1993 overheat buzzer

[dave chapman]

1st thing i noticed was engine computer would force engine into a missing mode and drop rpms too about 2000

about 3 min later able too resume normal operation for about 3 too 5 min then it happened again

took it too a mechanic.....disconnected....heat sensor on back left head...ran great....then plugged heat sensor back in and got the buzzer....by the way the buzzer never did work and now it works after the previous steps,,

maybe i reset the computer,,,,because it does not force the motor into the lowere rpm range,,,,,or is the buzzer the first indication...if ignored the computer will force the rpm reduction.....

i do not want too wreck the motor,,,,,any suggestions out there

dave

 

[rodbolt]

Re: 1993 overheat buzzer

never ever run it with the alarm system disabled.
try also posting the full model number so we know what we are disscussing and please find a real technician.

 

[P 0 P E Y E]

Re: 1993 overheat buzzer

Usually the overheat sensor is simply a normally open switch, that closes at overheat temp.

When the engine overheats, the switch closes and grounds out the P-Lead of the ignition and provides a ground for the buzzer to sound.

You could check the switch to see if it is always grounded, if it is you may be able to replace the switch.

Some engines have a limp mode when they run low on oil in the oil tank (2-strokes) But most do not have a limp mode for over temp,

 

[triumphrick]

Re: 1993 overheat buzzer

Many Yamaha motors have a limp mode on overheat. My 90 Yamaha had a blocked water passage and at higher rpm's would sound the buzzer and go into limp mode. The head was pulled and the passages were relieved,the motor was saved all because the alarm worked as it should.

 

[dave chapman]

Re: 1993 overheat buzzer

Thanks For The Replys

1993 Over Heat Buzzer
Yamaha 150 Pro V
Model P150tlrr6j9
Serial # 354535

 

[dave chapman]

Re: 1993 overheat buzzer

I HAVE ORDERED A NEW OVERHEAT SENSOR FOR THE BACK LEFT HEAD


LEFT SIDE MEANING THE STARBOARD SIDE OF THE BOAT

WHEN I PUT MY HAND ON THE HEADS I CAN KEEP MY HAND ON THE PORT BUT IT ONLY TAKES A SECOND TOO GET MY HANDS OFF THE STARBOARD SIDE

DAVE,,,,,,,dchap9@sympatico.ca

 

[dave chapman]

Re: 1993 overheat buzzer

i am also changing both thermostats.......will advise you all with what the outcome is..........

 

[dave chapman]

Re: 1993 overheat buzzer

when the thermostats were pulled the both had chunks of rubber in them

boat was bought second hand the impeller in the engine is good but i am assuming that it was previously replaced..

does the motor require a teardown too make sure the water jackets are clear or can it be flushed

the motor runs the same after replacing overheat sensor and thermostats

dave

 

[blandes]

Re: 1993 overheat buzzer

My Yammy 115 buzzer is going off when I rum more than 5 mins at 4,000 rpms or more. Any ideas out there? Water pressure is at 17.

Thanks

BL

 

[dave chapman]

Re: 1993 overheat buzzer

After Finding Chunks Of Rubber In The Thermostates And Retrying Engine We Tore Engine Down,,,,,,,,,,,,water Jackets Were Jammed Full Of Old Impeller Rubber...


Should Have It Back Together By Thursday And Will Report Back..


My Only Suggestion Too An Overheat Buzzer Going Off...is Pull Your Thermastats And See If You Too Have Bits And Pieces Of Crap Obstructing Proper Operation Of Your T Stats

Dave

 

[dave chapman]

Re: 1993 overheat buzzer

Motor Runs Great Now,,,,,,,,,yes All Because Yhe Dam Impeller.ate Itself And Plugged The Water Jackets.........might Be A Smart Thing Too Change Your Impeller Every 10 Years Dave

 

[Scrapiron]

Re: 1993 overheat buzzer

LOL I just bought a boat and im having the same issue....left head was getting hot, pulled it a few days ago and found rubber pieces as well....thermos however were clear. And although i found around 10 small pieces of rubber in the jackets, they seemed relatively small in the jackets, and im not sure that was the problem I ran a water hose though several diff place and i hope they are all clear, but im afraid there might be some blockage in some of the really small passageways. Anyhow, new impeller, thermos, PCV, and cleaned all the water jackets i could get to. Hope it works. Last of my parts should be here by next Wednesday. Anything else i can check that might cause overheating on one side between now and then?

thanks,
Scrap

 

[dave chapman]

Re: 1993 overheat buzzer

after pulling the heads too get rubber out of water jackest we pulled the main power head........it was clean good luck