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4108 fuel system

manatee_84

New member
"I need some help/advise regar

"I need some help/advise regarding a 1984 vintage 4-108 new to me last spring. This past winter I updated the fuel filtration system with two racor filters (the small ones with spin-on cartriges and settling bowls below). I also removed a number of ball valves and copper tubing since it was an overly complicated system that has a genset and diesel fireplace added over the years. The GenSet and fire place work, but I am having problems with the Perkins.

One of the things I replaced was the leaky hose assembly from the copper fuel lines to the engine and the return hose assembly from the engine to the copper. Since these assemblies are no longer available, I created my own with Coast Guard approved hose and 1/4 inch steel tube with copper farrels. I took the threaded fittings off the old assembly. If I could get thread to barbed hose fittings, I would just route hose directly to the primer pump.

When I attempt to purge the air from the system, the primer pump makes squirting sounds and I am not sure if this is normal or if I am sucking air or there might be a pin-hole in the diaphram.

So here are a couple of questions:

Should there be some sort of rubber gasket/washer on the end of the 1/4 in fuel line where it attaches to the primer pump?

How do you get to the fittings on the injector pump? It is covered by the heat exchanger.

Has anyone found thread/barbed fittings to connet the fuel hose directly to the engine?

One of the fittings I removed during the upgrade looked like a small check valve. Is this a piece that is required to be in the system just ahead of the primer?

Is it advisable to install an electric lift pump? This is what I had on a previous boat with a Westerbeke.

Any advise would be appreciated. I doubt there is a Perkins Marine mechanic within three or four hours drive time, so I am pretty much on my own.

Thanks
Steve
Kennewick, Washington"
 
Steve I can't answer all of your questions but I recently installed a new lift pump in my 107 and I can tell you that yes there are little rubber grommets that go on the end of the fuel lines going in and out of the lift pump. It also sounds like yes your lift pump may have a cracked diaphragm. Are you getting any fuel into your crankcase? This was the cause of my crankcase filling up with diesel. I have an electric lift pump that I only use when bleeding the system but it's really indispensable if you're doing it alone. A new lift pump is pretty inexpensive, mine cost $60 from the local Perkins repair shop.

Ernie Leep
Islander 36 Trilogy
 
massey ferguson tractors use 3 and 4 cylinder perkins diesel engines , check with a tractor repair shop for parts and mechanical advice
 
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