 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Car Forum / Driving, Maintenance, Tuning / RVs / August 2005Generator question
Onan gas genset troubles... I have an Onan Microlite 4000 in my RV. The generator has been working fine until about 2 weeks ago. When operating the genset for any length of time, (like 10-15 minutes or more for the genset to warm up,) after shutting down, the genset will NOT start again until it cools off. I have replaced the air filter, the spark plug and re-gap'd it to spec. Unplugged the ignition module, cleaned the plugs, replaced the small hose from the exhaust to the choke control (the small aluminum 1.3" bendable hose to the right when you look in)... I have a new fuel filter, have not put it in, but I do not think that is an issue, since the genset starts fine when it cools off. The low pressure pump overheating? when cranking the genset when it is hot (when it won't start) it kicks once over after releasing the start switch (either remotely or with cover off) I thought of vapor lock, but can't see that appearing from two weeks ago. I do not want to burn the starter out again (and yes - it the starter has overheated again and I will probably replace it again in the next month - what a pain) it was replaced by me a couple years ago, the wife cranked the genset with the gas tank about 1/4 full. Ideas? Thanks in advance. Ed (I want a diesel George- do not like this) it is my understanding that the gen (onan 4000) will not run if there is no juice is being produced. cj > Onan gas genset troubles... > [quoted text clipped - 30 lines] > > (I want a diesel George- do not like this) There is "juice" being produced. It generates current just fine. The air and the microwave will run until the gas runs out. I had the air running for 3 hours today while I was working in it at the end of the driveway. > it is my understanding that the gen (onan 4000) will not run if there is > no juice is being produced. > cj > >> Onan gas genset troubles... > Onan gas genset troubles... > [quoted text clipped - 30 lines] > > (I want a diesel George- do not like this) Try starting with the gas cap off. Newt > Onan gas genset troubles... > [quoted text clipped - 28 lines] > > Ed Ed, I hate to say it - because it's such a huge pain to get to and change - but it appears that the electronic magneto is failing due to heat soak. The clue is that you get -one- spark when you release the start switch and the control grounds the magneto coil. For quick confirmation, set your meter to ac volts, hook one lead to ground, and the other to the small terminal on the coil (without disconnecting the lead from the terminal). When running normally, you should see (IIRC) about 16v ac. After you've run it for a while and shut down, then check the voltage again. If you see very low/no voltage, with a short spike when you release the start switch - the magneto is failing when hot. (I'll have to check the books Monday - it may have been 16v ac at the lead when disconnected from the terminal - but I've worked on two with no spark except when the start switch was released, and both times it was the magneto. Given the way it works, not much else could cause those symptoms). Alan Hi Alan- Well that sounds just great. More work. Oh well, I was planning to replace the starter anyway. It works, but it smells toasty when cranked for 2 cycles of 10 secs each. So, the genset will be off the RV anyway. I was also thinking of adjusting the valves at the same time. I will replace the fuel filter at the same time. An early afternoon of work. What you describe is exactly what is happening. A neighbor is a mechanical engineer for Cummins/Onan here in Minneapolis but I think he works on the design of diesel generators and such. Unfortunately (for me), he is out on holiday this week, and I am taking off for a fundraising bike ride this afternoon that will last until Friday. He always comes up with a solution- he asks people up at at Onan. Oh well. I have already advised the boss (wife) on how to use the genset with this condition - wait until it cools a few hours if it does not start after using, or just leave the thing on all day if necessary to run the air. it is going to be hot and humid. I am going to check the newsgroup at night if I can from the road. Thanks for the ideas Ed >> Onan gas genset troubles... > Ed, [quoted text clipped - 15 lines] > > Alan Hi Alan Ok- Back from up north and successful bicycle ride. The generator acted up for the first couple of days. Now after running the bugger for 3 days, I return home, run the genset for 2-3 hours while wife and I clean it, (with A/C running) shut down A/C and let genset run for 5-10 minutes to allow cool down of genset, stop genset and waited for a few minutes. Tried the starter again, genset runs fine. ????? Thanks Ed >> Onan gas genset troubles... >> [quoted text clipped - 47 lines] > > Alan > Hi Alan > [quoted text clipped - 14 lines] > > Ed Aren't intermittent problems SUCH fun? As I said, your original symptoms point to the magneto - so I would advise you to read the voltage you see from the magneto at the coil (the small terminal), so you'll have a reference point when/if it happens again. Based on my experience, an intermittent only goes away long enough to lull you into thinking everything's ok - then reappears at the most inconvenient possible time <g>. Or - maybe the war dance with large hammer in hand got its attention? Alan |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.