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paul.lipsit's picture
Last seen: 3 months 5 days ago
Joined: 9/21/11
Posts: 16
Universal M25 engine temp alarm retrofit kit

I want to add an engine temperature alarm to my 1985 MK1 M25. Catalina Direct sells a suitable kit however, a sailor friend of mine, who is also a diesel mechanic says it's better to put a sender somewhere in the block. Having the sender on the thermostat housing won't alarm if the thermostat sticks closed. Makes sense but I took a look and can't find a place on the block to install one.

Paul Lipsit,
Zatarra #406
1985 C36 Mk1 S/R F/K
M-25 Universal Kubota
Port Dover, Ontario

Paul Lipsit,
Zatarra #406
1985 C36 Mk1 S/R F/K
M-25 Universal Kubota
Port Dover, Ontario
Catboat Willy
Last seen: 2 hours 14 min ago
Joined: 12/22/14
Posts: 200

 I wanted the same thing only I thought the first point of overheating 'sensing' should be the output water temperature itself, rather then waiting for the block to heat up and then sound an alarm. 
 We installed a Borel Water Alarm; 
Simple to install, test  and use. It uses a thermocouple on the engine water output and sounds an alarm when the water temp goes over 200 F.

Bill Dolan 1990 Catalina C-36 MKI - Hull #1041  'Williwaw'
Std. Rig, Walk Through, Wing Keel
M35, Oberdorfer Conversion,
Home Waters; SW Florida
'You are never out of work if you own a boat'

LeslieTroyer's picture
Last seen: 1 day 10 hours ago
Joined: 3/13/16
Posts: 419
I also installed the Borel overtemp alarm, but I do monitor the engine water temp with a Noland Engineering RS11 ( similar products from Actisence and others). Alarms show up on my MFD’s If you put a 1/8 hole in your T-stat bleading will be much easier and you’ll get hot water to the top of the cover where the sensor is. It won’t pass enough water to prevent the engine from getting to operating temp Les
Les & Trish Troyer
Everett, WA
1983 C-36 Hull #0094
C-36 MK 1 Technical Editor. 
Chachere's picture
Last seen: 10 hours 48 min ago
Joined: 10/27/10
Posts: 547

If the alarm's sensor is in the thermostat housing it (obviously) will be monitoring the fresh water loop at the same point as the temp gauge, and I'm not sure there is anything wrong with this.   Its purpose -- as I understand it -- is to overcome the reality that many of us are not eyeballing the temp gauge all that often (particularly on older C36s where the engine panel is located low on the aft end of the port seat). 

But then I'm one of those folks for whom the term "idiot lights" was appropriately devised -- I've been known to overlook (more times than I care to admit) the fuel gauge on my car's dashboard, smack in front of me. 

We installed the Catalina Direct kit maybe five years ago or so, and are glad we did.  I can assure you it definitely reacts quite quickly if you've gotten an overheating problem.


Matthew Chachère
s/v ¡Que Chévere! #466
1985 C36 MKI tall rig fin keel M25
Homeported in eastern Long Island, NY

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