15 hp merc

[nlar]

I bought a 1992 15 hp merc. Great running motor but obviously has a thermostat with the water stream coming and going under power and so on. Here is my question, if I take the thermostat out will I get a constant water flow (as I would like to see)? All of my other motors have a constant water flow coming out and it makes me nervous when it goes down to a trickle but then goes back to a solid flow, I find myself spending more time looking back at the water flow then I do at what's in front of the boat!

 

[will941s]

Re: 15 hp merc

Keep the thermostat replaced about every year and keep the water pump changed, and don't worry about it. I had the question about my merc 25 and as one person pointed out to me, the engine is designed to run at it's peak at a certain temp, and the the water is directed to the passages it needs to be by the back pressure from the stat. Without it, the cylinders won't run at the rec. temp and you will foul plugs alot more often, the engine will run too cool in places where it needs to be warmer, causing distortion in the internal parts, and you will lose fuel economy. Then to make it hit home, I saw a merc 15 throw a rod caused by effects of not running a t-stat. So, I say....if you got a new (used) motor, spend the money and service the cooling system, and have the peace of mind knowing the parts are new and go fishing.