Yamaha 115 Alarm Sounding

[David G]

I have put in a new water pump, new thermostats, and a new popit valve, and the alarm still goes off when I run above 4500 RPM's for mor than a few minutes. I can ***** for hours and it never goes off. Oil tank is full. Many thanks.

[boats.net]

Was the water pump housing in good shape, not melted, the stainless cup not melted in housing?

[David G]

Yes, they all were in good shape. None were melted, I put in a new SS housing that came in the kit.

[boats.net]

The next step would be to remove cylinder heads and clean water jackets in head and around cylinder sleeves, passages may be plugged up with debris.

[captpn]

is it really overheating? sometimes a faulty temp sensors can go off too early, was steam coming out, was the tell tale hot? also, did you clean out where the popit valve was...a sticking poppet valve can cause this too..good to check before you pull the heads.

[Hamfisted]

Water Pressure gauge...

Also look at installing a Yamaha water pressure gauge if you don't have one already. This will always tell you if you've got good water pressure trying to to cool the motor, and your problem is elsewhere. How old is the motor? Did you use the new "mushroom head" designed poppit valve?




-Mike