Who has replaced a generator???

I want to hear stories. New? Used? Did you do the work? About how heavy is a 8-12 kw diesel generator? How much work is involved in the remove and replace processs?

Stories please! Any and all welcome.

8-12kw is more than can be lifted by humans. However it’s not to hard to build scaffolding and a chain hoist to get it up to the main deck. I usually use a forklift to get it on and off the boat. I have never needed to pull the boat out of the water to do the job but if the fork lift can’t get close to you, you will have to get close to it.

Once I had no floor to work with, had to open the windows and built the scaffolding on the outside deck with 12’ 2x4’s running through the boat. Hooked the chain hoist to a 1” pipe that sat on top of the 2x4’s. Then used pipe wrench’s to roll the pipe & load from one side to the other so the forklift could come in the back door and pick the generator off the chain hoist.

Lotta work.


https://www.facebook.com/media/set/?set=a.10206586659585641&type=1&l=0046b03f85


The old Onan was truly dead so we were able to break it down into "manageable" pieces. The big surprise was that the smaller 7.6 kw Westerbeke needed a larger thru hull and strainer so the boat had to be hauled to install those which added to the bill. All the AC wiring and some of the exhaust line also had to be replaced. All this to get the guarantee.


It all cost about the same as the whole sailboat I cruised in for 25,000 miles but worth every penny.

We replaced an 8kw Westerbeke with an 8kw Phasor compact. Weight about 400#. The yard used a forklift with an extra long fork to reach in through the side door. Chain fall to lift. The generator was located in front of the main engine with enough room to pull it without touching the main. The waste tank sits under the gen so I pulled the mounting bed to inspect. Everything was ok and reachable. My generator exhaust system needed to be reworked due to poor original installation. New hoses for water and fuel. Generator output cable, transfer switches, seastrainer, and start battery were reused. New gauge panel fit the old panel footprint.
Total cost was $12.5k.

Thanks guys. I’m under contract with a boat that had bad oil sample from the generator. Im doing research to figure out how big of a job it is. I figured it was too heavy to lift. I believe it’s easy to get to though. Should be able to lift it straight out. It’s got over 5000 hrs on it. I was thinking i could save money by finding a used generator and having it installed.

Steve91T said:

Thanks guys. I’m under contract with a boat that had bad oil sample from the generator. Im doing research to figure out how big of a job it is. I figured it was too heavy to lift. I believe it’s easy to get to though. Should be able to lift it straight out. It’s got over 5000 hrs on it. I was thinking i could save money by finding a used generator and having it installed.

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Before you do anything. Go have a second sample done. Over the years I have seen several bad samples.

BIG CAT said:

Before you do anything. Go have a second sample done. Over the years I have seen several bad samples.

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That’s a good point. I know the generator was a little slow to start. Reminded me of a gas 6.5 with auto choke starting. But once it started it held a load well with no smoke and great oil pressure. I’m having a mechanic check for blow by.

Since it still has oil pressure, I figure the bearings can’t be too far gone, and if it doesn’t have blow by the rings are still sealing. But if it blows the dip stick out of the guy’s hand, well, no bueno.

If it is a 30+ year old genny with 5000 hours, expect Mr Murphy to show up at the most inconvenient time and the electrical part of the unit needs to be inspected also.

Donsan said:

If it is a 30+ year old genny with 5000 hours, expect Mr Murphy to show up at the most inconvenient time and the electrical part of the unit needs to be inspected also.

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It is and I’m sure he will. I was thinking of having the engine just rebuilt but I’m not sure its worth it.

Old unit is definitely worth some good mechanic attention. A bad oil sample is a red flag, but not necessarily a death sentence. If blowby is ok and it carries a load, that is a good sign. Exhaust might not be right, and that can be fixed. Get an oil change and a check-over straight away.

If it does die, don't go used. Go new. Lots of $$$, I know, but every gennie that came out of a boat came out for a reason, and rarely do you know the whole story. Once in your boat, you WILL know the rest of the story!

