Help finding step by step guide for bleeding fuel line on M-25XPBC Diesel on my 2002 Catalina 310

Apr 6, 2013
139
Catalina 310 Annapolis
I am going to be inspecting -- and replacing as necessary -- the primary and secondary fuel filters -- on my new to me Catalina 310 either as part of winter layup or spring commissioning. From having previously owned a Yanmar 20GM10F on my last boat, I know that I will have to bleed the fuel line as part of this process. I've seen a reference to a helpful, step-by-step guide that someone posted to this forum years ago for this model Universal but I haven't been able to locate it. Does someone have a link? One of the questions I have is will my model year Universal M-25XPBC require a manual bleed process or is it somehow done via the electric fuel pump with some adjustment to a valve? Thanks in advance for any help or further references! And Happy Thanksgiving.
 

Tom J

.
Sep 30, 2008
2,301
Catalina 310 Quincy, MA
My M25xpb Universal is self bleeding, so no manual bleeding is necessary. I fill the Racor when installing it, then hold the "ignition" key all the way on for 30 seconds or so before starting the engine. You should hear the lift pump ticking as it fills and bleeds the system. The engine should fire right up. I haven't had to manually bleed my system yet ( 1600 hours).
 

Tom J

.
Sep 30, 2008
2,301
Catalina 310 Quincy, MA
Thanks! That is a benefit of this vessel I hadn't known about.
Yes, one of many benefits of the C310! Another thing I love about our engine setup is the incredible access we have to the engine itself. Just lift the companionway stairs, and there it is!
 
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Aug 29, 2016
131
Catalina 2004 310 (Hull #250) BC
Yes, so holding the key on all the way for 30 seconds or so is pretty much normal start procedure anyway.
Funny thing. I noticed mine always fires up right away so I never hold the key...less wear on the glow plugs. Is that normal? Wrong?
 

Tom J

.
Sep 30, 2008
2,301
Catalina 310 Quincy, MA
Funny thing. I noticed mine always fires up right away so I never hold the key...less wear on the glow plugs. Is that normal? Wrong?
I think if the engine fires right up, that is fine. When I lived in Florida, I often didn't need to use the glow plugs. Now that my boat is based in New England, I usually hold the key on for a bit on those chilly mornings.
 
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
Now and then I consider rewiring the switch so that it starts like a car (well, an older car!): Moving the glow plug wire to the start button, and the starter wire to the ignition switch. The existing switch doesn’t have the current capacity for the starter, so it would need to be replaced, but that’s not a big deal.

Any reason that would be a stupid thing to do? I know tradition has a separate start button from the ignition switch, but are there good reasons for doing it that way?

BTW, Happy Turkey Day to all.
 

Tom J

.
Sep 30, 2008
2,301
Catalina 310 Quincy, MA
Now and then I consider rewiring the switch so that it starts like a car (well, an older car!): Moving the glow plug wire to the start button, and the starter wire to the ignition switch. The existing switch doesn’t have the current capacity for the starter, so it would need to be replaced, but that’s not a big deal.

Any reason that would be a stupid thing to do? I know tradition has a separate start button from the ignition switch, but are there good reasons for doing it that way?

BTW, Happy Turkey Day to all.
Interesting idea. Actually, the switch would be wired to a start relay, so it wouldn't be carrying the current of the start motor. It's funny, now that you mentioned cars, that the new cars have gone full circle, and have a separate start button. It's cool to hit that big red button to start the car, just like on a race car.
 
May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
Now and then I consider rewiring the switch so that it starts like a car (well, an older car!): Moving the glow plug wire to the start button, and the starter wire to the ignition switch. The existing switch doesn’t have the current capacity for the starter, so it would need to be replaced, but that’s not a big deal.

Any reason that would be a stupid thing to do? I know tradition has a separate start button from the ignition switch, but are there good reasons for doing it that way?

BTW, Happy Turkey Day to all.
This is a BAD idea the Universal Diesel starters have Very high current requirements on the “solenoid”. In a normal starter it just pulls in a relay with big contacts to spin the motor, which throws out the bendix using centrifugal force.
The universal starter first pushes and holds the starter gear onto the flywheel, then does the relay thing. It takes 30+A to push out the gear and 10A to keep it there. Your switch is probably rated at 7A - well below both the initial startup current as well as the hold current. You can (I have) add another relay (I used an automotive 40/60) before the starter. I found it really helps for quick starts
Did you know early Catalina Diesels had the starter on the key switch? They moved it off and put the glow plugs there when they added the relay on the glow plugs, for reliability reasons.
 
