It's Alive! - Yanmar 1GM10 Repower of Silver Maiden

wynkoop

Member II
Sunday I finally got the nerve up to fire up the 1GM10. Results were generally good.

I connected an electric diesel pump I bought at the auto parts store to a fuel line that ran to a handy 2 gallon portable can.
The pump was wired to the fuel pump line used by the old Palmer.

I turned on the key and let fuel pump through the line and come out before I connected it to the Yanmar. This avoided having to bleed the yanmar which I had run static some months ago.
I turned the key off, clamped down the fuel line at the lifter pump and opened the seacock. Raw water filled the strainer, I advanced the throttle just a notch hit the starter and I was quickly greeted with the banging of the little 1 piston engine.

I ran the engine in neutral through the rpm range from very slow, where it seemed the engine would shake like an earthquake, up through a smooth range, with a slight rough spot in the middle, followed by smooth operation the rest of the way.

A leak in the exhaust caused by not cranking down the hose clamp enough proved the raw water pump was doing it's job, and a rising external temp gauge showed that even though I could not hear the circulating pump over the sound of the engine coolant was circulating.

Not having anything more than idiot light sensors on the engine I purchased a small electronic thermometer off of ebay for about $5. Testing it at home before installation proved it to match up with other instruments I had on hand. The probe for the thermometer is attached to the brass 90 I put between the water out of the engine and the heat exchanger. This is right where the water exits the engine when the thermostat opens. I figured that was a good place for the probe. If anyone has a better idea I am all ears.

During the 20 or so minutes I operated the engine the gauge climbed to 99F. A feel of the input and output hoses on the heat exchanger found a temp nice differential.

Engaging the transmission both directions and running up the RPM a bit each direction gave indication the alignment was good. I did not want to run too fast with the prop engaged as I was operating the controls from the engine compartment so I could keep an eye on things.

Had a little panic as I saw h2o dripping from the engine. Traced it back to the weep hole on the raw water pump. Does anyone have a sense of what a proper drip rate is so I can judge if the pump needs a rebuild?

Next small problem was no alternator output. Not really a surprise as I do not have a Yanmar panel and on looking at the diagram that is where the field voltage comes from. Next trip to the marina the field gets wired directly to my switched circuit that runs the circulating pump. I suspect this will solve the problem. I am also going to toss together a fast little project with a couple LEDs and a salvaged buzzer for the idiot lights. Will probably have to wire these direct as well as I have not been able to locate the connector that mates to the engine harness. Since I am good with electrics and electronics I see no reason to spend $400 on an idiot light panel!

Now for my questions.

1. Is the electric fuel pump needed or will the lifter pump do the job?

2. Does anyone see any issue with putting a T on the tank vent and using one side of the T for the fuel return and the other for the tank vent line to the transom.

3. What do folks suggest for fuel filters external to this small engine? For the test I just used an in-line automative style filter just like the Palmer had, in addition to the filter that was attached directly to the pump input acting as a thread to nipple adapter in the process.

4. Does anyone know of a source for the Yanmar wiring harness connectors that does not cost a small fortune? If not I will make due with a terminal strip.

So I have a little wiring to do, and some fuel line plumbing as well as probably pumping out some of the fuel I just put in so I can examine it in a few days and see if I have tank crud. No inspection ports in my tank.
 

debonAir

Member III
The lift pump should be able to handle the job without help. They're good for a couple feet of lift.

I'd avoid using brass elbows on my engine, even in the fresh water loop, and especially brass fittings from big box stores. Brass and salt water don't like each other - google dezincification for the issues. Bronze elbows are more money but its well spent in my opinion.
 

wynkoop

Member II
Drats.....looks like I have a job to do replacing the brass in the fresh water loop after I find a new home for Silver Maiden.
 

Tom Metzger

Sustaining Partner
2. Does anyone see any issue with putting a T on the tank vent and using one side of the T for the fuel return and the other for the tank vent line to the transom.
Great idea! Run the rejected fuel out through the transom. The price of diesel is pretty low now. o_O
 

Christian Williams

E381 - Los Angeles
Moderator
Blogs Author
Traced it back to the weep hole on the raw water pump.

