Easiest way to prime a 12v71?

[scottinsydney]

Thank you for all of these great answers. There is a solution in each suggestion, but I will be on my own when I do this.

I remember now on my old boat using a tomato sauce (Ketchup) squeeze bottle to fill the line from the fuel pump. But access to the 12v71 pump is a spiders web.

Out of sheer curiosity, if fuel is pumped from the Racor, will it flow (even very slowly) through the stationary fuel pump to the secondary filter and on to the heads?

Fuel barge will turn up in a couple of days.

[davidwigler]

Another suggestion is to fill the secondary filter with Diesel Kleen.

[jmooney]

I have had to start my 12v71’s without fuel a couple of times , once after replacing a blower and removing the engine driven pump and again when all the fuel lines were replaced. The engine bled itself easily. My Racors are mounted high which might have helped, and the secondaries were full of fuel. I don’t recall cranking very long either. These Detroits are much easier than a Perkins where the injector pump has to be bled and the injectors cracked open.

[dottieshusband]

Scott, I call this the priming lug!

[dsharp]

I would fill every filter from a small fuel can, close off the valve at the tank and fill the line with your squeeze bottle, then open the valve. Can you get your hands on a remote starter (push button with 2 wires with alligator clips) so you can crank the engine from the engine room? Give it a small whiff of starting fluid while you crank it.

[SKYCHENEY]

I just top off the filters and crank it. Once it fires, it usually primes the rest of way. If not, top off again and repeat. I don't mess with pumps and cracking lines.

For years, in the 70's and 80's , we would use ether on all of our Detroits. Never had any problems because of it and we owned a bunch of them(trucking and construction businesses). I don't suggest using ether, but I question all of the hysteria over using it.

[scottinsydney]

Thanks again for all the help. The fuel barge arrived this afternoon and 675 gallons later the tanks are full. I've decided to use a little bit of everyones' suggestions to reprime the port motor.

With what I had on the boat and a quick trip to the hose fittings shop, there is now a little 12v71 priming kit. I'll need more hose to recreate Robert's crossover system further down the line. We will prime and start the motors next week when we are back on the boat.


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Sydney Harbour Fuel Barge

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Here's the little 12 volt priming kit I had already made up from a previous boat. A valve, some hose, a 12 volt battery and a car fuel pump.


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5/16" hosetail ready to prime... I'll later add a 90 degree bend and valve to recreate Robert's twin engine crossover priming system..

[racclarkson@gmail.com]

Scott, while you’re at it add a pressure gauge on both adapters. Very inexpensive and an easy install.

[scottinsydney]

So today I primed the Racor and the secondary with the priming pump and kept it running.

The motor started instantly with little white smoke. Being winter, 65 degrees F, the Detroits are generally slow to start and give off a big puff of white smoke. And some hunting.

I am wondering if the easy start was because of perfectly primed heads? And if fuel is actually siphoning back to the fuel tank when motors are cold? Could one way valves solve this?

It would be easy wiring to set up a permanent priming system for each engine that ran a priming pump when you pressed the starter button. Or perhaps an even better / nifty way to wire / operate it would be when you pressed the STOP button for 15 seconds prior to starting a cold engine. The latter option would depend on the position of the fuel solenoid if it was before or after the secondary filter. I can't remember.

Thoughts?

[racclarkson@gmail.com]

So today I primed the Racor and the secondary with the priming pump and kept it running. The motor started instantly with little white smoke. Being winter, 65 degrees F, the Detroits are generally slow to start and give off a big puff of white smoke. And some hunting.I am wondering if the easy start was because of perfectly primed heads? And if fuel is actually siphoning back to the fuel tank when motors are cold? Could one way valves solve this?It would be easy wiring to set up a permanent priming system for each engine that ran a priming pump when you pressed the starter button. Or perhaps an even better / nifty way to wire / operate it would be when you pressed the STOP button for 15 seconds prior to starting a cold engine. The latter option would depend on the position of the fuel solenoid if it was before or after the secondary filter. I can't remember.Thoughts?

Scott, My Hatt manual encourages cranking with stop switch depressed for 15 seconds when motor has not been run for three weeks or more. So much for needing to take it easy on the starter theory. I subscribe to this practice. It’s not to prime the system. Rather, it’s to scavenge the cylinders and build a bit of heat for a cleaner start. I try to always use block heat. Not necessarily for cold starts as much as preheating the oil; that translates to instant starts even in winter. BTW, you already have one-way valves on your racors. And, the fuel doesn’t drain out the heads when you shutdown. Keep it simple.