Onan generator stops after a few minutes

The friendliest place on the web for anyone with an RV or an interest in RVing!
If you have answers, please help by responding to the unanswered posts.
See posts with no answers
You are going to have to remove and take the carb apart to clean it or buy a new one. Take it apart and clean it, what have you got to lose? You need a can of carb cleaner and compressed air to clean out the small passages. You can get the carb cleaner at any parts store or Walmart.  I use Walmart brand .
 
92GA said:
You are going to have to remove and take the carb apart to clean it or buy a new one. Take it apart and clean it, what have you got to lose? You need a can of carb cleaner and compressed air to clean out the small passages. You can get the carb cleaner at any parts store or Walmart.  I use Walmart brand .
Click to expand...
Yep...nothing to lose at this point.  I have plenty of carb and choke cleaner and a good air compressor.  Guess I should order a gasket kit...
 
Been a while since we had my buddies apart. Some have a fuel solenoid on the bottom of the bowl area. That should screw out. The bowl should have an O ring seal, and if careful it should seal up again. Search the net for a service manual from flightsystems. I down loaded their manual when we were working on my buddies 7000.

I just checked my manual. if your carb doesn't have the solenoid, the MAIN ADJUSTMENT
SCREW ASSEMBLY, will come out as a unit. It holds the bowl on. The main adjustment is from lightly seated 2 turns out + or - 1/4 turn.

It may also have just a nut on the bottom holding on the bowl. Shows a few different carbs.
 
Mine is essentially the same as the photo I've attached here except that the bowl is black and so is the "altitude adjustment knob" on the bottom.  That knob appears to be held in place with some sort of brass fitting that's smooth and recessed into the plastic knob.  The link I shared a few posts ago is the only "exploded view" I've been able to find and it wasn't very helpful.  I'll search over at Flight Systems.  Thanks!
 

Attachments

  • 146-0455.jpg
    146-0455.jpg
    19.9 KB · Views: 29
That carb is the same one they used with the main adjustment on the bottom. The altitude adjustment, adjusts the main jet. The brass piece is what's holding the bowl on. That should screw off counter clockwise looking at it from the bottom.
 
92GA said:
That carb is the same one they used with the main adjustment on the bottom. The altitude adjustment, adjusts the main jet. The brass piece is what's holding the bowl on. That should screw off counter clockwise looking at it from the bottom.
Click to expand...

The plastic "knob" only allows the brass fitting to turn 90 degrees.  Not sure how to get it out of the way.  Terrified of breaking it if I pry on it.  Photos attached...  Thanks for your input!

By the way, this is a 146-0630.
 

Attachments

  • IMAG0706.jpg
    IMAG0706.jpg
    153.5 KB · Views: 24
  • IMAG0705.jpg
    IMAG0705.jpg
    143.5 KB · Views: 23
OK, I pried the thing off and counted 8.25 turns to get the needle valve out.  If I blow into the hole (yes, with my mouth, I'm that desperate...but don't get any ideas) air passes through to the throttle body.  However, if I blow into the fuel inlet...well, I can't.  I can't make air go through it.  I just love the taste of gasoline in the evening.  ;)  Shouldn't I be able to blow air into the fuel inlet hole and have it pass through to the bowl somewhere?  I've tried right-side-up and up-side-down (to change the float position) with no luck.  Is that just proof of blockage, or merely proof that I'm a moron?
 
did you try and rotate the bowl itself counterclockwise see if it unscrews? and yes inside the bowl your float and needle are probably gummed up. you should be able to blow thru the fuel inlet only holding the carb right side up and not while upside down.
 
Sam! said:
did you try and rotate the bowl itself counterclockwise see if it unscrews? and yes inside the bowl your float and needle are probably gummed up. you should be able to blow thru the fuel inlet only holding the carb right side up and not while upside down.
Click to expand...
Hi Sam!  If the bowl unscrews, it does so with more torque than I can muster with bare hands and rags.  Not sure what tool would help in that regard.  I definitely cannot blow air through the fuel inlet while the carb is right-side-up, nor does fluid (in this case, Sea Foam) drain from the inlet into the carb/bowl.  I have a 90 degree brass fitting in the inlet with the entrance upward so that I an pour cleaner into it and see if it drains, and it's doesn't...  Not yet, anyway.  Needle valve screw is still out.  Thoughts?
 
Shown here is the brass fitting filled with Sea Foam going nowhere...
 

Attachments

  • IMAG0711.jpg
    IMAG0711.jpg
    181.5 KB · Views: 24
put some compressed air in that. (without the fluid)

can i see a new picture of the bottom again with out the altitude needle?

 
Hey Sam.  I put compressed air in the inlet yesterday (120psi air hose) without fluid.  I'll try again today.  Here's a photo of the bottom of the carb with needle valve removed.
 

Attachments

  • IMAG0713.jpg
    IMAG0713.jpg
    118.5 KB · Views: 22
there you go take that brass fitting off, that hold the bowl pressed up against the carb. that will expose the float needle and seat and main jet.
 
The bowl came right off in my hand, gasket intact.  And wow, you could grow plants in all the crud that's in here!  And it doesn't just look like dirt but rather some kind of sealant debris, like someone tried to use pipe sealer where the fittings came together.

The float doesn't "float" (move up and down) very easily, but I can't see why.  I removed it and pulled the needle valve from the fuel inlet hole and it had a chunk of crud in it, too, hence the cause of fuel starvation.

I'm going to hit this thing with some more Sea Foam then dry it all off with my air compressor, put it back together, and hopefully have a working generator today.  :)  I'll post more photos shortly.
 
Use regular carb cleaner spray and compressed air. There are very small passages, they all have to be cleaned. Spray backwards through the seat and then blow it with air.

Make sure the float moves freely before you put it back together. Turn the carb upside down ant right side up the float should move freely when doing this.
 
92GA said:
Use regular carb cleaner spray and compressed air. There are very small passages, they all have to be cleaned. Spray backwards through the seat and then blow it with air.
Make sure the float moves freely before you put it back together. Turn the carb upside down ant right side up the float should move freely when doing this.
Click to expand...

All inlets have been sprayed with carb cleaner and compressed air.  No particulate matter remains.  The needle valve that rides the float moves very freely in its chamber.  However, the float pivot seems to bind and I'm not sure why.  There's a strange, bent screw holding the pivot rod (photo attached).  This screw was pretty tight when I got into the carb, and I could only turn it about 90-120 degrees before it would bind up on the float since it's bent.  There's a dot in the head of the screw that corresponds with the direction of the bend.  The pivot rod is very easy to slide into and out of the float, so you would think that the float would pivot on it without having to turn the rod.  But as soon as this bent screw is secured against the rod, the float does not easily move.

Note that these photos were taken before the thorough cleaning activities, and they were taken randomly for the most part so they aren't necessarily the best views.
 

Attachments

  • IMAG0730.jpg
    IMAG0730.jpg
    145.8 KB · Views: 21
  • IMAG0738.jpg
    IMAG0738.jpg
    139.1 KB · Views: 19
  • IMAG0722.jpg
    IMAG0722.jpg
    166.7 KB · Views: 17
You must log in or register to reply here.

Latest posts

Members online

Total: 734 (members: 18, guests: 716)

Forum statistics

Threads
131,964
Posts
1,388,305
Members
137,716
Latest member
chewys79
Back
Top Bottom