Fast and Easy Fix for Your Generac Wheelhouse 5500 / 5550 Portable Generator

allthumbsdiy-generac-repair

WARNING
You should connect to your generator in approved methods ONLY, such as a generator interlock kit with NEMA L14-30 connectors via power inlet box or extension cords. DO NOT be tempted and connect your generator to one of your house outlets via a cord with 2 male-ends. This type of cord is also known as a “suicide cord” as this method will put you, your family and utility workers in harm’s way. You will be held liable for any property damage (fire) or death.

Please read this article for more information.

 
If you are like me, your generator has been sitting in your shed or garage for long periods of time and when you need it the most, your Generac Wheelhouse 5500 / 5550 portable generator does not start.

That’s what happened to me when Hurricane Sandy was approaching (October 28, 2012) and I could not start my generator.

I was fortunate enough to purchase a new Briggs and Stratton 5500 Storm Responder at the last minute (another story) and I would hate to think where my family (with 2 young children) would be if I had no generator during a (long term) power outage.

While my new generator was up and running, I spent some time posting some questions and researching my problem using Google. I was able to get my old generator to work with some simple fixes so I thought I would share that information in case you need it.

A special shout-out goes to DIYchatroom members Bondo, DexterII, oh’Mike, joecaption and Missouri Bound! (posting can be found here)

 

Repairing a generator means working with gasoline, gasoline vapor, various solvents, etc. Work in a well ventilated area, away from any sparks or heat and wear appropriate safety devices.

In addition, portable generators produce lots of carbon monoxide that is colorless, tasteless and does not smell. Follow the manufacturer’s instructions to keep it away from your house and make sure your carbon monoxide detectors are positioned near it

 

Types of Problems

Here are some of the symptoms I’ve experienced with stale gasoline.

  • Engine starts but quits running after 10-15 seconds
  • Engine does not start but gas leaks from the air filter
  • Engine will start only for few seconds with starter fluid
  • Engine will run rough under full choke but dies when choke is opened
  • Engine sputters, guzzles gas then dies

Causes

Did you know that gasoline goes stale after only 30 days (from the date of manufacture)? Couple that with some unscrupulous gas stations selling contaminated fuel, it’s no wonder some generators refuse to start.

Stale gas tends to create what looks like red rust which deposits on to internal components like the float, needle valve, emulsion tube, etc. Many of these components are small and have even smaller orifices which would easily be clogged, preventing your engine from running properly.

Obviously, there are other causes but the scope of this article is to get the Wheelhouse 5550 up and running by fixing problems caused by stale gasoline.

Game Plan

Since my generator has been sitting around for awhile, I decided to do some basic tuneup by replacing usual parts like air filter, spark plug, etc. This way, I was fairly confident that my problem was isolated to a carburetor build up.

Please note that Generac Wheelhouse 5500 / 5550 Briggs and Stratton engine may contain either Walbro or Nikki carburetor. Since my generator came with a Nikki carb, the article will only cover this particular carb.

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-carb-walbro-fl

Walbro Carb

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-nikki-carb-parts-fl

Nikki Carb

These diagrams can be found in page #4 of the Illustrated Parts List – Model 31c700 document.

Tools

Parts

Basic Tuneup FIRST

When I was in a hurry to get my generator up and running, I did not have the (time) luxury of troubleshooting each components. Rather, I did a quick replacement and tuneup using these components.

  • Replace the spark plug (gap set to .030)
  • Replace old with new fuel (premium or 93 octane preferred)
  • Add Sta-Bil (for gasoline) to new fuel and let is sit for 30 min
  • Replace Air Filter
  • Change oil (SAE30 during Fall/Winter or 5W-30 during Spring/Summer)

Step-by-Step Guide to Cleaning a Nikki Carburetor

Make sure to work in a well ventilated area. Place some sort of protective covering under the generator (I used a heavy duty trash bag) to protect the surface from fuel contamination and unless you like gas smelling hands all day long, wear a pair of Nitrile/latex/vinyl gloves.

Also, please note that pictures were taken during two separate times so some parts (like a fuel bowel) may not match the instructions. Please follow the instructions.

 

I attempted to clean the carburetor with it still attached to the engine but quickly found that I was not able to thoroughly clean it. In addition, the internal O-ring was virtually impossible to mount without the carb being upside down.

STEP 1 – Turn off the fuel supply valve (fig.1.1)
STEP 2 – Using a TBD” socket (try one of your mini ratchet sockets. I will update the size later), remove two bolts holding the air intake cover. Remove air filter (fig.1.1 and 1.2)
STEP 3 – Move the choke lever to CLOSED position. Make sure the handle notch is lined up with a small notch on the metal plate and gently pull up the handle (fig.1.3). DO NOT use excessive force. If it does not come up, double check to make sure notches are lined up.
STEP 4 – Using a TBD” socket (try one of your mini ratchet sockets. I will update the size later), remove two nuts holding down the metal air intake shroud. There is a rubber hose attached in the rear, upper left corner. Gently pry it off (fig.1.4 & fig. 2.1).

