Generator tune-up. I Learned to do it myself today!

[Mr. T]

My 4000 Onan generator needed a tune up.  She searched all the time and wouldn't run my 1100 watt microwave I recently installed.  I found out what having a professional shop would cost.  I decided to spend the money on a good set of electrical tools to do the job myself.  With a little practice, I got the generator to specs, no load and with load.  It will run the microwave, but it puts a heavy draw on the generator.  I did find that powering down the microwave to around 7 or 8 allowed the generator and microwave to work in harmony.

I would recommend anyone with a generator to buy the tools to do your own work. It is not hard.  Fun to watch the frequency and volts change as you make adjustments.


Don T.

[ibdilbert01]

Nice work!


Might need to do some more tuning.   A properly running 4000 watt generator will run a 1100 watt microwave with not much trouble other than a burp when the magnetron kicks in.   

[Stripe]

Nice job and I bet it kicks in more Pride in Ownership as well..

[M & J]

Groovy!

[Mr. T]

Tim, thanks for your comments.  You are probably right, but I am thinking the wiring from the electric box to the microwave is too small.  Here is my reasoning:  I replaced a small wattage microwave with this new and larger one.  This microwave works just fine on any power other than high.  Start it out on high and the microwave shuts itself down, like it has it's own trip switch inside.

The generator seems to be doing its job.  Not searching, bouncing around the frequency of 62 to 63.  Volts to the house wiring at 123 to 127.

Any other thoughts you might have would be most appreciated.

Don T.

[RV Mech Tech]

MR T - congrats on doing your own tune-up and work on the Onan 4000 - the dealers charge quite a bit to do this - one thing to keep in mind is that in an air cooled engine  oil takes on more of the cooling than in a liquid cooled engine and the fact that the 4000 does not have an oil filter puts oil changes as a high priority along with a tune up - also one of the other things I do when servicing any generator is to clean out any debris in and around the motor and generator as much as you can get at - you can use compressed air and a long nozzle blower to get in and around anywhere you can insert it - you will be surprised at how much garbage comes out of there so make sure you wear eye protection while doing this - the 4000 as with many other single cylinder generators has the engine and generator attached together - air flows over the engine first and then through the generator  and a lot of stuff gets pulled in with the air so keeping these areas clean goes a long way to prolong the life of the generator - also air cooled generators will have a cooling air intake inlet and exhaust outlet  and  both of those are on the bottom of the 4000 as well as the larger twin cylinder RV Onans  (55. 65, and 7500 watt units as well as other generator makes ) and in some cases the generator sits close to the ground so its easy for items like plastic bags to get pulled into the intake and block off the cooling air so check for any obstructions - ( your 4000 has the intake on the bottom and the exhaust goes around the muffler and then down to the ground ) - and of course when putting your RV away for storage make sure you put in fuel stabilizer and run the generator for at least 15 minutes (in most cases ) to make sure the stabilizer gets into the carb to prevent gum formation inside the carburetor and ruining it - you need a Swiss bank account to replace  those Onan carbs for the newer generators   - moisture can and does get into the generator section  when sitting over the winter so starting up and running the generator for at least half an hour once a month  ( one hour is preferable ) to exercise the generator and dry out any moisture that may have collected inside will prevent any damage  - I have had to replace more than one stator ( Internal wiring coils ) in generators because they were badly rusted from sitting  - I hope this gives members some insight to generator maintenance and encourages owners to do their own service - as Mr T says -  " It's not hard "       

[Mr. T]

IBDILBERT01 (Tim),


You were right.  I took the carb off and gave it a good cleaning.  Microwave hums like a champ.


Don

[M & J]

Your microwave has a carb? Must be really old.....

[Mr. T]

I used to heat my hot dogs on the car radiator.  A carburatored microwave is just an extension of that.  I plan to sell it to someone who lives in Washington State to be used for space travel.  :)rotflmao


Don

[DonD]

Just gave my 4000 a oil change and new filter....1200 hours and still charging

[Stripe]

I used to heat my hot dogs on the car radiator.  A carburatored microwave is just an extension of that.  I plan to sell it to someone who lives in Washington State to be used for space travel.  :)rotflmao

I have no idea who he's talking about..  Nope, none...