

[250Sportscraft]

Re: 91 evin.150s rebuilt, warning horn

Thanks D, I have been waiting to hear from you. Yes there are two separate lines for each engine. My boat has been on the hill for a while. I siphoned the old gas out. I was starting to run low in the tank when this began, so i'm going to run outside right now and take the filter off. The VRO is disconnected properly. The filter screen on the engine was clean, so I'll work backwards. Thanks again.

 

[250Sportscraft]

Re: 91 evin.150s rebuilt, warning horn

Well, I finally had time to check out the fuel line. The vro filter at the carb was perfectly clean. The line between the filter and engine was clean. Then my filter. It had a good amount of rust sediment in. So of course a filter replacement is in order. And I'll buy a few extra. Is a single filter for each line the best answer? Or since I obviously have rust in the tank, should I put a set of the glass screens between the tank and the filter for the bigger stuff and let the filter do the water and small contaminant filtering? Do I also need to look at the fuel sending unit in the tank? Thanks for any information on fuel tank issues in advance.