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-1-fl

fig.1.1

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-2-fl

fig.1.2

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-3-fl

fig.1.3

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-4-fl

fig.1.4

 
STEP 5 – Using a pair of pliers, squeeze the hose clamp to open (fig.2.1). Move it up so that the fuel hose can be removed from the fuel inlet (fig.2.2). Gently pry off the hose from the fuel inlet (expect some gasoline to drip out)
STEP 6 – Using a TBD” socket (try one of your mini ratchet sockets. I will update the size later), remove 2 bolts holding down the carb to engine (fig.2.3). These bolts are SOFT BRASS. DO NOT use pliers to try to remove these bolts as you will crush the ends.
STEP 7 – While holding the detached carb in one hand, slightly rotate it to gently unhook the governor spring wire (thin) and a throttle linkage cable (thick) (fig.2.4).

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-5-remove-fuel-hose-fl

fig.2.1

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-5-remove-fuel-hose-2-fl

fig.2.2

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-7-remove-carb-fl

fig.2.3

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-8-remove-governor-throttle-fl

fig.2.4

STEP 8 – Using a flat (slot) head screwdriver, remove two screws and washers that are holding down the carb fuel bowel (fig.3.1). Be careful as it will hold about 2 oz of gasoline. Also, there will be a loose spring inside (fig.3.3). This is what keeps the internal plastic components (float, gasket-float bowel) in place. Make sure to keep it in a safe place. Note how in fig.3.2, you see reddish deposit on the bottom with some flakes. These are deposits from a stale gasoline. Use a small amount of carb cleaner to clean them as much as possible.

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-12-carb-fuel-bowel-fl

fig.3.1

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-10-dirty-fuel-bowel-fl

fig.3.2

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-11-dirty-fuel-bowel-spring-fl

fig.3.3

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-9-remove-float-fl

fig.3.4

STEP 9 – A large plastic piece that is now visible is called a float (fig.3.4). Carefully slide out the hinge pin using a straight paper clip. One end of the hinge pin is crimped so it can only slide out in one direction so if you cannot easily slide it out, try pushing it in the other direction.

Once the float is detached, you will see a small gray “needle valve pin” (fig.3.5, fig.3.6 and fig.3.7). This needle pin either opens or shuts the fuel valve so that tip needs to be free of any debris. Be careful as the tip is made of rubber and it will pop off easily (and very easy to lose!). Using some fresh gasoline mixed with carb cleaner (2:1 ratio), clean off all gunk (as stated previously I do not like using straight solvent on plastic pieces as it may degrade the plastic components) so what I did was to dip some cotton swabs in the mixture clean off the gunk. Fig.3.8 is the end result of that cleaning which took about 20 minutes.

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-13-float-needle-valve-clean-fl

fig.3.5

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-14-remove-needle-valve-fl

fig.3.6

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-15-clean-needle-valve-tip-fl

fig.3.7

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-16-clean-float-needle-fl

fig.3.8

STEP 10 – The remaining round plastic piece (gasket-float bowel) channels the gasoline flow. Note how the inlet and outlet ports are clogged with junk (fig.4.1 and fig 4.2).
STEP 11 – The inlet also has a small (ceramic) piece with an O-ring that gets open/shut by a needle valve (fig.4.2 and fig.4.3). Gently pop it out by using a Q-tip with firm force. DO NOT use an awl or any sharp, pointed objects which can enlarge the hole or worse, crack it.
STEP 12 – Using a thin wire, clean off as much gunk as you can, not just the hole but all surrounding area (fig.4.4) If there is gunk left, needle valve cannot seat properly which will flood the engine (which is what happened after my first clean attempt).

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-17-fuel-plate-fl

fig.4.1

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-17-fuel-plate-side-2-fl

fig.4.2

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-20-fuel-inlet-flow-control-fl

fig.4.3

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-21-fuel-inlet-flow-control-2-fl

fig.4.4

STEP 13 – This is what it looks like after thorough cleaning (fig.5.1 and fig.5.2).
STEP 14 – To pop the ceramic flow control piece back in, I used a small piece of leftover 12 AWG electrical wire. You can also use a Q-tip, but make sure you hear the “click” to ensure that the O-ring has been seated properly.
STEP 15 – On to cleaning the carburetor itself. VERY Carefully remove the O-ring seal and put it aside (Fig.5.3; BTW, if you are attempting to clean your carb that is still attached to the engine, it will be fairly impossible for you to re-mount this O-ring so you may *not* want to remove the O-ring).
STEP 16 – Using a carb cleaner, carefully and thoroughly clean all holes and grooves (I also used Q-tip to scrub the gunk off). Pay special attention to the inlet port where fuel enters the carburetor chamber. I ended up using Q-tips soaked with straight carb cleaner (no plastic inside the carburetor) to clean the inside, making sure to not leave behind any Q-tip remains.

