Diesel Engine

The Catalina 34 has had at least three different motors. The

• M-25, a 3-cyl, 21 hp engine, was installed on the the early models.
• M-25XP (3-cyl, 23 hp) became standard in 1988.
• M-30, a 4-cylinder producing 28hp, became an optional engine about the same time and is standard in the Mark II.

All are produced under the Universal Motors brand (now Westerbeke Corporation). Due to lack of available supplies, the factory occasionally installed a Yanmar engine (note: Yanmars are higher-compression engines, which do not require glow plugs).

General

CRITICAL UPGRADES includes a lot of engine information: Critical Upgrades http://c34.org/bbs/index.php/topic,5078.0.html

RESOURCES - good M25 engine information,from a C36 owner

Spares for a Long Cruise

http://c34.org/bbs/index.php/topic,4590.0.html

Bleeding 101 http://c34.org/bbs/index.php/topic,6377.0.html

Cooling

• Heat exchanger maintenance, including zinc change
  
• Heat exchanger upgrade to 3" version to prevent overheating
  
• Overheating as a result of an air lock
  
• Raw water pump, impellers and cooling system (Ron Hill's May 2002 Mainsheet article on Rebuilding an Oberdorfer water pump)
• Raw water pump: Loss of self-priming capability
  
• Water heater doesn't heat when motoring
  
• 3" heat exchanger mounts
• Water Pump Impellers
• Heat Exchanger Pictures
• Replacing a Sherwood Water Pump with an Oberdorfer
• Rebuilding an OBERDORFER Raw Water Pump with Flix includes MODEL numbers for the Oberdorfer replacement pumps, see reply #12: http://c34.org/bbs/index.php/topic,6766.0.html
• HEAT EXCHANGER SOURCES and Replacement Bracket and Exchanger with Pictures http://c34.org/bbs/index.php/topic,6920.0.html
• COOLANT PUMP PARTS RESOURCE http://forums.catalina.sailboatowners.com/showthread.php?t=169680

• FRESHWATER COOLANT PUMP Parts # and Sources http://c34.org/bbs/index.php/topic,8939.0.html

• Rebuilding an Exhaust Riser (also from Dave and a C36 skipper [previously posted]) http://www.realitycheck.me/building-...aust-riser.htm

• Why do some of our engines have different Oberdorfer sea water pumps than others, and what about that cir-clip "holding on the impeller"?

The first part pertains more to C30's with M-25s/Oberdorfer pumps, than to M-25XPs -- but it's interesting background anyway.... 
The second part pertains to all those with Ob pumps, and is subtitled "Yes, you're right ...but we don't tell customers that."
--KWKloeber 15 May 2015

• Why SHERWOOD Raw Water Pumps leave a LOT to be desired: See reply #7 here: http://c34.org/bbs/index.php/topic,8493.0.html

Thanks to Ken for that one, I'm tired of repeating it. - Stu  5/25/2015

• Engine Thermostats

 M-25/XP/XPA; 35/A; early M-25XPB (to March 1998) use these 38mm diameter thermostats:
 160* F - Universal p/n 301358 or Kubota p/n 1E399-73010 (replaces 19203-73014, 19203-73013, 19203-73010.)
 180* F - Kubota p/n 15531-73014 (replaces 15531-73013, 15531-73011.)
 38mm Gasket - Universal p/n or Kubota p/n 16851-73270 (replaces 15676-73270, 15531-73270, 15676-73272.)
 
 Later M25-XPBs (after March 1998) 44mm 160* F thermostat
 Universal p/n 201001 or Kubota p/n 19434-73014 (replaces 19434-73010, 19434-73013)
 44mm Gasket - Universal p/n 298843 or Kubota p/n ?
 
 See Service Bulletin #107, Kubota Tstats likely won’t have a bypass hole, so drill a 1/8” hole, or two, thru the inside edge 
 of its flange so there is a constant coolant flow thru the exhaust manifold when the Tstat is closed.

Electrical

• Alternator mount/bracket upgrade Important safety upgrade for M25 (not XP) owners by Stu Jackson
  
• Engine harness upgrade: A comprehensive overview by Gerry Douglas Important WARNING for M25 owners
  
• Engine Harness Upgrade from Maine Sail http://www.pbase.com/mainecruising/universal_wiring_harness_upgrade and http://forums.catalina.sailboatowners.com/showthread.php?t=135558
• Engine harness upgrade by Capt. Al
  Important FIRE HAZARD for M25 series owners
  
• Glow Plug Solenoid or Relay Installation for faster starting
  
• Secondary start switch
  
• Slow start fix with a wiring upgrade, starter re-build, and new starting battery by Mike Vaccaro
  
• Tachometer Malfunction Q&A
  
• Cockpit Engine Panel Gauge Troubleshooting Steps --K Kloeber 11/3/2014

Thermostat Sender Source http://c34.org/bbs/index.php/topic,7985.0.html]]

Engine cockpit panel wiring diagram from CD.com, thanks to Noah http://www.catalinadirect.com/index.cfm/feature/73/z2644--z2855-instrument-panel-wiring-diagram.cfm

Exhaust System

The hot exhaust gases are mixed with cooling water in the exhaust elbow and water muffler on their way to the exhaust outlet in the stern of the boat.

