What model Universal diesel in 2002 Catalina 310?

Apr 6, 2013
Catalina 310 Annapolis
I am having a hard time determining if I have the Universal model M25XPB or the M25XP. Can someone who has a 2002 (or a 2001 or 2003) Catalina 310 tell me what Universal diesel model they have? I am trying to figure out how to bleed it and the M25XPB is supposed to be self bleeding. Thanks! Is there an easy way to tell the engine model number?

Oct 4, 2014
Catalina 310 73 Monterey
Should be the XPB, that it what mine is and it is a 2000 C310.
According to one online source I found it should be on the exhaust manifold.
It is supposed to be self bleeding if the lift pump is working OK. It's been a bit since I had to mess with mine, as I remember there is a return fuel line off the injector pump that bleeds the pump. It turned out that wasn't my problem, the injector pump itself failed internally.
At it's core, it is a Kubota tractor engine, I have the cross-reference chart somewhere that lists the Kubota version. Instead of $1500 for an overhauled injector pump from the Universal distributor, the local industrial diesel shop rebuilt mine for $500 parts and labor. He does enough of them he had the parts in stock.

Good luck!
Apr 6, 2013
Catalina 310 Annapolis
Thanks! Very helpful. Previous owner had the service manual for the M25XPB but the listing for the boat (I just bought it last year) says M25XP. I imagine these are such similar model numbers people get confused. It may be that one difference is the M25XP has a bleed valve on the high pressure pump with a knurled knob and I guess the M25XPB doesn't. I will check that next time I am on the boat as well as the exhaust for the model number. Thanks for the tip!
Jan 23, 2021
Catalina 30 6352 Newport Beach

If you can get to your boat, you should have a metal tag like this on the top of the engine.
Good luck!


Feb 14, 2017
Catalina 310 211 Lake Guntersville, AL
You have a XPB, no fuel bleeding is required. There are very few 310s with different motors, hull one for sure.
Feb 26, 2004
Catalina 34 224 Maple Bay, BC, Canada
What does it matter what other people have in their boats? The ONLY thing that counts is what YOU have in YOUR boat, which is your question, right?

Therefore, learn to identify the engine you have with a little research and homework.

You could take a picture of the front of your engine and share it with us and we could tell you.

You could go to a reputable website that shows the engines in photos, like this one: Sailboat Engine Parts and Boat Parts- TOAD Marine Supply

The M25XP and XPB, as you've learned, are different engines. The XPB has the raw water pump on the port side underneath the alternator. The XP has the rw pump on the starboard side.

Happy learning.

In either case, bleeding is EASY. On the XP, you just turn a knob. This is not rocket science. Just so you understand, I put off bleeding my M25 for a full year when I bought the boat in 1998 because I had the fear of never being able to start it up again! Really.

But 1998 was just about pre-internet days. Now, there is no excuse.

I learned that even on my M25, all I have to do is turn a small knurled knob to bleed the engine. NO muss, no fuss.
Apr 6, 2013
Catalina 310 Annapolis
Thanks! Based on your description re: orientation of the raw water pump relative to the alyernator, mine is the XPB