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alex8 · 20-12-2012, 10:30

Hi,

I topped off for the winter on the water and then started it, it ran roughly for about 10 seconds and died. couldn't restart. changed primary and engine fuel filters (primary was a mess-just bought the boat this year and it always ran great). one downloaded manual says check for blocked vent in fuel cap? i don't see any vent there. i will check fuel tank for drain valve (remember i just started working on this) and think about a tank cleaning as on another thread here. I tried to bleed the system but not sure which nut on top of filter is the bleed one (there is a larger one near the front with a regular head and a smaller one further back with a phillips head (have to get a Z" type short work screwdriver to get to it). I pumped the manual pump on the HP pump for about 4 minutes but could get no flow out of the larger nut which i could open, maybe it was the wrong one. haven't tried bleeding injectors yet. any other suggestions? Thanks

alex8 · 21-12-2012, 23:52

Hi,
not sure how this forum works but i'm replying to my first message to clarify (no one responded). i got the other nut on top of the engine fuel filter off and pumped the manual handle again furiously for some time. still no fuel coming out. how long do you have to pump from the manual lever, anyone? Thanks

**Wotname** · 22-12-2012, 03:48

Quote:

Originally Posted by alex8

Hi,
not sure how this forum works but i'm replying to my first message to clarify (no one responded). i got the other nut on top of the engine fuel filter off and pumped the manual handle again furiously for some time. still no fuel coming out. how long do you have to pump from the manual lever, anyone? Thanks

G'day alex8, welcome aboard. Not sure why no one has posted a response to your question, Yanmar engine threads usually get a good response! This is no way to treat a new poster even if you aren't a new member

Anyway, to your question - I can't actually remember which nut to bleed on the engine fuel filter without having a look at my engine (or manual) and as both are about 2,000 nm away, I won't dropping in before Christmas

. I think it is the smaller one with the Philip's head.

One thing to be aware of is that if the pump doesn't appear to be working, turn the engine over by hand say half a revolution as sometimes the cam that drives the pump is in such a position so the pump lever is already fully pushed in. Your movement on the external lever isn't doing anything in this condition.

I find it easier just to spin the motor over using the starter motor and with the decompression levers operated. This allows the engine to rotate freely and at great speed thus making the fuel pump operate. Don't do this for too long with the cooling water seacock open as it can flood your exhaust.

Ideally you should have either a gravity feed from your fuel tank (or day tank) or an electric pump between the fuel tank and your primary filter. This allows for you to pressure feed (low pressure) the primary filter for bleeding purposes and then you continue on bleeding the secondary (engine mounted) filter and so on to the injector pump and if necessary, the injectors themselves.

Of course to bleed the actual injectors, you will need the injector pump rotating by way of the starter motor (and decompression levers) or using the hand crank.

Best of luck my friend

**GordMay** · 22-12-2012, 04:53

Greetings and welcome aboard the CF, alex8.
See ➥ http://www.cruisersforum.com/forums/...2gm-48200.html

alex8 · 22-12-2012, 06:38

Thanks Wot and Gord. I am a registered user Wot, didn't know that wasn't like membership-I'll look into it. I don't see a pump between my tank and the primary unless its on top of the tank, and don't have remote access to it. The manual lever is not pushed in though, it seems to have enough movement, just can't get anything to flow, after a good bit of furious pumping. I will try turning the crank some to see if I get more reach on it. What would be the difference between using the manual lever and having a pump between primary and tank if there were one, more power? Also you seem to be saying I can just use the starter motor to bleed the primary, secondary, and of course the injectors (or use a manual crank for the first two optionally - I think I may have seen one on the boat, thought it was for some weird winch).
And thanks much Gord for the picture and earlier thread (which didn't come up in my searches). However, it seems different from my engine; the filter housing is on the port side looking at front of engine, not starboad (unless that means in relation to the bow) and the fuel pump (at least where it is shown on my manual and where the manual lever is) is also on that side but further back behind the lube oil dipstick, not near the filter. I'll look for the nut though in the area where the piping is depicted. I am getting a seloc manual in the mail soon hopefully but don't know how clear it will be on this.
I'll have to wait for my son to operate the starter motor while I decompress and open the nuts (again, only for the injectors and not the primary and secondary filters?). Thanks in advance for your help.

