Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 12-06-2017, 03:48   #1
Registered User

Join Date: Nov 2009
Location: Dartmouth and Bristol, England
Boat: Northwind 50 - 50ft - Camille
Posts: 40
Generator failure

I have an Onan MDKAV 7.5kw 50hz which has served well over 14 years with relatively low usage (est. 2,500 hrs) and it now does not start. I know about Onan coding but the signal I get is green and yellow flashing together repeatedly - no coding. The problem began occasionally with the motor running well when it did start but now nothing at all. Can anyone help please?
Camille1 is offline   Reply With Quote
Old 12-06-2017, 05:03   #2
Registered User
 
ranger58sb's Avatar

Join Date: Aug 2012
Location: Maryland, USA
Boat: 58' Sedan Bridge
Posts: 5,420
Re: Generator failure

I can't interpret your question, yet. Do you mean only the generator has failed? Or do you mean the (diesel?) engine won't start/run? Or...?

-Chris
__________________
Chesapeake Bay, USA.
ranger58sb is offline   Reply With Quote
Old 12-06-2017, 05:07   #3
Registered User
 
Sailmonkey's Avatar

Join Date: Sep 2009
Location: Houston
Boat: ‘01 Catana 401
Posts: 9,626
Re: Generator failure

And if the engine doesn't run, does it at least crank?
Sailmonkey is offline   Reply With Quote
Old 12-06-2017, 06:01   #4
Registered User
 
svHyLyte's Avatar

Join Date: Mar 2006
Location: Tampa Bay area, USA
Boat: Beneteau First 42
Posts: 3,961
Images: 25
Re: Generator failure

If it is the drive motor, when was the last time the valve clearances were set? You might find that re-setting the valves to the proper clearances solves the problem.

FWIW...
__________________
"It is not so much for its beauty that the Sea makes a claim upon men's hearts, as for that subtle something, that quality of air, that emanation from the waves, that so wonderfully renews a weary spirit."
svHyLyte is offline   Reply With Quote
Old 12-06-2017, 06:17   #5
Registered User

Join Date: Nov 2009
Location: Dartmouth and Bristol, England
Boat: Northwind 50 - 50ft - Camille
Posts: 40
Re: Generator failure

Thanks for your responses. I should have said clearly that the problem related only to the generator and the 'motor running well when it did start' meant the generator motor (which is Kubota 3 cy diesel) and not the boat drive engine. No attempt at cranking now - when it did crank (before complete failure), it always started immediately - always has. The primer (lower part of switch) works the fuel pump or sounds as if it does. (New fuel pump 20 hours ago.)
Camille1 is offline   Reply With Quote
Old 12-06-2017, 07:15   #6
Registered User
 
ranger58sb's Avatar

Join Date: Aug 2012
Location: Maryland, USA
Boat: 58' Sedan Bridge
Posts: 5,420
Re: Generator failure

So it's the generator motor that's the problem, and it now doesn't start, yes?

Often fuel or air, but first... do you have electrical power to the starter? Click? Or nothing? Could be something as simple as a loose electrical, perhaps ground, connection.

I'd say check and report on that first before everyone has to go down the fuel or air rabbit holes...

-Chris
__________________
Chesapeake Bay, USA.
ranger58sb is offline   Reply With Quote
Old 12-06-2017, 08:27   #7
Registered User
 
Sailmonkey's Avatar

Join Date: Sep 2009
Location: Houston
Boat: ‘01 Catana 401
Posts: 9,626
Re: Generator failure

If the preheat function works, my bet is on the signal wire to the starter solenoid coming loose.
Sailmonkey is offline   Reply With Quote
Old 12-06-2017, 23:18   #8
Registered User

Join Date: Feb 2015
Posts: 1,225
Images: 1
Re: Generator failure

I'm really not following your description of the symptoms.

Does it not crank at all? And if it doesn't crank, does it make any sounds when you attempt to crank it?

Or does it crank but not start running?

BTW, be careful about over cranking and flooding the muffler and subsequently the engine. Then you will have a big problem.
__________________
www.MVTanglewood.com
tanglewood is offline   Reply With Quote
Old 13-06-2017, 00:03   #9
Registered User

Join Date: Nov 2013
Location: Slidell, La.
Boat: Morgan Classic 33
Posts: 2,845
Re: Generator failure

Know nothing specific about your genset, but the gradual onset of the problem suggests an electrical connection problem, more likely a corrosion-related ground issue than a positive side one, a mal- or non-functioning sensor issue, or a computer (chip/pc board) gremlin.


Start with the easiest/cheapest first (checking/verifying connections), move to process of elimination on sensors, senders and switches, and unless you're an electronics person, call in a technician for computer issues beyond simple replacement...


Perhaps someone with info specific to your genset will pop up though...
jimbunyard is offline   Reply With Quote
Old 13-06-2017, 01:10   #10
Registered User

Join Date: Nov 2009
Location: Dartmouth and Bristol, England
Boat: Northwind 50 - 50ft - Camille
Posts: 40
Re: Generator failure

Thanks, Tanglewood. The generator now does not try to start at all. the problem grew over two weeks. first it was occasional not trying to start but increasingly frequently it did not try until now when it does not try at all. I think Jimbunyard may well be right that it is an electrical connection problem, possibly corrosion related - maybe the connection to the starter solenoid as Sailmronkey suggests. I have gone around the sensors but they are either new or test OK. Thank you all for the useful guidance; i just hope it is not the control panel !
Camille1 is offline   Reply With Quote
Old 13-06-2017, 04:54   #11
Registered User
 
Captain Bill's Avatar

Join Date: Apr 2008
Location: Punta Gorda, Fl
Boat: Endeavourcat Sailcat 44
Posts: 3,173
Re: Generator failure

If the engine started and ran as long as you held down the start switch then stopped when you let it up it's possible your brushes are bad. My mdkau 5kw did this when my brushes went bad at about 2450 hours. The computer shuts down the engine if it doesn't see 120V on mine and probably 240v on yours which it can't generate if the brushes are bad. Excessive cranking may have compounded the problem by causing a hydrolock.
Captain Bill is offline   Reply With Quote
Reply

Tags
generator

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Portable Inverter Generator or Reg. Generator? Hatch Liveaboard's Forum 54 15-06-2017 23:05
Generator vs Inverter Generator (Genset) Jon4399 Electrical: Batteries, Generators & Solar 30 11-01-2011 09:13
Portable Generator vs Solar Panels or Wind Generator Sweet As Electrical: Batteries, Generators & Solar 120 16-09-2010 18:27
Any way to convert a DC Generator to an AC Generator? Latitude9.5 Engines and Propulsion Systems 13 06-04-2007 11:06

Advertise Here


All times are GMT -7. The time now is 11:44.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.