B115tlrw 1998

[joefshmn]

This is the " Inshore" model.
It has the short shaft lower unit with the water pickup in line with the prop at the front of the nose cone.
Lately after I run on plane for about 10 -15 min the rpm inhibitor kicks in and i receive a high temp flashing indicator.
I drop into neutral and in less than 45 seconds the flasher goes out and i can run again sometimes for the rest of the day sometimes for another 10 -15 min.
I have recently replaced water pump and both thermostats.
Accept for this and some annoyingly long cold starts the motor is in excellent condition.
Any ideas where i should look next would be helpful.

[robert graham]

Maybe some sand or deposits in the water intake?....

[guitarzan413]

Sounds like a low water pick-up on your lower unit. They have smaller area to pick up water and any grass/trash can cause a quick overheat condition. Try putting in reverse to see if it expels any debris and turns off alarm. We have a lot of issues with those down here on gulf when running super shallow they pick up sand/shell/grass pretty easily. Good luck.

[zenoahphobic]

Sounds like a low water pick-up on your lower unit. They have smaller area to pick up water and any grass/trash can cause a quick overheat condition. Try putting in reverse to see if it expels any debris and turns off alarm. We have a lot of issues with those down here on gulf when running super shallow they pick up sand/shell/grass pretty easily. Good luck.

It would be nice if reverse gear also made the pump reverse it's flow.
Try hose on outlet or flushing connection if it has got one.

[TownsendsFJR1300]

Do you run in brackish or salt water?

How long have you had the engine (is it newish to you?)

AND, if used in salt water, brackish water, do you REGULARLY FLUSH the engine after every use?

If not flushed, with salt water use, the salt starts to collect in the water passages and harden up clogging up water flow to the head, water jackets.(triggering overheating)..


Here's some interesting threads that may help;

http://www.yamahaoutboardparts.com/f...g-th19434.html

http://www.yamahaoutboardparts.com/f...m-th23666.html

[rodbolt17]

are you POSITIVE its a temp lamp?

very few OEM tachs had temp indicates. usually they were in the speedo.

the indicates in most two stroke tach are oil.

[99yam40]

Rod how high is the water over there?
I hope you and your daughter's houses make it through this one OK

[rodbolt17]

99
no worries, no flooding this time. soaked but all is good in da hood.

[joefshmn]

Yep....small thermometer icon on the tach lens with a black bar on the LCD above it that flashes when overheated.

[rodbolt17]

the tach icon never had a black bar for temp.
your tach should have 3 squares with bars arrows or colors acrossed the bottom. the far left one is engine oil tank low,the center is remote tank low, the far right is remote tank ok.
the few tachs that used the temp icon it was above the left oil indicate and simply illuminated.

[rodbolt17]

also test the audible, you should be getting a tone with the visual.

[boscoe99]

Do we know what tachometer the OP has installed?

A -80 and later tachometer has a temperature icon with a bar over it that flashes when the motor over temps.

[rodbolt17]

dang I forgot about the -80. wasn't around but a few years.
still should have an audible if it flashes.

[joefshmn]

the tach icon never had a black bar for temp.
your tach should have 3 squares with bars arrows or colors acrossed the bottom. the far left one is engine oil tank low,the center is remote tank low, the far right is remote tank ok.
the few tachs that used the temp icon it was above the left oil indicate and simply illuminated.

Never say never......

[joefshmn]

I'm going to do the Rydlyme flush. Thanks to Scott for the threads.
I also went ahead and ordered a new thermoswitch.
Ill do the temp/continuity test on the old one when i find time but for now a $30 part is an easy way to eliminate a variable.
If i still have a problem after this I'm really in trouble as the entire cooling system will have been replaced.