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Generator engine rebuild


woodylmiller

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I have a 10kw gen set.  2100 hours on the clock.  No problem putting out current.  Problem is excessive smoke during start up.  I had a code one time of "over prime", had that checked out and they said no, it was 3 bad pre-heat coils.  OK, makes sense.  Replaced the 3 coils.  A little better but not much during start up especially if it's cold out, freezing or below.  It seems to me 2100 hours is not enough to need a rebuild.  BTW, valves were checked and I was told they were OK.  What is your opinion?  Maybe a rebuild of the engine is in order?

I am not the original owner.  The gen had 1600 hours when I bought it.  I've done the oil changes and had Cummins do the 1000 hour service.  Any good source for a rebuild engine?  I can run all three A/C's at once.  I turn one off if we are using the microwave or the dryer (washer also???), the EMS system won't allow everything at once.  So I'm confident about the the generator being able to handle a full load.  Just need an engine, maybe.  Thanks for any advice.

Woody Miller

09 Dynasty Regal IV

PS: good thing there are still blank checks in the checkbook.  lol.

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Does it smoke after warmed up under load?  

If not, then it does not need a rebuild.  Some of these small Kabota and Isuzu diesel engines have over 10,000 hours. 

Keep the oil changed and a clean air filter.  I like to use Rotella T6 synthetic oil in the generator just because it starts better.  

You mean they replaced the three glow plugs. 

Do you prime it by holding the start switch down for several seconds, then rock the switch up to start?  They will smoke when cold but should stop once running and warm.  

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I have 7.5 and it has 2585 hrs on it. The cold and altitude will effect any diesel. They are not turbo charged so that doesn't help either. My does the same thing in the cold but once it warms up it's clean. If it still will make ratted power after warmed up and not blow smoke it's fine. 

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If you only issue is a little smoke on startup and it's not using oil you should be good to go.

I would have a compression check and injectors cleaned before I would be thinking about an overhaul.

Jim

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4 hours ago, vito.a said:

Does it smoke after warmed up under load?  

If not, then it does not need a rebuild.  Some of these small Kabota and Isuzu diesel engines have over 10,000 hours. 

Keep the oil changed and a clean air filter.  I like to use Rotella T6 synthetic oil in the generator just because it starts better.  

You mean they replaced the three glow plugs. 

Do you prime it by holding the start switch down for several seconds, then rock the switch up to start?  They will smoke when cold but should stop once running and warm.  

Exactly 💯 percent 

And the fuel filter, air filter.

You should have 8 to 10 thousand hrs in the engine itself. 

Fresh coolant 

Clean radiator 

Change fluids and filters often .

Run often, they were born to run.

All good advice above.

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A diesel is going to smoke a little until warmed up.  Those engines should easily go 10,000+ hours with normal maintenance.
Unless it's using enough oil that you have to keep topping off on a frequent basis, I wouldn't worry about a little smoke.

Edited by dl_racing427
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11 minutes ago, dl_racing427 said:

A diesel is going to smoke a little until warmed up.  Those engines should easily go 10,000+ hours with normal maintenance.
Unless it's using enough oil that you have to keep topping off on a frequent basis, I wouldn't worry about a little smoke.

And good 👍 morning 🌄

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I knew the Onan 7.5 K on our coach was toast when we bought it and I had just planned on having the engine rebuilt.  Took it to Cummins in Spartanburg where they charged us $750 for a diagnosis, informed us they don't rebuild those engines and then we proceeded to have a new 8 K installed.  $10,000 later, had a new generator/engine. Our maintenance is done meticulously!

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A little smoke on a cold startup (my 10K does this) is normal and not a indication of needing a rebuild. I would say 10,000 hours is on the low side of how many hours these diesel generators will last…probably closer to 20,000.

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Thanks to all.  And yes, once it has run a minute or two the smoke clears.  Only smokes at start up.  Yeah, three glow plugs were replaced, I called them coils.  It could well be the case that the shop that replaced the glow plugs would have liked to have sold me a new gen set for $12k plus labor.  My feeling is  that the diesel engine should run for many more thousands of hours.  In cold weather it could well be the case that the engine cranks before the glow plugs have had a chance to get hot.  

Very good news, that leaves a blank check to pay for 8 new tires.  Yay!!  Just need to arrange a trip to a state with no sales tax.  Oregon is not too far away.

Woody Miller

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12 minutes ago, woodylmiller said:

Thanks to all.  And yes, once it has run a minute or two the smoke clears.  Only smokes at start up.  Yeah, three glow plugs were replaced, I called them coils.  It could well be the case that the shop that replaced the glow plugs would have liked to have sold me a new gen set for $12k plus labor.  My feeling is  that the diesel engine should run for many more thousands of hours.  In cold weather it could well be the case that the engine cranks before the glow plugs have had a chance to get hot.  

Very good news, that leaves a blank check to pay for 8 new tires.  Yay!!  Just need to arrange a trip to a state with no sales tax.  Oregon is not too far away.

Woody Miller

Point S in Astoria OR. is a good place to buy your new tires. 

Jim

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If you don't already have one it's good to carry a spare fuel pump.  From my experience they last about 1,000 hours and are fairly easy to change on the 10kw generator via the side access panel.

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Good point Frank.  We did find out that you need that little pump for the thing to work.  Lost power to it once, bad connector up at the top where all the electrical stuff is housed.  Installed a second switch to power the pump if it ever loses power again.  Way cheaper than the hourly rate we paid to first guy before the lack of voltage was discovered.  As I recall there are quite a few bolts holding all the covers on.

Woody Miller

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On 6/19/2021 at 9:56 AM, woodylmiller said:

Thanks to all.  And yes, once it has run a minute or two the smoke clears.  Only smokes at start up.  Yeah, three glow plugs were replaced, I called them coils.  It could well be the case that the shop that replaced the glow plugs would have liked to have sold me a new gen set for $12k plus labor.  My feeling is  that the diesel engine should run for many more thousands of hours.  In cold weather it could well be the case that the engine cranks before the glow plugs have had a chance to get hot.  

Very good news, that leaves a blank check to pay for 8 new tires.  Yay!!  Just need to arrange a trip to a state with no sales tax.  Oregon is not too far away.

Woody Miller

Is the generator engine a Kubota?

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So smoke can be caused by several things, since you have pages of unused checks have the injectors checked. A healthy injector makes a spray which consist of tiny fuel droplets that ignite from the combustion pressures, a dirty injector sends out a stream of fuel which has a longer burn time. Good news is there are only 3 of them, rather than just replacing them I would want them to test there pop off pressure so you know which one was out of spec. 

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My genset (7.5kW with 3 cylinder Kubota diesel)  smokes at start up and clears in a minute or 2. This the same as my Kubota diesel tractor (3 Cylinder as well) which does the same thing and has since new.

Perfectly normal.

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