Feb 26, 2004
22,760
Catalina 34 224 Maple Bay, BC, Canada
Now and then I consider rewiring the switch so that it starts like a car (well, an older car!): Moving the glow plug wire to the start button, and the starter wire to the ignition switch. The existing switch doesn’t have the current capacity for the starter, so it would need to be replaced, but that’s not a big deal.

Any reason that would be a stupid thing to do? I know tradition has a separate start button from the ignition switch, but are there good reasons for doing it that way?

BTW, Happy Turkey Day to all.
The issue is not tradition, and may not even be the current capacity of the key switch or the button (which "should have" been specified and installed with the proper ratings).

The larger issue is one of simplicity and needing to bleed the engine without energizing the glow plugs. That's why I asked the question in post #6.

OK, OK, people will say: "But I have a self bleeding engine, what difference does it make?"

It does and it should.

Here's why:


Your boat, your choice. :)

But at least know why and the downsides for such an arrangement.
 
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
Interesting idea. Actually, the switch would be wired to a start relay, so it wouldn't be carrying the current of the start motor. It's funny, now that you mentioned cars, that the new cars have gone full circle, and have a separate start button. It's cool to hit that big red button to start the car, just like on a race car.
I actually measured the current draw for the start relay, and the existing switch is undersized.
 
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Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
This is a BAD idea the Universal Diesel starters have Very high current requirements on the “solenoid”. In a normal starter it just pulls in a relay with big contacts to spin the motor, which throws out the bendix using centrifugal force.
The universal starter first pushes and holds the starter gear onto the flywheel, then does the relay thing. It takes 30+A to push out the gear and 10A to keep it there. Your switch is probably rated at 7A - well below both the initial startup current as well as the hold current. You can (I have) add another relay (I used an automotive 40/60) before the starter. I found it really helps for quick starts
Did you know early Catalina Diesels had the starter on the key switch? They moved it off and put the glow plugs there when they added the relay on the glow plugs, for reliability reasons.
Leslie, all I would be doing is replacing the current push button with a new key switch (with the required higher current rating). The idea of a real starting relay is a good one, and would also eliminate the need for repl the key switch.
 
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
The issue is not tradition, and may not even be the current capacity of the key switch or the button (which "should have" been specified and installed with the proper ratings).

The larger issue is one of simplicity and needing to bleed the engine without energizing the glow plugs. That's why I asked the question in post #6.

OK, OK, people will say: "But I have a self bleeding engine, what difference does it make?"

It does and it should.

Here's why:


Your boat, your choice. :)

But at least know why and the downsides for such an arrangement.
Stu, you’re right, of course, but the issue with the glow plugs is the same whether you energize them with the key switch or a push button. Maybe a better solution is to add an alternative way to power the lift pump for bleeding and polishing?
 
May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
Stu, you’re right, of course, but the issue with the glow plugs is the same whether you energize them with the key switch or a push button. Maybe a better solution is to add an alternative way to power the lift pump for bleeding and polishing?
I do have a push button for turning on the pump, I only use it when bleeding the secondary on engine filter with the bleed screw. This way I don’t need a helper at the key switch.
For the primary I just route the output of the pump back to the tank via a 3-way valve. Before I installed the valve I’d just open the knurled knob and leave the key on for a couple minutes. My M25 came factory wired to run the lift pump when ever the key was on. It was also wired for glow plugs on a momentary toggle switch (no relays) and start was on the key switch.
If you have an early (83 or before) without the knurled knob, it’s easy to get parts to install one.
 
Feb 20, 2013
48
Catalina 310 Channel Islands Harbor
You could make a jumper wire at the oil pressure switch that will activate the lift pump with out heating the glow plugs.
Jeff
 
Feb 26, 2004
22,760
Catalina 34 224 Maple Bay, BC, Canada
Stu, you’re right, of course, but the issue with the glow plugs is the same whether you energize them with the key switch or a push button. Maybe a better solution is to add an alternative way to power the lift pump for bleeding and polishing?
Rob, don't know how far down in that link you drilled. You should follow this one, answers your ? and is like simi's answer, like but not equal, functionally the same. Les ' idea is great, too.

Hard Starting/ Possible glow plug problem?? M35 Engines & Fuel Pump Wiring

Reply #52 on page 4 of that topic begins to discuss the wiring to the fuel pump, how it works, issues with bleeding, and continues to end up describing exactly the issue that Dave addressed in his question.