Diesel Engine

The Catalina 34 has had at least three different motors. The M25, a 21hp engine, was installed on the the early models. The M25XP (23 hp) became standard in 1988. The M30, 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 http://realitycheck.me/resources.htm]

Cooling

• Heat exchanger maintenance, including zinc change
  
• Heat exchanger upgrade to 3" version to prevent overheating
  
• Hump hose replacement guidance
  
• 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 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

• 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 the impeller on"?

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 us all, and is subtitled "Yes, you're right ...but we don't tell customers that."
--KWKloeber 08:47, 15 May 2015 (PDT)

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 Includes general engine panel gauge troubleshooting
  
  

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

Exhaust System

• Exhaust pipe replacement
  
• Exhaust Hose Replacement with Pictures 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
• 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 a AquaLift muffler
  

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

• 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

• Transmissions: The right gear while under sail
  
• Transmissions:Hurth Transmission Cable Adjustment PDF file
• Transmissions:Hurth Repair Manual PDF file
• Universal Diesel Model 15 and 25 Service Manual

Universal M-25 & M25XP Alternator Bracket Upgrade & Alignment IMPORTANT

http://c34.org/bbs/index.php/topic,7917.0.html

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
  

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