Another 1988 Yamaha 150 ProV150 Alarm HELP PLEASE!! ANY MASTERS OUT THERE?

[smorrow]

I know this topic has been covered because I have read them. I will try to explain what I have done and see if anyone else has suggestions.

My engine alarm goes off at idle after 5 minutes.
I have:
Tested the thermostats and they open and close at the appropriate temp.
Replaced the Poppit (Pressure Relief Valve)
Replaced the exhaust gaskets and cleaned out the manifolds.
Inspected the Water Pump (impeller) and it is only 10 months old and looks fine.
Tested both the primary and external oil tanks with an ohmmeter and they both worked.

Not sure what else to do. Any advice is appreciated.

 

[99yam40]

Re: Another 1988 Yamaha 150 ProV150 Alarm HELP PLEASE!! ANY MASTERS OUT THERE?

I thought you said the alarm clears if running it a low RPM after it comes in.
Do you have gauges that indicate what alarm is sounding?

 

[Capt Ken]

Re: Another 1988 Yamaha 150 ProV150 Alarm HELP PLEASE!! ANY MASTERS OUT THERE?

Use a infrared thermometer to see which head is overheating. If its the starboard side then you are not getting enough water pressure to reach the top probably. Another trick is to remove the thermostat cover and thermostat. Start the engine and see if water pumps out the hole.

 

[JB]

Re: Another 1988 Yamaha 150 ProV150 Alarm HELP PLEASE!! ANY MASTERS OUT THERE?

Please DO NOT YELL!!

http://forums.iboats.com/showthread.php?t=250876

 

[smorrow]

Re: Another 1988 Yamaha 150 ProV150 Alarm HELP PLEASE!! ANY MASTERS OUT THERE?

The gauge I have are the oil level indicators. Red, yellow and green. That's it.

 

[smorrow]

Re: Another 1988 Yamaha 150 ProV150 Alarm HELP PLEASE!! ANY MASTERS OUT THERE?

JB, it's a yell of frustration........

 

[Capt Ken]

Re: Another 1988 Yamaha 150 ProV150 Alarm HELP PLEASE!! ANY MASTERS OUT THERE?

Frustration from not understanding the system. If it only alarms at idle, then its a water pressure problem. So what determines water pressure? Water pump and poppet valve. So unless the poppet valve has some trash holding it open, then its the pump. I don't care what the impeller looks like being its only one part of the pump. Is all the gaskets and o rings in the pump housing sealing? Is the rubber seat that the water tube slides into in good shape? How about the stainless cup in the pump housing?

 

[smorrow]

Re: Another 1988 Yamaha 150 ProV150 Alarm HELP PLEASE!! ANY MASTERS OUT THERE?

Ken, I removed both thermostats. What is interesting is that the alarm did not go off while the thermostats were out. I did notice that the starboard (driver) side had less water flow then the port side. The temp seemed to be hotter from the starboard side as well. When I installed the thermostats and restarted it, the alarm came back on. I think at least we can say it is probably a temp alarm, right?
I took a quick video and posted it on YouTube to see. Thanks Ken for the suggestions.
http://www.youtube.com/watch?v=XkPKoPDTZ5I&feature=youtu.be

 

[smorrow]

Re: Another 1988 Yamaha 150 ProV150 Alarm HELP PLEASE!! ANY MASTERS OUT THERE?

Update:
I bought a thermometer and the starboard side is 191 degrees and the Port side is 150 at the time the alarm went off.....

 

[99yam40]

Re: Another 1988 Yamaha 150 ProV150 Alarm HELP PLEASE!! ANY MASTERS OUT THERE?

So now you know it is overheating for sure and not much water coming out the stat holes.

Did you replace the grommet and spring with the new Pressure relief valve you installed?
Grommet swelling due to corrosion behind it is what usually causes the sticking.

Replace water pump with a kit it contains cup, wear plate, impeller, gaskets,and orings.
Inspect pump housing to see if any signs of melting plastic and replace that also if needed

 

[JB]

Re: Another 1988 Yamaha 150 ProV150 Alarm HELP PLEASE!! ANY MASTERS OUT THERE?

JB, it's a yell of frustration........

Perhaps so, and I sympathize, but we didn't cause it and we need facts, not whines, to be able to help.

 

[smorrow]

Re: Another 1988 Yamaha 150 ProV150 Alarm HELP PLEASE!! ANY MASTERS OUT THERE?

I replaced all parts of the pressure relief valve including the outside cover. Grommet, Valve, Spring and Casing.
If you look at the YouTube video I posted above, you can see the water stream. Do you think it is sufficient or should I replace the impeller even though I have a nice stream?

 

[Ldavidgrover]

Re: Another 1988 Yamaha 150 ProV150 Alarm HELP PLEASE!! ANY MASTERS OUT THERE?

JB your out of control. Anyway Pull the heads and clean the scale/ salt and water jackets. It's a maintance kind of thing

 

[smorrow]

Re: Another 1988 Yamaha 150 ProV150 Alarm HELP PLEASE!! ANY MASTERS OUT THERE?

Update:
I changed the impeller. Alarm still sounds.

I am not sure if anyone saw the youtube video I posted...but I am not sure why water comes out of one thermostat hole much more than the other.

Anyway, I am about to give up. Not sure if there is anything else to do.

 

[99yam40]

Re: Another 1988 Yamaha 150 ProV150 Alarm HELP PLEASE!! ANY MASTERS OUT THERE?

So you refuse to replace the rest of the pump parts to see if that helps?

 

[smorrow]

Re: Another 1988 Yamaha 150 ProV150 Alarm HELP PLEASE!! ANY MASTERS OUT THERE?

Actually I did change the whole thing. The kit had the housing, impeller, gaskets, two o rings, etc.... I changed it all out just to be safe.
The guy at the parts store thought it may be a plugged engine since the water comes out stronger on one side through the thermostat holes....