Diesel Engine

The Catalina 34 has had at least three different engines. 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).

Operators, Parts, Service Manuals AND Factory Service Bulletins AND Transmision Manuals

• Engine and Transmission Manuals and Universal Factory Service Bulletins
  

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

• ONE PROCEDURE TO FLUSH the ENGINE CLOSED COOLANT SYSTEM - from RC's (aka Mainesail aka Rod Collins aka Compass Marine) --

• Replacement part numbers for the engine coolant circulation pump on the M-25, M-25XP, M-25XPA, M-35, M-35A / Note: This is NOT for the newer B-series engines --KWKloeber 7/14/2019
  
• Flow directions in engine cooling hoses (both early and B-series engines) --KWKloeber 2/2/2019
• Why do some of our engines have different Oberdorfer sea water pumps than others, and what about that cir-clip "holding on the impeller"? -- KWKloeber 15 May 2015

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

• 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
• "B engines" FRESHWATER COOLANT PUMPs with 2-1/4" and 2-3/4" impellers by Breakin Away
• "B engine" COOLANT PUMP INSTALLATION NOTES from Breakin Away
• Rebuilding an Exhaust Riser (also from Dave and a C36 skipper [previously posted]) http://www.realitycheck.me/building-...aust-riser.htm

• 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 ?
 

• Recent update: THERMOSTAT BYPASS HOLE 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 that there is a constant coolant flow thru the exhaust manifold when the Tstat is closed.

<<= Click to enlarge

Electrical

• See also: Alternators and Battery Chargers (takes you to another section)
• Cockpit Engine Panel Gauge Tech Reference / Troubleshooting Steps --K Kloeber 11/3/2014
• 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
  
• Thermostat (temp gauge) 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.

• Newest C34 Exhaust with Water Cooled Riser From C-34 owner Bill Shreeves
  
• Repairing an AquaLift muffler (with pictures) From C-30 owner Mark Hamilton
  
• 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?
  

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
  
• 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

• 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  nd they would revise the website.
  I don't THINK so.  :-)
--KWKloeber 21:33, 29 June 2014 (PDT)

Transmission

• Transmission Replacement
• 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
• Transmission & Damper Plate Link (from the Forum) https://c34.org/bbs/index.php/topic,10436.0.html

Misc Projects

• Updated: *Options to Route Crankcase Breather Hose to Air Intake VIEW THE PDF - K Kloeber May 2021
• 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

• 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