Steps to start diesel generator

[Carpediem44DB]

The 21KW Kohler on my 506 is crazy simple and fast starting. I merely engage the momentary toggle switch on the power panel and it lights off instantly. My Onan on the 44 went through what seemed like 30 seconds of preheating no matter what the ambient temperature. The only thing I really do before using the genny is to make sure all of the AC systems are switched off and then load the genny one circuit at a time after the genny has had a few minutes to warm up and stabilize.
I also shed the loads before shutting down just as a best practice. Not sure if it really makes a tangible difference.
CD

 

[yobub]

@mrsrobinson It may be a little different with your switch panel, but on my Westerbeke, which I start from a westerbeke panel, I have to hold preheat for 20 seconds or so, then push start and preheat at the same time, per my westerbeke manual. If I don't push preheat and start at the same time, the unit will not start.

You might try starting the generator directly from the switches on the generator first to eliminate the sea Ray switch configuration as being part of the problem.

 

[b_arrington]

The 21KW Kohler on my 506 is crazy simple and fast starting. I merely engage the momentary toggle switch on the power panel and it lights off instantly. My Onan on the 44 went through what seemed like 30 seconds of preheating no matter what the ambient temperature. The only thing I really do before using the genny is to make sure all of the AC systems are switched off and then load the genny one circuit at a time after the genny has had a few minutes to warm up and stabilize.
I also shed the loads before shutting down just as a best practice. Not sure if it really makes a tangible difference.
CD

I do the same thing with the loads, more so at startup. I also let the generator come up to temp before adding any load. When shutting down I remove all loads and let it run for 2-5 mins to cool down.

My Onan seems pretty simple to start in comparison. Turn on the breaker and press the remote start button until it fires up. Takes maybe 10 seconds. It’s also very quiet. We have no problem with noise. It has a sound shield and a water separating water lift exhaust system.

 

[fwebster]

There are some mechanical things to try to quieten the Diesel Westerbeke Generators. My 450Da had an 8KW Westerbeke and it wan't terminally loud, I suspect because it is physically further from human inhabitants than on a 40DA or a 380DA.

The Westerbeke diesels are old school mechanical engines so the diesel knock is present and obvious. To minimize that, be sure the governor is set correcrtly and the injectors have the correct spray pattern and test properly on a pop test. Neither of which are user or owner addressable maintenance. The pop test must be done in a diesel specialty shop that is properly equipped. The injector test stand is usually in a "clean-room" since injector and pump repairs are also done in the same environment. Any injector I have rmoved must have new crush rings or gaskets used when the injector is replaced or the injector must be seated in a the pop test on injectors is usually freshly reamed injector seat. The other noise source on Westerbeke generators is loose valve lash adjustments which can be don'e by any competent mechanic…..takes about an hour if the cylinder head is re-torqued and it should be anytime the valve cover is removed. The injector pop test is not expensive……..$~95 unless the injector needs to be repaired. Most shops won't just repair an injector, they will rebuild one so that all t he components meet new spec.

So……going thru the rudimentary Westerbeke quietening steps is inexpensive, just a hassle because you will need a diesel shop and mechanic to do most of it.

 

[mrsrobinson]

Thanks @fwebster

She fired up and ran great during the 1-hour trip to St Michael's. Would not start when we left to come home. Even when it started on Friday it took six or seven times trying. I didn't crank it for more than 8 seconds each time for fear of ingesting water.

The way I read and interpret your injector pop test comment, sounds like the generator needs to be out of the boat? Are any of the things you shared also symptoms of it not starting easily?

 

[fwebster]

Did you hold the preheat switch down when cranking? The preheat switch also removes the safeties that shut down the engine for overheat and low oil pressure so the generator just about won't spin fast ewnough to generate enough oil pressure to close that safety switch without holding the preheat switch.
If you just assumes the generator was warm enough and failed to hold the preheat switch down until the generator starts and smooths out, it is very hard to get them to crank up.

Bad glow plugs will also prevent starting.

 

[dtfeld]

I'm simplifying, but these things require good fuel, air and compression to start, and occasionally a little preheat to help the process. So, just a few diagnostic.

Fuel - Have you serviced the fuel system. There are 3 fuel filters on the generator, the primary is the Racor, then there is the inlet filter right before the lift pump (I think its only a screen and removed in a lot of cases), then the canister/element. At a minimum, the Racor and the on engine element should be serviced (I would say checked/serviced, but might as well just replace...same effort involved).

Also, can you confirm hear the lift pump clicking?? If not the pump may be contributing to your starting issues. The pump is a simple and cheap ($20 item) if not pumping.

Compression - The way you get good compression (and the heat to start these engines) is a good strong battery and starter that spin the motor. If it spins slowly you may not get the compression fast enough to ignite the fuel. Solution have the gen start battery load tested.

Preheat (Glowplugs) - The final thing you can do is verify the glow plugs are powered and actually heating. You can verify power with a simple volt meter on the glow plug bus bar. Should be 12VDC. If you have power, you need to verify each plug is actually working (I had one dead one and it made cold starting a little harder) Yiou can pull these, they are just like a spart plug, and I put a little high temp anti seize before reinatlling. If you connect to a 12V battery they will get VERY HOT.

 

[mrsrobinson]

Did you hold the preheat switch down when cranking? The preheat switch also removes the safeties that shut down the engine for overheat and low oil pressure so the generator just about won't spin fast ewnough to generate enough oil pressure to close that safety switch without holding the preheat switch.
If you just assumes the generator was warm enough and failed to hold the preheat switch down until the generator starts and smooths out, it is very hard to get them to crank up.

Bad glow plugs will also prevent starting.

Yes, I held it down prior to trying to start, also while trying to start.

