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Kubota generator hard starting

July 05, 2010, 09:13:29 pm

So far today we've fixed my water heater and fridge, sort of, onward to the next problem:

My powertech generator with the Kubota diesel engine is hard starting.  It starts/dies, starts/dies, etc.  up to 10 or 12 times some times.  The instructions warn against using the preheat for more than 30 seconds, and that apparently is also running the fuel pump, so I dare not use it excessively.  Besides which, its 90 degrees here, preheat should hardly be needed.  Is this a known problem with a known cure?

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Re: Kubota generator hard starting

Reply #1 – July 06, 2010, 01:13:21 am

Unscrew glow plugs and check each for resistance, if none plug is shot.  We replace our glow plugs every 4 years or so or at first sign of hard starting, as they are cheap and easy change out.

It is ok to run preheat longer than 30 seconds.  Cold day may require over a minute.  Very cold days, several minutes.  Holding preheat turns on glow plugs and runs electric lift pump and cycles diesel from tank and back to tank, so extended running is not a problem.

Your symptom are the same as having bad glow plugs.  Multiple times of starting act as a pre heat as each engine short run heats cylinder more and more.

But 12 times seems a bit much, so you may have other problems.  And if it will not stay running, you may have a clogged air filter or an air leak in your fuel line.  Also there may be a little known inline fuel filter that sometimes never gets changed.  One test for a bad fuel line is to remove fuel line to lift pump. Install a temporary hose and stick the other end in a bucket of diesel fuel.  If it runs great, you have a fuel line problem.

Maybe you need  to run your generator more often and under a big load.

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Re: Kubota generator hard starting

Reply #2 – July 06, 2010, 10:42:49 am

Thanks, I've only had this a couple of weeks, but when I first got it, it would start after the 2nd or 3rd time, now up to 12 as I mentioned.  I'll check out your suggestions.  The hour meter quit working at 90 so I have no idea how many hours on it so I'll need to service it and check it all over.  Wondering out loud - why the heck aren't the glow plugs timed automatically, even my older than dirt Ford has that.

Gayland and Susan, but generally only Gayland
1996 U270

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Re: Kubota generator hard starting

Reply #3 – July 06, 2010, 06:44:16 pm

Most likely you are getting air into the fuel system through a cracked fuel delivery hose.  If you are, it takes a while to get the air out of the fuel system so that it will finally get enough fuel to keep running.  I have the same problem, only not as bad as yours, so I haven't gotten around to fixing it yet.  Others have fixed it and there is quite a bit of info on it in the archives.  From what I know, there is a 90 degree turn where the fuel line leaves the rear of the generator area and goes into the chassis and the fuel tank.

History indicates that most of the leaks have occurred in the 90 degree turn area.

Let us know how it goes.

I hope to get at mine in a week or two.

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Re: Kubota generator hard starting

Reply #4 – July 06, 2010, 09:52:42 pm

Sure well, but it'll be a few days before I get to it also.

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