Badsanta · 22-12-2012, 06:59

Great advice

dlockhart · 22-12-2012, 07:16

Hi Alex: I have the exact engine and am currently bleeding for a restart after having the injector pump and injectors rebuilt to get rid of an engine knock at idle rpm. I've completely rebuilt this engine in the past and was forced to become intimate with every little piece of it in the not too distant past but the little thing runs great.
The screw on the filter is the large one, you'll notice if you screw it right out it has a bleed hole in it. The book says to pull your throttle out to disengage the transmission and place it in the 50% throttle position. In my case, the fuel is low in the tank and when I removed the injector pump and allowed the line to drain, fuel ran back into the tank. The lift pump would have to be pumped multiple times to lift that distance and would take forever so I drop a line in a can and bleed it from the can locally while I'm setting the injector timing. Afterwards I'll start the engine and the air in the line will get pushed through and back the return line by the little pump while at running speed. By the way, there's a lift pump that's available especially to solve a long cranking starting engine which I put on and the thing starts while you're thinking about starting it now. This isn't related to your current problem but may be nice to know.
Dave

Blue Crab · 22-12-2012, 07:18

I have the YSM12 single cylinder. The added electric pump makes things easier and far faster to bleed, as Wotname suggests. No waiting. No toggling the lift pump. My elec (Yanmar tractor pump from ebay 6psi, I think) pumps right thru the factory manual pump. The sec filter on the engine needs bleedings before the injs, obviously. My bleed screw is the phillips-headed one. In the older threads I found a reference to this type set up using an outboard squeeze bulb before the secondary filter. Easier yet.

**Wotname** · 22-12-2012, 07:37

Quote:

Originally Posted by Wotname

G'day alex8, welcome aboard. Not sure why no one has posted a response to your question, Yanmar engine threads usually get a good response! This is no way to treat a new poster even if you aren't a new member

..........

Quote:

Originally Posted by alex8

Thanks Wot and Gord. I am a registered user Wot, didn't know that wasn't like membership-I'll look into it. ............

Sorry mate, just making an aside comment that you had joined many months back but only posted today (yesterday?)

. So meaning you are an "old" member but new poster.
Have a very merry Christmas.

TexSail · 22-12-2012, 07:45

To check for a blocked vent, maybe just remove the cap and see if it runs OK.

Badsanta · 22-12-2012, 08:43

Dlockhart. Is that a yanmar pump you added or just an aftermarket? Part number ? Many thanks

alex8 · 22-12-2012, 09:15

Thanks All,
DLOCKHART, don't know what you mean by "I drop a line in a can and bleed it from the can locally while I'm setting the injector timing". How do you get a draw from the can? (and i'm hoping i don't have to time injectors since it always ran great and started with no throttle) So, I guess it wouldn't be cool to bleed while running the starter motor?
WOT, that's OK, I joined a while ago before I had a boat just reading the posts. Now I'm actually one of you. I'd do anything to hear the little engine running again.

**Wotname** · 23-12-2012, 06:27

Quote:

Originally Posted by alex8

Thanks All,
DLOCKHART, don't know what you mean by "I drop a line in a can and bleed it from the can locally while I'm setting the injector timing". How do you get a draw from the can? (and i'm hoping i don't have to time injectors since it always ran great and started with no throttle) So, I guess it wouldn't be cool to bleed while running the starter motor?
WOT, that's OK, I joined a while ago before I had a boat just reading the posts. Now I'm actually one of you. I'd do anything to hear the little engine running again.

Nope, you won't have to time the injectors.

Let's go back to basics for a minute.