If you have a grease cup you can try tightening it. The leak is the pump seal, and there is probably a rebuild kit. It may be easier to buy a new pump, as I've done twice.
 

wynkoop

Member II
Tom-

No not run through transom, Replace the 90 degree fitting at the top of the tank with a T. Have the 2 arms of the T vertical and have the top go to the vent while the middle connection goes to the Yanmar and the bottom of course is seated in the tank.
 

wynkoop

Member II
Christian-

Thanks. I suppose this is either a case of while the engine looked new and the guy I bought it from said it only had 5 hours of bench run time, that he lied, or just sitting for years the seal degraded. I have had the engine in storage for 2 years, and the previous owner said he had it sitting for 5, so I am going to figure age related. Will order needed bits.
 

wynkoop

Member II
Christian-

Do you have a source for the complete 1gm10 pump that is not a kings ransom? So far I am mostly finding rebuild kits, and while I rebuilt the Palmer pump, which is of similar design, I would prefer just to pop a new on on and then rebuild the old one to keep as spare.
 

wynkoop

Member II
Well finally found a complete pump in the USA for $240. Still steep, but if I can not do better I will grab it so I have no worries about meeting my marina closing deadline.

Christian thanks for the video. Will watch in a moment....need more coffee first!
 

wynkoop

Member II
Christian-

Looks much like the rebuild of the Palmer pump I did years ago when at the Ericson regatta at shelter island. Not hard, but think I will go with the new pump this go round to avoid any unforseen issues that might put me back to having no power when April 1 comes around. I will rebuild the old pump though for a spare.
 

Alan Gomes

Sustaining Member
This page - http://www.dolphin24.org/yanmar1GM10Flicka.html suggests having a spare on board due to the high rate of seal failure on the yanmar h2o pump.

No more hesitation. New pump will be ordered today. Rebuild kit for the old one in a couple of weeks.
Hey, Brett. Only time for a short reply here.

I can confirm that the raw water pump on the 1GM is junk. Expect to have regular, ongoing problems with the seals. There are some YouTube videos and other things on the web about how to change them yourself. I've not done it yet myself; I've had Depco Pump do it for me. But I'm going to go DIY next time around because this is, unfortunately, just a regular maintenance item on that pump. The Depco Pump people are very knowledgeable and can also furnish you with the seals at a fair price.
 

Alan Gomes

Sustaining Member
FYI--When I get a chance, I plan to provide a blog post about how I redid the fuel system on my 1GM. I eliminated the on-engine lift pump. (Really, just disconnected it. It's still on the engine. I merely removed the lines from it.) I use a Facet electric pump. I also eliminated the on-engine fuel filter (which is a source of failure), since I have a honkin' big Racor 500. The setup, in brief, is: Tank --> Racor 500 --> electric fuel pump --> 2 way valve. The 2-way valve is plumbed as follows: Position 1: Direct to the injection pump; Position 2: Into the injector return line. I use Position 2 for priming the system. (It could also be used for polishing, if I wanted.) Position 1 is the position in which I normally run things. There is, of couse, a switch in the engine compartment to energize the pump for priming.

This is simpler, makes priming the beast a breeze, and removes certain known failure points (lift pump, on-engine fuel filter) that we could discuss later (or that I will discuss in my blog post).
 

wynkoop

Member II
Yep after reading about the yearly rebuilds needed on the 1GM pump I laid down the $$ for a new one and will do a rebuild on the old one. Have looked at the videos and rebuild seems pretty simple like the Palmer raw water pump, but since Silver Maiden has been evicted I am not taking a chance on a problem before I find the boat a new home and move it there.

Having a ready to go spare on hand after I rebuild the current pump will be a good thing and lower my stress level. When a pump needs rebuild, just swap with the spare and then rebuild and make it the spare.

I remember rigging a Rule live well pump many years ago on Silver Maiden while I waited for parts for the Palmer pump to arrive.
 
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