Tell tail water never warms

[Lootas1]

Just bought a nice 1985 Honda BF100. Starts and runs great. Sends out a good stream of water but, even after five minutes of running in tank (both idle and some higher speeds) the water remains cold. Not at all warmer than when I start the motor and water temp is in the 40s F. A friend with a similar (but newer Honda) says that no need to worry about the thermostat not opening. The engine doesn't overheat. How can that be? Is he right? I'm no mechanic and it looks like replacing the thermostat is a rather major job.

 

[jrttoday]

it's OK to be concerned, but don't freak out..... yet!! lol An outboard is not an outboard and I have Johnson and Mariner two stroke outboards, but in theory much is the same. Get ahold of two temp sticks appropriate to your motor - high/low.

make marks on the head and the low should melt, and not the high. In a tank, my little 8hp Mariner never melts the low just idling on a cool day - and that's not saying anything about how your's should operate

 

[scout-j-m]

The temp of the water coming out of the tell tale isn't necessarily the best way to judge the engine operating temp. Water comes out of the tell tale no matter if the engine's thermostat is open or not. I don't have any experience with Hondas/Nissans/Tohatsus but on my Force the tell tale water never got real warm until it had been idling in the tub for a while. I equate this to the tub's water heating up due to the warmer water and exhaust being spit out through the prop hub and into the tank. Even idling in a warm summer lake, the tell tale water never got too much warmer than the actual lake water.

I say check your thermostat on the stove as it should be easy to remove and check. If it is good and it is spitting water I'd say you are good to go. Maybe if a friend has an IR laser thermometer you can borrow that and check the block and head temps after warming it up and then after a few WOT runs.

 

[Lootas1]

Know this isn't how a scientist would do it but I have maybe 35-40 gallons of water at around 45 degrees F in my 55 gallon drum. I start the Honda and run it five or more minutes and then put my hand in tell tale. Then lower my hand into the tank and the water temperature seems unchanged. I was told by a boating friend with a 1995 Honda (ten years newer than mine) that no need for concern about the cold water from the tell tale. That just goes against what I know about outboards (which, I guess, isn't all that much).

 

[Sea Rider]

If thermo is doing its work OK, should never get warm as this is just a water indicator that water pump is working ok with no obstructed water intakes at lower leg. Usually is not connected direct to the power head water circuit but rather along water path.

Happy Boating

 

[gm280]

You could buy a cheap LASER temperature gun/reader and check the actual engine . If there are any issues with the engine, then you have something to worry about. Otherwise, I don't see anything with cool water coming out the tell tail stream.

 

[isaksp00]

On my small Honda (8HP) the tell tale water is never warm. The water that routes to it may not ever go through any of the actual cooling circuits.