• Exhaust pipe replacement
  
• Hump hose replacement guidance
  
• Exhaust Hose Replacement with Pictures EXCELLENT 4 page discussion with Flix on pages 3 & 4 by Stu http://c34.org/bbs/index.php/topic,6760.0.html
• EXHAUST NIPPLE from Westerbeke (courtesy of Dave Mauney, O'Day 35, 1989, "DAMWEGAS" , Oriental, NC , M25XP) http://www.westerbeke.com/SinglePart...f73b1ca82d9219 That link no longer works. Try this: http://www.westerbeke.com/search/Asc/10-0/exhaust%20nipple I got it under parts, search for exhaust nipple.
• Rebuilding an Exhaust Riser (also from Dave and a C36 skipper [previously posted]) http://www.realitycheck.me/building-...aust-riser.htm
• Water-lift muffler: Repair or replace?
  
• Repairing an AquaLift muffler (with pictures) From C-30 owner Mark Hamilton
  
• C34 Exhaust with Water Cooled Riser From C-34 owner Bill Shreeves
  

Fuel

• Fuel issues and advice (takes you to another section)
  

Mechanical

• Adjusting Valves
• All about alternator belt tension & pulleys
  
• Air Filters (Be the first to contribute your experience here!)
  
• Blow by (Be the first to contribute your experience here!)
  
• Changing engine mounts
  
• Engine mount protector
  
• Oil change hose replacement project
  
• Oil pan replacement project to fix leaking oil Pan
  
• Rebuilding a M25xp by Dave Sanner
  
• Replacement filters, belts, and oils equivalents list: find alternate replacement brands
  

• Kubota Filter Equivalents http://www.orangetractortalks.com/2008/12/gray-market-kubota-oil-filter-part-numbers/
  

[NOTE] The filter interchanges at the above OTT website can't necessarily be trusted; double-check if you use them.
For instance, OTT lists NAPA p/n 3389 for both fuel and lube application. I brought this to OTT's attention and suggested they correct its list. OTT asked ME to provide THEM all the correct interchange numbers and they would revise the website.
I don't THINK so. :-) --KWKloeber 21:33, 29 June 2014 (PDT)

• Universal M-25 & M25XP Alternator Bracket Upgrade & Alignment IMPORTANT http://c34.org/bbs/index.php/topic,7917.0.html
• Universal Diesel Owner's, Parts, and Service Manuals

Transmission

• Solving engine power loss: Working on the injection pump
  
• Transmissions: Checking the oil
  
• Transmission Fluid 101 - link to the message board: http://c34.org/bbs/index.php/topic,6417.0.html
• Better Transmission Dipstick Access - by Phil Spicer = link to the message board: http://c34.org/bbs/index.php/topic,8828.0.html
• Transmissions: The right gear while under sail
  
• Transmission Drain Plug Replacement for Crush Washer - thanks to Loren Beach http://www.ericsonyachts.org/infoexchange/entry.php?213-Hurth-17-mm-Drain-Plug-washer
• Hurth Detailed Searchable Parts Manual - KKloeber 2016-5-13

Misc Projects

• Engine compartment cover hinge
  
• Removing Engine Using Boom
• KUBOTA equivalent parts http://c34.org/bbs/index.php/topic,978.0.html

• Removing Engine Catalina 30 from Captain Dan with photos - good ideas for re-bracing engine mounts, too http://forums.catalina.sailboatowners.com/showthread.php?t=168891

• Options to Route Crankcase Breather Hose to Air Intake VIEW THE PDF - K KLoeber May 2015

• Remote Oil Filter Details from Maine Sail: http://www.sailnet.com/forums/engines/230865-remote-oil-filter-kubota-diesel.html#post3224841

Shaft & Propeller

• Flexible coupling installation
  
• Propeller" (Be the first to contribute your experience here)
  
• Shaft Alignment
  
• Stuffing box (takes you to a separate section on the stuffing box)
  

Also of Interest

• Diesel Info at Wikipedia
  
• Engine Analysis/survey tips
  
• Engine Manuals
  
• Parts Catalog
  
• Engine Replacement Guide

Westerbeke/Universal now has the owner manuals online. You can download them at http://www.westerbeke.com/Products/OnlineManuals.aspx

Kubota Block Equivalents (you have to scroll down) http://www.ericsonyachts.org/infoexchange/showthread.php?10241-Universal-5432-amp-M40-engine-information&highlight=kubota+block

and

http://c34.org/bbs/index.php/topic,8113.msg56648.html#msg56648