merc 150 black max cooling and idle

[mwhatch]

I just bought a boat with a 1986 150 black max with oil injection. When I run the motor with ear muffs, it takes about 30 seconds before the water comes out of the tell-tale hole. When on the lake, i may be a bit sooner. Also, it idles around 1000 rpm. I get 60mph at 5500 rpm, so it seems to be running good. I am new with these bigger motors and was just wondering if everything was OK. Thanks.

 

[WillyBWright]

Re: merc 150 black max cooling and idle

The (insert adjective here) Mercury engineers designed it so that it only pees when one or more thermostats open up. That takes at least half a minute. If a water pump is destroying itself from lack of water, it takes about half a minute. So I have plenty of adjectives for Mercury engineers, none of which I'm sure they'd like to hear.

In the water and in gear, it should idle 650-750 RPMs. On the muffs, it might idle around 1K.