I am making the following assumptions based on what you have posted; please excuse me if any are incorrect.
This is your first boat.
This is your first time at being a diesel mechanic.
This is the first time the engine hasn't worked for you.
You topped off the fuel tank and the engine started OK, ran for about 10 seconds and died and won't restart.
It had run OK every time prior to this event.
You changed primary and engine filters.
The primary was "a mess" (as in very dirty, clogged etc???)
You have tried to prime the fuel system but can't get any fuel to flow through to the engine filter.

Given that, let's diagnose the problem(s) for the data (assumptions) given.

First problem was that the engine wouldn't run or restart after topping up the fuel tank. It is highly unlikely that topping up the tank has caused this problem so something else has. Most likely cause would be lack of fuel caused by clogged fuel filter. This is, in part, supported by the primary filter being "a mess". Apart from that, there may be other reasons why the engine won't run (like faulty lift pump) but until you resolve your second problem (below), you can't really explore them.

Second problem, after changing both filters, you can't prime the fuel system and as you are aware (or soon will be), the engine will not run until all the air is purged from the fuel system.

The following is just a short heads up on priming the fuel system; it is not a complete set of instructions nor am I diesel mechanic - just like most of us, I am self taught by necessity. You will find heaps of info on CF if you use the custom google search function in the search pull down menu rather than the other search functions. Once you know the basics of bleeding the fuel system, you will find easier and/or quicker ways and shortcuts to do this for your particular setup.

Back to bleeding the system. You have to get all the air out of the system at least up to the injector pump and maybe right though to the injectors themselves. You will either have to pump the fuel through or use gravity.

As you only have the engine fuel lift pump to use, it is a little harder but certainly not impossible. I suggest priming this pump by removing the fuel line at the outlet side of of the primary filter and pouring diesel into the line with a small funnel. Now operate the pump by hand and see if you can pump fuel through it - should only take a handful of strokes to get some fuel moving through it. Keep topping up the fuel in the funnel.

If it doesn't pump, rotate the crankshaft as described earlier and try again. If it still doesn't pump fuel, then your pump has failed - which could be the cause of the first problem. Fix pump!

However, if it does pump, then continue with bleeding by loosening the bleed screw on the engine filter and pump away until only fuel comes out - no air. Tighten this screw and move onto the bleed screw at the injector pump and repeat the bleeding process.

Once there is no more air at this point, retighten the screw.

Don't forget to keep the fuel in the funnel topped up during all this.

Reconnect the outlet side of the primary filter and disconnect the inlet side. Now prime the primary filter by pouring fuel into the filter from the inlet side of the filter and loosening the bleed screw on top of the filter. Again continue until no air comes out, only fuel. Tighten bleed screw.

Now you can either reconnect the inlet side of the filter and try to start the engine or just try to start with the funnel (full of fuel) still connected to the inlet side of the filter.

If it doesn't start fairly quickly, you will have to bleed the injector side of the injector pump. Do one cylinder at a time.
Operate the decompression levers (both).
Loosen the banjo bolt at the injector and rotate engine briskly either by hand
or with starter motor. Continue until fuel is flowing freely and then tighten banjo bolt and stop turning engine over. Repeat for other cylinder.
Return the decompression levers to normal position and try to start engine.

It should start; if not repeat the bleeding process!

Assuming it does start, it may or may not keep running depending on how much air is in the fuel line between the inlet side of the primary filter and the outlet of the tank. Again this air has to be pumped out. This not always easy just using the engine lift pump but it can be done.

As mentioned earlier, having a gravity feed fuel tank is very helpful for bleeding the fuel lines but if your tank is below the engine lift pump, then many people fit a small electric auxiliary fuel pump between the fuel tank outlet and the primary filter inlet. You only operate it when bleeding the fuel system and use it to move the fuel (and air) through the system instead of the engine lift pump. The pump will allow fuel to pass when it is turned off. It isn't necessary but does make the job a whole lot easier and quicker. Just the thing after having to change a primary filter due to dirty fuel in the middle of a rough sea-way!