'91 20 hp evinrude possible bad thermostat/heat sensor?

[67Mirro]

I'm revisiting this forum again from a couple years back as my problem still persist. I have attached a video for reference. Boat motor seems to this when I'm just putting out of channel and it gets hot or if I've been running it then slow down to idle then try to get up on plane again. I've noticed when it does this the water is very hot from tell tale, so if i increase throttle just enough before it starts kicking the rpms down and putt for a few minutes the water gets cooler from tell tale and then i can accelerate to full throttle with no problem, as if its cooled down enoigh or fooled the sensor? maybe a bad thermostat or sensor? any thoughts? (new wp installed)
View attachment Video.mov

 

[racerone]

A classic case of lean sneeze.----Adjust carburetor slow speed mix.----Throttle plate is opening too soon is a possibility.-----Put

 

[flyingscott]

that seems like a fuel problem. What happens when you pump the primer ball?

 

[racerone]

Put motor in lowest idle.----Post picture of the adjustable stop on the rod that goes forward to the carburetor.----Many folks are confused on how that is set / adjusted.

 

[67Mirro]

Put motor in lowest idle.----Post picture of the adjustable stop on the rod that goes forward to the carburetor.----Many folks are confused on how that is set / adjusted.

ok, i havnt adjusted one of these ever before so find the lean screw on the carb then?

 

[racerone]

Slow speed mixture screw.----And the adjustment on that rod.----So 2 things to look at and adjust I think.

 

[67Mirro]

Slow speed mixture screw.----And the adjustment on that rod.----So 2 things to look at and adjust I think.

so i want to tighten up the adjustment rod?

 

[67Mirro]

also i cant get out of this mode for 5-10 minutes it wont let me get going at all i have to keep trying for 5-10 minutes. that's why i thought electrical sensor because it wont let me get out of it.

 

[racerone]

You need to adjust the stop on that rod.----It is an adjustment that looks wrong to folks when in fact it is correct.

 

[ct1762@gmail.com]

but the other issues seems to be overheating. remove the thermostat cover. clean t stat seat in block. install new head cover gasket and greased up t stat.

 

[67Mirro]

but the other issues seems to be overheating. remove the thermostat cover. clean t stat seat in block. install new head cover gasket and greased up t stat.

Yea I bought a new tstat And gasket going to take it with me when I go to this weekend and hopefully that fixes it. Im thinking it’s stuck closed, so when I idle a bit above resting it cools it enough to get going

 

[67Mirro]

Was just on the water again, it did it again so I unplugged the temp sensor and it ran as normal(I only revd it up and wasn’t bucking ) then plugged back in again and started bucking. Believe the temp sensor is doing it’s job and the thermostat is stuck closed.

 

[ct1762@gmail.com]

Was just on the water again, it did it again so I unplugged the temp sensor and it ran as normal(I only revd it up and wasn’t bucking ) then plugged back in again and started bucking. Believe the temp sensor is doing it’s job and the thermostat is stuck closed.

do NOT run it any more until overheating issue has been sorted. temp senders rarely go bad. i think ive only seen 2 or 3 in 15 years

 

[67Mirro]

do NOT run it any more until overheating issue has been sorted. temp senders rarely go bad. i think ive only seen 2 or 3 in 15 years

Yes we got it sorted with tstat we believe