I do not hear any clicking while trying to start. I just purchased the boat, only service history I have on the generator is replacing the water pump

You may be on to something with the battery, it doesn't sound like the engine spins over fast to me, though I'm new to this engine so it could be normal.

 

[fwebster]

Diesel engines are compression fired, not spark fired. What that means is the batteries must be strong and fully charges so the starter can spin the engine fast enough to explode diesel fuel. A weak battery will let the engine drag and have a hard time turning fast enough to ignite the fuel charge.

If you doubt the battery…..any of the batteries, separate them from their battery bank, then load test each battery. For diesels you should have 12.4+ VDC on each battery; below about 11.8v and you may have trouble cranking.

 

[dtfeld]

I will also add that the fuel system cannot have any air leaks. All the fitting and filters etc need to be tight.

I mention this, because I changed fuel filters a few days ago, and I didn't get the cartridge filter retaining ring tight enough and I was having trouble starting and keeping the genny going. I tightened that retaining ring and all is good in the world.

The fact that once you get it started, it runs well, indicates its likely some small detail (like the filter not on tight or too restricted), not a major issue.

 

[mrsrobinson]

We were back on the boat this weekend for the first time since this post when I tried to start the generator. It started on the second try and ran flawlessly the entire trip. When we left this morning, it again started on the 2nd try and ran fine on the trip home.

I was prepared to start doing some diagnostics, but I guess I got lucky.

 

[mrsrobinson]

I'm simplifying, but these things require good fuel, air and compression to start, and occasionally a little preheat to help the process. So, just a few diagnostic.

Fuel - Have you serviced the fuel system. There are 3 fuel filters on the generator, the primary is the Racor, then there is the inlet filter right before the lift pump (I think its only a screen and removed in a lot of cases), then the canister/element. At a minimum, the Racor and the on engine element should be serviced (I would say checked/serviced, but might as well just replace...same effort involved).

Also, can you confirm hear the lift pump clicking?? If not the pump may be contributing to your starting issues. The pump is a simple and cheap ($20 item) if not pumping.

View attachment 125053



Compression - The way you get good compression (and the heat to start these engines) is a good strong battery and starter that spin the motor. If it spins slowly you may not get the compression fast enough to ignite the fuel. Solution have the gen start battery load tested.

Preheat (Glowplugs) - The final thing you can do is verify the glow plugs are powered and actually heating. You can verify power with a simple volt meter on the glow plug bus bar. Should be 12VDC. If you have power, you need to verify each plug is actually working (I had one dead one and it made cold starting a little harder) Yiou can pull these, they are just like a spart plug, and I put a little high temp anti seize before reinatlling. If you connect to a 12V battery they will get VERY HOT.

Ghosted by yet another mechanic so I will be picking this one back up on my own. I replaced the Racor and the ELEMENT you circled June 2022, about 50 hours ago. I was not aware of the INLET FUEL FILTER. I will need to find new one, and then find it on the genny to replace.

 

[dtfeld]

Ghosted by yet another mechanic so I will be picking this one back up on my own. I replaced the Racor and the ELEMENT you circled June 2022, about 50 hours ago. I was not aware of the INLET FUEL FILTER. I will need to find new one, and then find it on the genny to replace.

Dumb question. When was the generator battery replaced last? A fresh battery made a pretty dramatic difference in starting on mine. Spins the motor a little faster and gets the heat to combust up faster.

 

[mrsrobinson]

Dumb question. When was the generator battery replaced last? A fresh battery made a pretty dramatic difference in starting on mine. Spins the motor a little faster and gets the heat to combust up faster.

I wish I knew, I bought the boat a year ago, batteries were already in there. I have a receipt from the previous owner for batteries, but I don't know which ones he replaced.

 

[dtfeld]

I wish I knew, I bought the boat a year ago, batteries were already in there. I have a receipt from the previous owner for batteries, but I don't know which ones he replaced.

Based on what your saying about genny starting, but only on second try, and not knowing the age/condition of the start battery, I would replace that battery first before digging into anything else. Made a big difference in starting of mine. Between the glow plugs and the starter, these little diesels take some omph from the battery to get started.

 

[mrsrobinson]

Will do, what battery do you recommend? And how can I tell which one it is in the battery bank?

 

[dtfeld]

Will do, what battery do you recommend? And how can I tell which one it is in the battery bank?

View attachment 145272

Generator is its own bank, one single battery. Its a Group 31 in my boat, but may be a Group 27 in some It easy to identify as it has thinner battery cables running to it, and does not have a jumper for a second battery. In My boat it is the outermost battery, and therefore easily changed.

I'm a fan of the Duracell Marine AGM $215 @ Sams. I'm getting 8-9 years out of them. Go online to see what locations have them. Made by Deka and they charge a lot more for some other brands that are the same battery under the label.

 

[Steve S]

Will do, what battery do you recommend? And how can I tell which one it is in the battery bank?

View attachment 145272

On my 400DB, the Generator battery is separate from the main battery bank. Gen is Starboard and mains are Port next to the genny.

 

[mrsrobinson]

Generator is its own bank, one single battery. Its a Group 31 in my boat, but may be a Group 27 in some It easy to identify as it has thinner battery cables running to it, and does not have a jumper for a second battery. In My boat it is the outermost battery, and therefore easily changed.

I'm a fan of the Duracell Marine AGM $215 @ Sams. I'm getting 8-9 years out of them. Go online to see what locations have them. Made by Deka and they charge a lot more for some other brands that are the same battery under the label.

View attachment 145273

I should not need a deep cycle for the generator starting battery though, correct?

 

[dtfeld]

I'd have to look at the spec, but I'd go back with at least what was in there, but the more MCA, the better