Yamaha 40hp 2 cycle Alarm signal

sherpaq · #1 July 18th, 2005, 01:44 PM

I have a 1999 yamaha outboard that goes for about 5 minutes and the alarm goes off. I wait 15 seconds idling and can go again.

No obstruction visible to show overheating-- although I do see steam around motor when stopping-- assume this is normal from running.

This has oil injection-- and I see a small air gap about 1 inch in the line. Could this be preventing flow of oil to system and causing it to shut down? The oil level is where it should be.

Should I simply try to add some oil to line to remove the air gap?

Any other suggestions?

Thanks,

ET

Details on motor:

Yamaha 6h4 40 ELRY L8439T5

40 hp 2 stroke motor with Oil injection--

sherpaq · #2 July 18th, 2005, 09:28 PM

I checked the air gap in the oil line and it was not in the line feeding the motor but along the side where the oil is fed back into the receptacle.

This means something else is going on. I took off the small plastic cover over the water intake and it was only slightly clogged along one edge--one of the slits was covered.

Is it possible one of the sensors is not reading correctly?

thanks for your help!

31900 · #3 July 18th, 2005, 11:44 PM

Tell us more. The steam doesn't happen where I live but it is warmer here. How is the telltale? When was the water pump serviced?

sherpaq · #4 July 19th, 2005, 08:11 PM

I am in the puget sound with the boat. Cold water. I am getting water exiting the cooling system with no blockage. Do the sensors ever go bad on these?

I don't know anything about the water pump service. Do these need servicing every so many hours and how is this done?

Any other things I can check. Motor starts great and runs great until the alarm goes off. First trips I had no such problems.

Thanks,

ET

Lasse Lehtonen · #5 July 20th, 2005, 01:08 AM

Is it a long continuous "beeeeeeeeeeep" or "beep beep beep...", the continuous beep means its overheating and that beep beep beep means there is an oil injection problem. Waterpump impeller is good to change every two years or if you use it very much, every year.If the motor has been sitting for a long time the waterpump impeller needs also to be replaced. The steam coming from the upper exhaust you told us about is normal when running in cold water/ or air temp is low. Sensors can go bad but before replacing any sensors check that there is no any real problem.

sherpaq · #6 July 20th, 2005, 09:57 AM

Thanks much for this info. I have a long beep sound so it must relate to the cooling. Is the waterpump impeller a pain to replace? I wish I had a temperature reading from the motor to more accurately see if the temp is really going high.

Thanks,

ET

Lasse Lehtonen · #7 July 20th, 2005, 11:15 AM

Is there a good stream of water coming from the "pee hole", if there is a good stream the problem may be in the thermostats or in the valve that controls the cooling water flow inside your motor. At higher speeds the valve (there is a spring in the valve wich should let it open when water pressure increases) should open, if it does not there is not enough cooling water flowing through. I will try to figure out where is that valve situated and Ill post here when I know.