An old Westy 8kW is about 400-500lb. 12kW about 600(??). If you have a hatch above and a door behind, rigging out is usually no big deal.

I like the Phasors, if you have to go new.

BIG CAT said:

Before you do anything. Go have a second sample done. Over the years I have seen several bad samples.

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Absolutely. I can show you no shortage of bad oil reports (from our local Cat distributor, and for some reason, they all get sent to me) on engines from 300 hp to 1000 hp showing contamination with metals, water, and/or other chemicals that on retesting are magically gone.

Sample drawing technique is everything; it's easy to get contamination from outside sources, or accumulated junk in the tank or valve that is loosed by touching it, etc. that then shows up as high concentration in the fluid.

Before doing anything, change the oil and put some hours on it. Then take another sample, using proper collection technique. From there you can make a decision. It's not like you're going to hurt it if you're already of the mindset of tossing it for a replacement. Unless a bad rod knock is indicating imminent catastrophic failure, of course - something to discuss with a knowledgeable mechanic familiar with that power plant. But you may get lucky with a clean(ish) report.

Also what was bad about the sample? Coolant, copper,iron, fuel, ext? As for the gen end. Check with a local rewind shop and see what it would cost to a clean bake and dip with pre and post insulation resistance tests.

TomandJeri said:

Absolutely. I can show you no shortage of bad oil reports (from our local Cat distributor, and for some reason, they all get sent to me) on engines from 300 hp to 1000 hp showing contamination with metals, water, and/or other chemicals that on retesting are magically gone.

Sample drawing technique is everything; it's easy to get contamination from outside sources, or accumulated junk in the tank or valve that is loosed by touching it, etc. that then shows up as high concentration in the fluid.

Before doing anything, change the oil and put some hours on it. Then take another sample, using proper collection technique. From there you can make a decision. It's not like you're going to hurt it if you're already of the mindset of tossing it for a replacement. Unless a bad rod knock is indicating imminent catastrophic failure, of course - something to discuss with a knowledgeable mechanic familiar with that power plant. But you may get lucky with a clean(ish) report.

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You're 100 % right about poor handling/ technique when it comes to samples. A lot of times it's due to dirty sample gun or not replacing the sample hose every time you pull a sample. I had one of mine come back high coolant that was false. As best I can figure is a rain drop got into it when I took the bottle off my sample gun to put the lid on.

Also for those reading this thread. Cat sells sample port fittings that screw directly into the oil galley. They are dry break so nothing but a rubber cap to remove for pulling the sample. Also they have a customer sample packet that has a sample hise/nipple for use with the fitting. They are disposable and only cost 2 or 3 bucks last I time looked.

An 8K westerbeke diesel is about 550 lb. I dropped mine in with the travel lift. it cost me a hundred bucks. It was a new installation in my boat with a used generator. I did do the work myself, it was not a big challenge once I figured out the 120 volt wiring

motion30 said:

An 8K westerbeke diesel is about 550 lb. I dropped mine in with the travel lift. it cost me a hundred bucks. It was a new installation in my boat with a used generator. I did do the work myself, it was not a big challenge once I figured out the 120 volt wiring

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Mind me asking about what that cost?

How long is a piece of string? Ease to get it in/out depends on the boat. I put 3.5KW in one of my boats by myself. I took a 12KW out of my current boat in three hours with an hour and a half of yard time charged. It all depends. The generator can be halved in weight if you remove the winding from the engine itself.

I did a genset rebuild and new hatch relocation in a four part series here on TF in the Krogen section, beginning with this one:

http://www.trawlerforum.com/forums/s16/project-kk-manatee-gen-relocation-14177.html

You guys all lucky with access to gen. Mine is located on the back of twin engines. The only way to remove is to get one engine out. For now, is working fine, but if will "bit the dust", I will just get 2 external Hondas.

