I have an 8000 watt, or is that volts, generator that I have had for
over 10 years. It has a 16 HP Briggs & Stratton engine.
I was getting it ready for winter by changing the oil and filter and
found that the fuel pump had a leak. I had the gas turned off at the
gas tank and didn't know about the leak until I turned the gas on.
Glad I found that before I needed the generator in the middle of
There are two holes in the pump body but they never leaked before. I
took the old pump with me when I went to the dealer to get a new one.
The service guy said that there must be a diaphragm in there that
eventually shrinks and allows gas to get to those holes.
This generator has a fuel shutoff between the fuel tank and the fuel
pump. As long as I've had this thing I have shut the generator down by
turning off the fuel supply so the fuel pump and carburetor run dry of
fuel and shuts down and then I put it in the garage for storage until
I need it again.
I figure since the generator sits in storage for long periods if I run
all the gas out of the carburetor then it is not as likely to gum up
versus leaving the fuel pump and carburetor full of fuel to eventually
So is my thinking about that right? Or does it really matter at all?
Your thinking is correct but the real question you should be asking is
why doesnt the diaphragm or similar rubber part in your car or truck
shrink. Just because something is made of rubber doesnt mean that it
can stand up to gasoline without deteriorating. The chemical
composition of all rubber is not the same. So the diaphragm should not
have shrunk in the first place and who is responsible if it did?
This one has three lines. One from the fuel tank, one to the carb and
one to the crank case. Since there are no electrical hookups, I assume
it is vacuum driven.
This engine is amazing. I had not started it in months and after I got
the oil changed and put on the new fuel pump, I found that the battery
was dead and needed to be replaced.
I had never tried starting this engine by just using the pull start so
I thought I would give it a try. One pull on that thing and it started
right up. And it pulled so easy. Wow!!
On Thu, 04 Nov 2010 15:18:07 -0700, Country wrote:
No need to be vacuum driven. It has a emission control system that feeds
crankcase vapors back into the intake.
Compression release. The Kohler Commander motor in my John Deere tractor
has one. The 6.5 horse on my leaf vac/shredder/chipper has one. The motor
on my John Deere 59cc chain saw has one. The saw is almost impossible to
pull if you don't push the compression release before trying to start it.
Hope you got all your issues answered. I've owned a 5kw Brigs powered
generator for 15 years. Used it once in 2002 when a tornado took out a
substation nearby. Took 3 days to restore the power. This generator
Generac isn't the most fuel efficient. Consumes about 1.5 quarts per
I just shut off the generator and then close the fuel valve. Could it be
the diaphragm/gaskets dried out?
Since power failures are quite common in my rural area (power lines
running through roadside tree branches), I run the generator on occasion
just to get things moving before I really need it.
I think it is more of what is called long term storage. If this is going to
be 6 months or longer then you may want to drain the gas and run the motor
long enough to starve it of gas. That is similar to what most manuals say.
Also pull the spark plug and add oil to the cylinder and replace the plug.
If less then I would just start it about every 2 weeks and let it run for
about 10 minuets.
I bought a new 5 kw generator about 10 years ago and opened the box to see
what it needed to get it going. closed up the box for a year. Put in the
oil and gas and it started up. Ran it for a couple of hours when the power
went out. Drained the gas and about a year later it started fine when I
needed it. This time I did not drain the gas and had other things going on
so it just sit. Would not start about a year later . Carburetor gummed up.
Cleaned it out and all was fine. That happened twice. Now I put in the
Sta-bil in the gas and start it up atleast every 3 weeks. It will usually
start with 2 or 3 pulls just as it always did when new. I think it is even
more important not to let the gas sit too long with out the Sta-bil as it
has that junk called ethanol in it. Or however you spell it.
If you have a diaphragm? and a pump? Sounds more like a stuck needle
valve overflowing the carb bowl. Running it out of gas does not mean the
carb is empty. Some gunk still forms in there.
It would be better to change the fuel in the tank once a year and run it
for 15 minutes to get fresh gas through it. Use the old gas in your
lawnmower or garden tractor.
Simple job, assist the assistant of the physicist.
Many of the responses seem to believe that the fuel tank is above the
carburetor and that there is no actual fuel pump, just some sort of a
regulator for the fuel leel in the carburetor. There scould be a
pumping action based on the alternate pulsing of the crankcase
ventilator if a pump were needed. Can the OP please state where the
gas tank is located with respect to the carburetor.
The fuel tank is above the engine on this unit. The part that I
replaced is called a fuel pump. How much actual "pumping" it does, I
do not know.
It was a pretty easy fix replacing the pump. It cost just under $30
for the part.
I have a 7500w generac, that 3rd line is probably to recycle gas
vapors into the crankcase, my tank is on top, with a tank on top you
dont need a pump, thats why they are on top. That leak must be the
carb, check your oil level, Ive seen Generac float valves stick and
completely flood the motor with gas, but even a bit ruins the oil so
be carefull if its flooded, it can thin the oil so you motor is ruined
from lack of lubrication with thined oil.
My friends generac was so flooded it wouldnt pull, when we took out
the plug and pulled the rope gasolene shot out 10 ft. And it flooded
like that overnight from a stuck float valve not closing, Thats why
shutting off the gas after every use is important. Check if you have a
fuel filter, my 7500 xl didnt come with one, which it dumb, it has
everything else and the crap from the bottom of the tank goes right to
the carb and screws up the small jets and openings.
Thanks for trying to help but I already had that problem fixed when I
posted the OP. There is fuel pump on this thing and it was leaking
which is why I replaced it. My reason for the OP was to inquire about
whether to continue shutting off the fuel supply and running the
carburetor dry of fuel when I go to shut the generator off after
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