Carb cleaner can unexpectedly shoot out in different directions or even deflect back at you. Make sure to WEAR EYE PROTECTION and preferably a long sleeved shirt

 

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-20b-fuel-inlet-flow-cleaning-fl

fig.5.1

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-22-fuel-inlet-plate-cleaned-fl

fig.5.2

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-23-cleaning-nikki-carb-fl

fig.5.3

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-24-cleaning-nikki-carb-2-fl

fig.5.4

STEP 17 – Now that all parts have been thoroughly cleaned, it is now time to reassemble the carburetor and re-attach it to the engine. Just use reverse steps to reinstall, making sure to install the retainer spring before seating the fuel bowel (fig.6.1 through 6.8).

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-30-reassembly-fl

fig.6.1

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-31-reassembly-fl

fig.6.2

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-32-reassembly-fl

fig.6.3

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-33-reassembly-fl

fig.6.4

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-34-reassembly-fl

fig.6.5

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-35-reassembly-fl

fig.6.6

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-36-reassembly-fl

fig.6.7

allthumbsdiy-images-generac-wheelhouse-5500-5550-gen-repair-37-reassembly-fl

fig.6.8

Once you are done, turn on the generator switch (marked as “ON” or “I”), open the fuel supply valve, set to full choke and pull to start. Hopefully that will get it to start up right away! My older generator actually sounds like it runs much better than my new Briggs and Stratton generator!

Well, that’s all there is to it. If you are unclear about my instructions, please feel free to post your question in the comment section. While at it, if you found this article to be useful, please sign up for my newsletter.

Thanks and good luck!

SOURCES / REFERENCES

 

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    Comments

    1. John says

      This article is great.

      I had my generator that sat in my shed for 5 years without being used. of course when I needed it, it did not start (no surprise there).

      I was able to follow your directions and cleaned the heck out of my carb parts to get my generator to start.

      In spring, I plan on following rest of your directions to do a complete tuneup.

      thanks again

      john

    2. Brett says

      I just bought a gently used generac wheelhouse 5500 just like the one you have pictured and i would like to find out the date the engine was built and any other engine info so i can get replacement parts for it if i ever need to but i cant find the date code anywhere on it and all i can find is model number and other info on a sticker on the grey shield next to the muffler, can anyone please help me find the date code on the engine?

      Thanks

    3. kevin says

      @Brett

      I believe engine date codes are stamped on the alternator housing but it needs to be de-coded.

      Have you called the Generac customer service toll-free number at 1.800.270.1408? I am sure they can look it up using your serial number.

      Also, if the unit has not been used for awhile, you should drain the old gas and replace it with new gas, and disassemble and clean the carb.

      Let me know if you need help

      Kevin

    4. Brett says

      Thank you,i found it, it is under the chrome ohv cover and i already drained the gas and changed the oil to a full synthetic 10-30 motor oil and i would clean the carb but i need to read up some more on what carb i have plus i need to get the courage to tear into it.

      Thamk you for the fast response and great website.

    5. kevin says

      nice. wheelhouse 5550 is a sturdy, reliable genny. with a little maintenance, it should last a very long time.

      at the end of my article, there should be some links to pdf files that should help with your rebuild.

      good luck with your new generator!

    6. jeff says

      How much oil typically goes in the wheelhouse 5500? and what type of oil is best?

    7. kevin says

      @jeff-

      That is an excellent question and I never found an answer for it. If you are using 5550 Wheelhouse, it has a traditional dipstick so I used to put in little bit of time until the stick indicated the oil was at a proper level.

      For the 5500 (the newer version I currently own), it did away with a dipstick in lieu of a plug. What I did was to fill up with new oil just below the threaded hole (that was the factory oil level). Can’t remember the exact quantity but I think it was about half quart.

      As far as the oil viscosity is concerned, I would use SAE30 during Spring, Summer and Fall. During the winter, change it over to 10w30. Of course, if you have cash to burn, you can put in the synthetic 5w30 that can be used all year around.

      Just make sure to fire up your generator every month with some load on it and run for 30 min. or so. With storm season already in route, you don’t want to be caught shorthanded like I did last year.

    8. Lisa says

      I am trying to change the choke handle cord on my power boss 5500 generator and cannot get the cover off to replace it. I bought the new cord and need to get the facing off of the generator. It has star shaped alley key screws (they are stripped) and they will not come off. What can I do to get the screws out to fix my generator ? Please help ASAP!

    9. kevin says

      @Lisa-

      Hi there-

      I think all DIYers have experienced stripped screw heads at least once.

      Fear not, they make nifty extractors for this purpose! I highly suggest Alden 8440P Pro Grabit Broken Bolt and Damaged Screw Extractor 4 Piece Kit due to its metal strength and durability.

      Please, please avoid any 5 dollar sets from Harbor Freight as they will cause more headaches!

      Good luck and please let us know how you made out.

      Kevin

    10. kevin says

      @bernard-

      thanks! make sure the generator is in top shape (and have gas on standby) with this crazy winter!

    11. john says

      That all good but there are many articles on working with Briggs engines but none address actual generator side charging and electric output etc.??

    12. kevin says

      @John-

      Most of the articles are based on things that need to be repaired as I experience them. I’ve been lucky in that I have not experienced any electrical output issues. Are you having trouble with yours?

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