was wondering whats the difficulty of changing a thermostat on a 1981 140hp evinrude?thanks

a 1 very easy

how much do these usually cost,also is there a way to test this cause my overheating alarm still goes off every now and then after i got a new waterpump put in

They are around 20.00. Take them out and look at them. If they are rusted or have corrosion on them they could be bad. Put them in hot / boiling water and see if they open up. If not or not all the way it could be your problem.

Thermostats could be the cause, but I will almost bet the farm, the water diverter tubes are causing the problem.....

where exactly is the thermostat on my motor?

Research it here Iboats . If yours is like my 115 they are located at the back of the motor under the heads. It is not the easiest thing to change but, not impossible. In my case the trick had to do with rubber banding all of the pieces together to keep the assembly right until I could slide it in place. Then remove (cut) rubber bands and pull them out. It also helps to have a 1/4 drive socket set with deep sockets and some offest wrenches. I may have some links somewhere to tips but, you can probaly find all the help you need on the Iboats repair forum.

I bought mine here marineengine.com