Dismantling a generator

[stranded]

We have finally given up on ever getting reliable service from our built in Whisper 3.5 diesel generator. Hoping I can dispose of it colditz style myself by taking it apart bit by bit (having disconnected fuel supply, cooling, exhaust and electrical connections) and smuggling the bits ashore on the water taxi. But that depends on the weight of the heavier bits - if I need to get a yard to take out the heaviest bit I may as well ask them to remove the whole thing in one lump. Does anyone have even a vague idea of what sort of weight the heaviest non-divisible chunk is going to be? The engine is a Kubota single pot 276cc and the overall weight is around 100kg.

 

[penfold]

How far are you prepared to dismantle? The crankcase will be the heaviest single engine piece assuming it's cast iron, probably around 10-15kg followed by the crankshaft. The stator and rotor of the generator end will be of the same order of heaviness.

 

[stranded]

How far are you prepared to dismantle? The crankcase will be the heaviest single engine piece assuming it's cast iron, probably around 10-15kg followed by the crankshaft. The stator and rotor of the generator end will be of the same order of heaviness.

Cheers penfold - prepared to go as far as I can with the tools I have - as is no doubt clear, I’ve never so much as changed a spark plug, so not sure what that entails - but if I’ve isolated the fuel water etc and emptied the oil i assume I can just keep unscrewing things until they fall off. Problem of course is access - mostly arms length so 15 kgs or so is probably the max I can lift out of the engine room - sounds worth a go.

 

[LadyInBed]

Can you not dismantle then go and tie up alongside somewhere and put it all ashore in one go?

 

[stranded]

That would be one way. But I am imagining this will be a longer term project as I try to work out how to dismantle each piece - bit like the Christmas jigsaw where you pop in and do a couple of pieces when you have an odd minute.

 

[lustyd]

Just bear in mind the oily stink that’s going to be present until you’re done. The oily smelly bits will come out last.

 

[AntarcticPilot]

Cheers penfold - prepared to go as far as I can with the tools I have - as is no doubt clear, I’ve never so much as changed a spark plug, so not sure what that entails - but if I’ve isolated the fuel water etc and emptied the oil i assume I can just keep unscrewing things until they fall off. Problem of course is access - mostly arms length so 15 kgs or so is probably the max I can lift out of the engine room - sounds worth a go.

Beware of "just unscrewing things". Some parts - for example, the valve gear - have springs under compression, and doing it wrong might result in fairly substantial bits of metal flying around. Get a workshop manual for the engine; they are mostly available online, and will give information to allow the engine to be dismantled in a rational and safe manner.

 

[vas]

+1 on previous posters, just to give a bit more of an analysis of how I'd progress - based on my dismantling in situ of the generator motor (yanmar 2gmf) for a full rebuilt a few years back.
Unless you get also a manual for the generator bit, it's going to be fun removing gen from motor. There will be 6-8 clearly visible screws in the casing (M8 typically from gen to motor) but then there may be another 8-12 smaller ones M6? holding the gen rotor via a thin plate to the crankshaft of the motor.
That's your step one imho. so that the 100kg becomes 40-60 (at a guess). Make sure you have space to manhandle and access the gen bit as that will have to be further dismantled to be managed and removed. The 40 (gen) will split in casing and central rotor shaft/wiring/whatever if you figure out how (probably easy pulling out on the motor side) but wont bring it down to 15kg for sure.
Motor otoh after successfully surviving the removal of the cyl head (as AntarcticPilot explains) will leave you with a fair chunk of metal in the block/crank/pistons. Doubt it's worth taking it apart tbh
I recon you'll end up with a couple 20+kg bits of awkward pieces.
Cant you arrange the whole gen as a "payment" for a lift-out or something somewhere there? and avoid all the oily mess?

V.

 

[stranded]

Beware of "just unscrewing things". Some parts - for example, the valve gear - have springs under compression, and doing it wrong might result in fairly substantial bits of metal flying around. Get a workshop manual for the engine; they are mostly available online, and will give information to allow the engine to be dismantled in a rational and safe manner.

Rational and safe - there’s a new concept to get my head around!
But thank you for the heads up - I will do some research.

 

[stranded]

+1 on previous posters, just to give a bit more of an analysis of how I'd progress - based on my dismantling in situ of the generator motor (yanmar 2gmf) for a full rebuilt a few years back.
Unless you get also a manual for the generator bit, it's going to be fun removing gen from motor. There will be 6-8 clearly visible screws in the casing (M8 typically from gen to motor) but then there may be another 8-12 smaller ones M6? holding the gen rotor via a thin plate to the crankshaft of the motor.
That's your step one imho. so that the 100kg becomes 40-60 (at a guess). Make sure you have space to manhandle and access the gen bit as that will have to be further dismantled to be managed and removed. The 40 (gen) will split in casing and central rotor shaft/wiring/whatever if you figure out how (probably easy pulling out on the motor side) but wont bring it down to 15kg for sure.
Motor otoh after successfully surviving the removal of the cyl head (as AntarcticPilot explains) will leave you with a fair chunk of metal in the block/crank/pistons. Doubt it's worth taking it apart tbh
I recon you'll end up with a couple 20+kg bits of awkward pieces.
Cant you arrange the whole gen as a "payment" for a lift-out or something somewhere there? and avoid all the oily mess?

