Before Posting, Please Read Our Posting Guidelines Below.
1. Use the full 4 digit year for everything you are asking your question about. Example: 1962, 1988, 2000, 2011 2. Include the correct name of your Whaler model. Example: Montauk 17, Montauk 170, Outrage 26, Outrage 260 3. Include the length when necessary. Example: 16, 17, 18, 20, 22 4. Do not post your email address anywhere on this site as it is already in your user profile.
Running the boat at WOT for about 15 minutes in the SF Bay.
Continuous Alarm indicating overheat.
Bring to idle.
30 seconds or so later alarm goes off.
Cannot go above 2500 rpm. (normal)
Pull cover off and measure head temps at 166 and 152 degrees.
Turn engine off and back on again.
No alarm, spend another hour or so tooling around and alarm goes off again.
Temps about the same as before: 157, 155.
Turn engine off, back on and no problem....
I have had the boat in twice to the shop. They have ran it over 1/2 hour each time but cannot repeat the problem. They do admit they cannot run it WOT, because they don't have a big enough tank.
I asked them to replace the thermostats and they did.
The problem still exists.
When the alarm sounds, I would start pulling one selected alarm wire at a time until the alarm goes off.
Start with the Oil Tank wire.
Then overheat alarm wire, etc....
You should be able to find which wire or system is sounding the alarm.
It could even be the alarm itself.
By any chance, is there a lot of slop in your ignition key assembly? There was on the key to my 95 115 when I had this or a very similar problem. I never figured out what it was definitively, though it wasn't a overheat. I noticed that the ignition key chamber was sloppy and loose, and wondered if, with the bulky key chain I had dangling from it, it was intermittently tripping the neutral safety switch as it swung around underway. Not 100% sure that's what it was, but I got rid of that key chain and haven't had the problem since.
Take the technician with you to do an "in the water test". We do it all the time. It sound like it's the only way you can duplicate the problem. It sounds to me like a water pump impeller going bad, maybe missing one of its fins, but it could be something else. I had this same problem once, changed the impeller and all was good. Bottom line, take the tech out and make it fail.