That’s funny, I just pulled my old Onan 12.5 and replaced with a 19kw kohler yesterday and it took about 5 hours and 5 guys to pull and set,

swampu said:

That’s funny, I just pulled my old Onan 12.5 and replaced with a 19kw kohler yesterday and it took about 5 hours and 5 guys to pull and set,
View attachment 80712

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Oh wow. Why did you decided to go so big?

Only 5 hours to remove and replace?

I don’t have a stove, if I ran propane it would have cost in both dollars and stress of having another system to deal with and chance leak. My spare generator has been on the ropes for a long time so when this used unit popped up it just seamed to make since. Now I can buy an electric stove and have plenty of power in reserve

It’s not hooked up yet, the 5 hours was just getting the old unit out and new unit in the boat and down the hole

Used vs New

I'm currently in a Houseboat but am going to transition to a Trawler in the future. I will second the opinion not to buy used. The previous owner to my boat put a used Westerbeke 15kw gas gen in about 3 years ago and now it has thrown a rod. He didn't want to spend the money on a new one and now Westerbeke isn't making any gas gens between 10 and 15KW and there isn't a new one to be found. Seems like Westerbeke is the only company making gas gens now and I'm going to be forced to buy another used one. I haven't found anyone that can rebuild the motor since they can't find parts. I would go with a diesel but can't get get diesel delivered on the lake. My Honda is fine for now but I'll need something larger to run the AC this summer. Anyone know where I might find a new 10-15kw gas gen?

Onan 12 to fisher panda 15

Did this last year...1990 Onan 12kw was removed and installed fisher panda 15kw
Ours is access through cockpit so liftin it in and out was done by yard...we did the discount and install

This project grew into upgrading the house battery system and inverter, and battery switches as well as new sea strainer, external fuel filter

As you start taking things apart you have access and see things like in our case battery cables and switches just worn and corroded, house battery bank was not configured with buss bars which snow that we have seeing much long run when on inverter
Old internet was tripping GFI at doc and charger we found was over
Charging so swapped that out

Did a gensep for the exhaust which was a pain to do but very happy with how quiet the unit is when it runs

We did double motor mounts meaning a platform with mounts and the. The sounds shelled and then another pair of mounts ...no noticeable vibrations like we use to have

Fisher panda has a remote panel that was larger so that cause some changes in location from the prior one but nothing crazy

Very happy with Fisher panda and finished result on all the work we did...just expect the project to grow and take twice as long as any estimates you have....we hit issues with getting the gensep, had do a custom lift muffler that was wrong the first time, and so...lots of pieces to this puzzle doing it in the winter was great as we took our time and did it right

I replaced my Bimini top with three 320W solar panels this summer.

Over a four-week period away from shore power we only had to run the genny once for an hour. That day it was overcast and we had not moved for a couple of days.

We cook with gas but use the dishwasher every day.

When my 45 year old Onan dies I don't plan to replace it.

Xlantic said:

I replaced my Bimini top with three 320W solar panels this summer.

Over a four-week period away from shore power we only had to run the genny once for an hour. That day it was overcast and we had not moved for a couple of days.

We cook with gas but use the dishwasher every day.

When my 45 year old Onan dies I don't plan to replace it.

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Running air conditioning?

Not all situations are the same.

psneeld said:

Running air conditioning?

Not all situations are the same.

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Agreed.

We only run the AC in port. On the hook we just have the fridge, freezer, dishwasher, lighting (mostly LED), charging the portable electronics and, occasionally, the clothes washer.

If you're not at a yard the easiest way to move a 10kw+ is the hire a mover that specializes in equipment. Often called drayage companies, they have the tools, equipment and gorillas to get the job done without damage. And they have insurance. I'm removing my 2 14kw generators and putting in a Detroit 20kw. And that's how an old guy does it.
On smaller generators separating the motor from the generator really gets the weight manageable.