Home › Forum › Ask A Member › Installing a telltale › Re: Installing a telltale
Seakaye12 we will start with your post first. The answer to your question is yes. OMC for years (later years anyway) had their telltale only show the water pump was pumping. It did not show you the powerhead was cooling. Some large engines had the hose coming off the powerhead adapter. It would be rare, but water could never even get to the powerhead.
Now back to the motor at hand. I may be wrong, but if the thermostat worked perfectly (they rarely seal perfectly) then you wouldn’t get any water out the overboard telltale while the thermostat is closed? If this engine has a bypass, then the motor will run cold because you have provided a short circuit around the thermostat? Correct me if I am wrong, but that is the way I see it. You have to be careful where you put in a telltale. If you let water out of the powerhead that is not controlled by the thermostat it is just as problematic as not having a thermostat in the first place.
Mercury does theirs differently on the V-6s, but I am not sure how they do the small motors. They have a poppet valve on big motors. That system does show you hot water after it has been through the powerhead. Both systems have positives & negatives to them.
Dan in TN