I have a 93 mercury 150 xri (black max). When I am at low speeds, (gettin out of the hole) the temp gauge goes way up, and a couple of times my idiot light/ siren have gone off. This happens when I am at this low speed for a extended period of time, (2-3 minutes). A better example would be when I am idling kinda fast watching my graph for structure.
Now here's the kicker. The motor is spitting water good at idle, and at low and high speeds. If I get on the throttle and get out of the hole right away the temp is about where it should be. It is also fine when I am on plane cruising around. The temp is also good when I am idling and not in gear.
Any help trouble shooting would be appreciated. I am gonna try and replace the thermostat and see what happens.
Thanks in advance
Pat
Do you have a water pressure guage?
What does it show during the plowing times where the temp spikes?
Has it been a while since you had a new impeller put in?
Sounds a little weird, but they always say 'city' driving is harder on the engine than 'highway' driving...
I ended up speaking with 3 different marinas, and all three said that it was probably the impeller. So, I took it into Jans today, and they said I would probably have it tomorrow. I thought about doing it myself, but having never taken a lower unit apart I would hate to mess something up, so I figured I better let the pros take care of it.
Pat
I agree with your thoughts on messing with lower units - I don't have a great history with that.
I was thinking impeller too. I will cross my fingers for you that Jans does the job quickly and that you no longer have the problem.
I gotta give a good plug to Jan's Sports and Marine in Goodrich. I took my boat in on Tue around 430pm and I got a call around 1030am on Wed saying that they had the work completed on the boat. Now that is a pretty good turn around if you ask me. I am looking at being back on the water real soon thanks to Jan's
Pat
By the way the problem was the impeller and housing.
Pat
Glad it was diagnosed and fixed. Gotta have the boat working for a while yet... the good fishing is just getting ready to start.