V.

Thanks for that Vas - I’ve got a lift booked for April, but can’t imagine the generator has any value - if I thought it was salvageable I’d try to find someone who would want it - as you say, perhaps in exchange for helping me get it out, but my understanding is the electronics on these things are made of cheese and having already blown a couple of ks trying to fix it I I just want rid.

 

[stranded]

Just bear in mind the oily stink that’s going to be present until you’re done. The oily smelly bits will come out last.

Yes, I fear that may cause Hilary to crack the whip.

 

[ean_p]

Thanks for that Vas - I’ve got a lift booked for April, but can’t imagine the generator has any value - if I thought it was salvageable I’d try to find someone who would want it - as you say, perhaps in exchange for helping me get it out, but my understanding is the electronics on these things are made of cheese and having already blown a couple of ks trying to fix it I I just want rid.

I think you may be underestimating the intrinsic value of the machine.
Is it accessible to the end of your boom? If so at 100kg then a block on the boom end in conjunction with a beefed up topping lift may well have it out as a job lot either on the water or on the hard.

 

[stranded]

Sadly not accessible to the boom end - it is shoehorned into the back of the engine cupboard above the shaft coupling - centre cockpit, so would either have to come out via the aft cabin then through the mid ships galley kitchen, or be lifted over the engine. Once we got it to the foot of the stair I could rig a tackle from the front end of the boom - did that to replace our 65kg house batteries, but can’t see how I would get it that far in one piece. Thanks for the suggestion though. I’m pretty sure my yard wouldn’t be interested in horse trading over this, but maybe when we are over in Spain/Portugal in the summer I might find someone in a more entrepreneurial small yard who thinks it worth the trouble - there’s no great rush.

 

[penfold]

Beware of "just unscrewing things". Some parts - for example, the valve gear - have springs under compression, and doing it wrong might result in fairly substantial bits of metal flying around. Get a workshop manual for the engine; they are mostly available online, and will give information to allow the engine to be dismantled in a rational and safe manner.

There are valves&springs but no benefit from dismantling the rocker gear as it doesn't weigh much and the cylinder head with valvegear will be <10kg, although depending on the cylinder head bolt arrangement it may be some of the bolts double up as rocker gear fasteners. None of it is getting fired across the engine space as the valve springs are attached to the valves by collets and spring caps. A workshop manual is a good idea as it may give clues about the order in which to remove things, it doesn't even need to be the specific model as long as it's a similar engine by the same manufacturer as they tend to have one way of building engines. An exploded parts diagram can be helpful for visualising how things come apart.

+1 on previous posters, just to give a bit more of an analysis of how I'd progress - based on my dismantling in situ of the generator motor (yanmar 2gmf) for a full rebuilt a few years back.
Unless you get also a manual for the generator bit, it's going to be fun removing gen from motor. There will be 6-8 clearly visible screws in the casing (M8 typically from gen to motor) but then there may be another 8-12 smaller ones M6? holding the gen rotor via a thin plate to the crankshaft of the motor.

At this size of generator the flywheel and the rotor may be on tapers or keyed to the crankshaft and secured with a single axial bolt/nut, separating them may require belting them with hammers while levering them apart.

 

[vas]

I think you may be underestimating the intrinsic value of the machine.
Is it accessible to the end of your boom? If so at 100kg then a block on the boom end in conjunction with a beefed up topping lift may well have it out as a job lot either on the water or on the hard.

+1

ok, the gen maybe dead, but the kubota is fine, so why scrap it? Surely there's a value to it, albeit small, if it was a two pot circa 12hp it could defo be used as main propulsion on a 24-28ft sailboat. 5-6hp not sure where they'd fit in the marine food chain.

 

[stranded]

Thanks - I’ll get a workshop manual and see if I think I can dismantle it reversibly taking into account all the very helpful advice here, or if not whether I can arouse any interest on our travels.

 

[Graham_Wright]

For what it's worth, I bought a Fischer Panda genny with a declared oil-water leak. It was housed in a padded container. That itself has a significant weight. I have hopefully fixed the leak - still to be tested prior to installation. The case and the genny itself were separated but the shock mounts detached from the bolts. They have been refixed.
My scheme for installation involves an extension to the boom with an eye for a block at the end. A handy billy should enable lifting the innards from alongside, swinging over the boat and lowering through the aft hatch. The two will be remated below. The enclosure is too big to pass through the hatch.
I found Fischer Panda UK extremely helpful with information, on line manual sources and provision of the two little sealing rings.
Take some photos before you start stripping!

 

[robert_a]

I have a broken impeller with 2 pcs of missing rubber wings on a mastervolt whisper 8. I can’t seem to find them. Where can they be? I can’t see where the heat exchanger is located. The generator is mounted in a small area. Very tight.
Any advice ?

 

[vas]

would make more sense to start a new thread with the right title I recon!
sorry don't know these generators, so cannot really help.
best if you knew what engine is on it as marinisation most likely will be the same as in other type of installations.

 

[Metalicmike]

Beware of "just unscrewing things". Some parts - for example, the valve gear - have springs under compression, and doing it wrong might result in fairly substantial bits of metal flying around. Get a workshop manual for the engine; they are mostly available online, and will give information to allow the engine to be dismantled in a rational and safe manner.

Don't think he needs to take the valves out.