New M25xpb

[Jemmag9]

Hello,
I just got a new m25xpb installed in my c-30 after the m25xp lost the drain plug and seized.
To start the motor you need to press the preheat button then while holding that for the appropriate time you need to keep it pressed and then hit the start button. When I do that the boat won’t turn over I think due to so much of a load on the batteries. I have the two batteries on all and it won’t turn it over. It will start if I let go of the preheat and wait then hit both preheat and start quickly at the same time. I was thinking about re-wiring it so the preheat button doesn’t need to be pressed at the same time.
Has anyone had a similar problem.
Thank you,
Jeremy

 

[kappykaplan]

You could momentarily release the preheat switch, then press the start button, and repress the preheat switch. I've found that works most of the time on my boat.

 

[Stu Jackson]

I was thinking about re-wiring it so the preheat button doesn’t need to be pressed at the same time.

That makes sense and was/is the way my M25 is wired. The later M25XPs were wired similarly, the only change being with the fuel pump wired thru the oil pressure switch. That change had nothing to do with your issue.
I am not personally familiar with the M25XPB, but it sounds odd that it came wired that way.
The C310 skippers use this forum as their "website" and should know.

 

[Jemmag9]

Thank you

Jeremy

 

[Ward H]

I've heard of some boats wired that way but I would change it. I'm sure there are other threads about it. Supposedly it was wired that way to prevent someone from trying to start the boat without preheating the plugs and cranking too long and drawing water into the muffler, then engine cylinders. My boat doesn't require the both at the same time. If it were my boat I'd change it but I'd also look into the wiring connections, battery conditions, etc. I think it should crank with no problem if everything was up to par.

 

[Capt jgw]

It's a lot more convenient to have the start button wired independent, if the engines already hot you don't need preheat. Just hit start and go. If it doesn't start right away then go back to preheat for a few seconds. It should be just a simple wire swap on the back of the panel.

 

[jviss]

This is also how Westerbeke, who owns Universal, wires their panels. It is very easy to change to separate preheat and start circuits; my recollection from reading the schematic is that it only requires a screwdriver, no new wires, etc.
or
That said, these engine controls are quite primitive. A modern (i.e., later 20th century) diesel control would measure block temp and air temp, and determine how much preheat was required, and apply that automatically before automatically engaging the starter, once the start command was issued. Diesel generator controllers do this. I "intuit" this by recalling when I last ran the engine, and how cold it is outside. It's highly dependent on the engine. The MX25 (Kubota D850/950) seems to need preheat no matter what. My Mitsubishi-based Westerbeke hardly ever needs preheat.

Another place to look is the wiring. I don't know how they are wired now, but on my '84 vintage M25 the preheat wire ran a long way through a couple of connectors, and was very lossy. I added a preheat solenoid and this made a dramatic improvement - 10 seconds preheat versus 30+ before. As others have suggested, you should also check all of your connections, and your wires, for corrosion, looseness, etc.

 

[dmax]

My boat requires the glow plug button to be pressed along with the starter button like yours and it has no problem turning the engine over with both engaged - you're not getting enough power to your starter. The C30 does have some long wiring runs so be on the lookout for power loss. You should eliminate the Ammeter in your instrument panel if not done so already - check out this article by MaineSail if you're not up on the engine panel upgrades that should be done:
Universal Diesel Engine - Wiring Harness Upgrade - Marine How To
.

 

[weekendrken]

Jeremy

The XPB starting/preheat/fuel pump circuits are COMPLETELY back-asswards compared to the M-25/XPs. They are wired similar to the M25-XPAs.

What cockpit panel do you have with the XPB? Westerbeke or Seaward -- who installed it/rewired it for the XPB?

There's many questions as to why you have a no-start, "starting" with the harness and btty cable sizes, etc . I see this ALL the time.

Suggest you post the Q.? over on the official IC30A forum

Catalina30 groups.io Group

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-- I really don't monitor this forum because getting logged on is a dog -- I can't get in half the time (web times out) or can't get to the forum, or to the particular thread. Everything times out.

Ken

 

[Jemmag9]

Hello,

Thanks everyone for the answers and ideas. It turns out the vent from the new pss shaft seal was draining into the exhaust then backing up into theengine causing it to not turn over according to the mechanic. After re-routing the vent tube and adding a anti siphon valve the motor starts with the preheat and start button pressed at the same time.

Jeremy