Old Salts, "New" '82 30': 5411 sensors

Mar 10, 2015
62
Catalina 30 Moss Landing, CA
By way of intro, I (75) and Louise (74) have been boatless for 9 years since we moved west, discounting our little Hobie Tandem Island sail/pedal kayak that's ill-suited to Monterey Bay's always cold/frequently very windy waters. Since retiring in '94, we've sailed about 24,000 nm's in three boats -a 28' cat-ketch trailed from FL to Pac. NW and Sea of Cortez; Gemini 34 cat. to Bahamas' near and far out-islands; and a Fountain-Pajot 37' cat from British Columbia, down the coast for 2 years in Mexico/Central America, through the Canal and up to top of Nova Scotia, and back to St. Andrew Bay in NW FL. in '00. Sold the cat, and restored a fairly beat-up, now lovely Herreshoff Meadowlark 37 leeboard ketch which I was very sad to part with..

Our three "Kids" (47-53) thought we were nuts when we bought an old, tired Cat. 30 on Valentine's Day to celebrate our 53rd Anniversary and my birthday. It had a hard life the past seven years, going out under power only a few times from Moss Landing (between Monterey and Santa Cruz), and an episode flooding over the floorboards. Judging by the five bags of well-used laminate headsails & spinn., it had been raced hard on SF Bay by a previous owner.

But the little MD5411 ran well and could push her a little over 6 knots at full throttle (2750 RPM) after bottom/prop scrub. But the temp never rose on the newish engine inst. panel. I replaced the totally corroded thermostat, to no effect on the gauge, which led me to look for the temp. sensor - not to be found with light and mirrors, nor anything resembling an oil pressure sender (panel light only, which should have, but didn't light with key on before starting. There were a couple of screwed in gray elements without terminals I took to be zincs - which the engine shouldn't have, being RWC??

No luck searching the web for location of these sensors, and the parts catalog with the boat was illegible due to water soaking in nav.desk. These are among the last problems to get a handle on.

Samantha
sails beautifully with her little furling lapper (by Pineapple Sails, no less!) and a little used Doyle Stackpak main with a great shape. The cockpit is roomy with the pedestal steering, and proteced with a well-crafted dodger, with even a zip-on Bimini w/ side curtains. The interior layout is great and very inviting with its newish cushions, new stove/oven, refridge., and even flatscreen TV!

Thanks for any help!
Pete
 

jrowan

.
Mar 5, 2011
1,294
O'Day 35 Severn River, Mobjack Bay, Va.
Sounds like you got a nice boat if someone put a Doyle stack pack on her. I also have the venerable, but much berated 5411 engine. They are very tough, & rarely ever reach over 185 degrees. I believe the temp. sending wire runs from the gauge back to the engine & the sensor is near the thermostat housing. Just follow the wire back to the engine & you will find it. I wouldn't worry about the motor overheating, as it always runs on the cool side, as its raw water cooled. You are likely also aware that when the thermo. loop is closed it will not discharge any raw water at the transom until the thermo opens up at running temp.
 
Mar 10, 2015
62
Catalina 30 Moss Landing, CA
Sounds like you got a nice boat if someone put a Doyle stack pack on her. I also have the venerable, but much berated 5411 engine. They are very tough, & rarely ever reach over 185 degrees. I believe the temp. sending wire runs from the gauge back to the engine & the sensor is near the thermostat housing. Just follow the wire back to the engine & you will find it. I wouldn't worry about the motor overheating, as it always runs on the cool side, as its raw water cooled. You are likely also aware that when the thermo. loop is closed it will not discharge any raw water at the transom until the thermo opens up at running temp.
Thanks! Finally found the temp sensor high on engine front, partially concealed by a hose., with corroded contact, which I cleaned to bright copper. Oil sensor below the aft end of the starter and pretty inaccessible without starter removal.

There is a fairly brisk flow of exaust water from the get-go even with no thermal loop, and the only way water can pass the thermostat cold is through two small holes in t-stat mounting flange. The t-stat opens on hot water pan check well before boiling - otherwise closed, so I'm hoping adding the thermal loop will allow the engine to reach operating temp in the always cold Monterey Bay waters.

Pete
 

jrowan

.
Mar 5, 2011
1,294
O'Day 35 Severn River, Mobjack Bay, Va.
Post some pics of the exterior & interior. We sailors love seeing pics!