Fuel Injector Pump Leaking

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Joined: 11/2/20
Posts: 2
Fuel Injector Pump Leaking

Hello everyone! I have a Catalina 36 Mk II 1996. I have the Universal M-35(A) engine.

A few months ago I noticed a slow diesel leak. Just the other day I discovered it was my injector pump. At least 3 of the 4 delivery valves are leaking at their base where they meet the pump (here's a generic diagram).
Pump cross-section.jpg
At a friend's suggestion, I tightened the delivery valve holder. This immediately caused the leak to double in volume at least. I think I cracked the o-ring...

So now I need to swap out the o-rings on my injector pump and possible any other wearables. The only issue is that our Universal engine manuals are rather lacking. In the parts list for the M35 it lists: Injector Pump Universal 302494. However, when I called Westerbeke and asked for further parts, they only told me that they bought it from someone else (no mention of what pump it is, they said they couldn't get that info...).

Speaking with many injection pump repair shops they tell me there should be a number and company name on the backside (the long side of it facing away from the cylinders). However, after slowly taking some paint off I don't see anything. They said it's possible there was a tag, and my current theory is that it fell off. Here's an image showing where this number should be: 
Does anyone have any idea what fuel injection pump the M35 uses? Or what this 5 digit number is? If you have an M35, could you check to see if there is a plate on the side? The o-rings and copper washers, and springs might cost me about $40, while taking it in to an injection pump shop may cost me $1000... 

If we can figure this out, I'll post what I've learned so others can pick up similar spares and make similar repairs! Thanks!!!

Joined: 11/2/08
Posts: 46

I am having the same problem.  Last weekend I replaced the injectors.  The nut on the first injector delivery value seemed loose, so I tightened it.  I don't think I used too much force, but I heard a "click," and now it weeps diesel from that nut on the injection pump.  My engine is an early 30hp version of the m35.  It is the same engine used in the Kubuta B9200 tractor.  Messicks has a good online parts catalog.  I have included the picture of the injection pump.  I am planning to replace the gasket (050) and the o-ring (070).

Has anyone done this?  Do you have any tips.  I know the fuel injection pump has tight tolerances so I don't want to break anything.



Ron St. Onge

1995 Catalina 36 MKII Hull 1384

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