Small Engine

Small Engine Troubleshooting Problems? Ask a Mechanic Now.

Ask an Expert,
Get an Answer ASAP!

Hurricane Irma is closing in, and my Generac Ultra Source…

Customer Question
Hurricane Irma is closing...

Hurricane Irma is closing in, and my Generac Ultra Source 15000 will not stay running

Mechanic's Assistant: I'll do all I can to help. How long have you been dealing with this?

2 days

Mechanic's Assistant: Do you plan on doing the work yourself?

No service is available due to the hurricane commin

Mechanic's Assistant: Anything else we should know to help you best?

Wa

Submitted: 11 months ago.Category: Small Engine
Show More
Show Less
Ask Your Own Small Engine Question
Customer reply replied 11 months ago
The unit starts with choke, but when throttle is accelerated the unit sputters and dies unless the throttle is returned to idle.
Answered in 2 hours by:
9/10/2017
Technician: Hank F., Technician replied 11 months ago
Hank F.
Hank F., Technician
Category: Small Engine
Satisfied Customers: 15,995
Experience: Certified on Onan and Generac generators
Verified

Hello, my name is ***** ***** I am going to assist you with this.

This is a classic symptom of a carburetor that has become plugged with varnish.

As gas gets old, it turns to varnish and clogs up the passageways inside the carburetor, not allowing enough gas to get to the engine.
Today’s gasoline formulation goes bad in as little as 30 days.
This condition is cumulative. Every time gas sits, the varnish builds up just a little more, like coats of paint, until eventually gas can not flow. It will not happen overnight, but the symptoms can show up all of a sudden, even while simply stopping to refill with gas.
The use of fuel additives, such as Sta-Bil or Sea Foam will not stop this process from happening. They will greatly slow it down, but the gas will still go bad.

This can also happen even on a brand new engine or brand new carb. When the carb is built, it is run at the factory to tune it.
After tuning, they do not always get properly cleaned, or may not have enough/any preservative injected. Believe it or not, this is actually fairly common.

When this happens, either the engine simply will not start, or it will not run without the choke on (this reduces the amount of air getting pulled into the engine, changing the fuel/air mixture), or it will run but surges.

Another issue that varnish in the carb can cause is that the varnish may not allow the float needle to seal properly against the seat, causing the flow of gas to not shut off when the bowl is full. The result will be gas overflowing the carb and running into the cylinder, and possibly out the air intake. If the gas gets into the cylinder, it will seep past the rings and down into the crankcase. This will be evidenced by your oil level being over-full and/or the oil smelling like gas.
If this is the case, you will need to change the oil and filter, if it has a filter.
Varnish can also cause the float needle to stick shut, and not allow any gas to flow from the carb bowl into the engine.

The only 2 solutions are to either replace the carburetor or give it a good, thorough cleaning.
When removing the carb, make sure to take a good picture, or make a good drawing of where all springs and linkages are attached. This will make reassembly much easier.
Most people believe that cleaning a carb involves removing the bowl and wiping it out, then spraying some carb cleaner through it.
This is simply insufficient. It takes months or years for this accumulation to build up – it just can not be removed in minutes.

To properly clean the carb, you must remove it, disassemble it (making sure to remove all non-metal parts), and soak it in a commercial solvent for several hours. Soaking it overnight is even better.
Then clean all solvent off with a spray type carb cleaner, making sure to get lots of cleaner into every hole and passage there is. Pay special attention to the tiny holes in the bore of the carb, under the throttle plate for the carbs that have these holes. Use lots of cleaner. And make sure to wear safety goggles to avoid getting the over spray into your eyes. There will be over spray.
Dry the carb with low pressure compressed air.
When reassembling the carb, make sure to use a carb kit, when one is available for your carb.

Occasionally, even a good cleaning is not going to be sufficient, and you may end up having to replace the carb anyhow. Be prepared for this.

Ask Your Own Small Engine Question
Technician: Hank F., Technician replied 11 months ago

Was this what you wanted to know?

Ask Your Own Small Engine Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a technicianLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask Hank F. Your Own Question
Hank F.
Hank F.
Hank F., Technician
Category: Small Engine
Satisfied Customers: 15,995
15,995 Satisfied Customers
Experience: Certified on Onan and Generac generators

Hank F. is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

You did one super job of explaining to me everything there is to know about this fridge. I'm looking forward to asking you questions in the future.

JimmyBagley, IA

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

< Previous | Next >

Meet the Experts:

Curtis B.

Curtis B.

Technician

15,517 satisfied customers

have worked on and around most engine models for 35 yrs./Polaris ATV expert

Rick

Rick

Factory Authorized Trainer

4,218 satisfied customers

Outdoor Power Equipment technical trainer since 1990, covering eight states.

Jon K.

Jon K.

Small Engine Diagnostic Expert

2,995 satisfied customers

Gold certified Stihl tech, Service Manager for a rental/repair shop.Certified in most small engines

James W

James W

Small Engine Troubleshooting Expert

2,986 satisfied customers

7 years as Mechanic & Parts Manager for Brother who has Owned Lawn & Garden Repair shop for 35 years

Vince O.

Vince O.

Small Engine Technician

2,927 satisfied customers

Over 30 years experience repairing lawn and garden equipment. Chainsaws, mowers,blowers and trimmers

Wayne

Wayne

Engine Rebuilder

2,041 satisfied customers

many years on egine rebuilding, lawn mower,roto tiller,Truck,and small engines

RUSS

RUSS

SERVICE TECHNICIAN

1,723 satisfied customers

28 YEAR SERVICE TECHNICIAN

< Previous | Next >

Related Small Engine Questions
Generac 15000 portable, stalled outn whitish smoke from air
generac 15000 portable, stalled outn whitish smoke from air filter arean tried to restart, sputtered, stalled white smoke from exhaust pipe in addition to oil build up in air intake area and oil soak … read more
Hank F.
Hank F.
Technician
High School or GED
15,995 satisfied customers
I have a Generac 58871 s|nthat won't start. I change the
I have a Generac 58871 s|n(###) ###-####that won't start. I change the fuel shutoff solenoid and the gas regulator assembly. Barely, spark plug, starter, air and oil filter new, an,d oil level ok … read more
Hank F.
Hank F.
Technician
High School or GED
15,995 satisfied customers
I have a generac 17500 watt generator, and after hurricane
I have a generac 17500 watt generator, and after hurricane Irma, we connected it to our house with the transfer switch in place, fired it up, and it worked for about 5 minutes than stopped producing e… read more
Hank F.
Hank F.
Technician
High School or GED
15,995 satisfied customers
Generac generator has been running 2 days and suddenly died
Generac generator has been running 2 days and suddenly died its has been 4 hours pass engine cooled already every time try to manually turn on "high temp" should field refilled already … read more
Hank F.
Hank F.
Technician
High School or GED
15,995 satisfied customers
I have a 15000 generac generator. How do I know if it's over
I have a 15000 generac generator. How do I know if it's over heating. I went outside and the exhaust pipe was red. Like it was really hot. The generator had been tuning for 2 hours. … read more
Hank F.
Hank F.
Technician
High School or GED
15,995 satisfied customers
I am in FL and trying to get my g15KW Generac running. It
Hello, I am in FL and trying to get my g15KW Generac running. It cranks for a few seconds, then shuts down with a overcrank fault. I"ve charged the battery to be sure it gets strong crank. I'm looking… read more
Hank F.
Hank F.
Technician
High School or GED
15,995 satisfied customers
Having same problem with 15000 centurion generator as person
Having same problem with 15000 centurion generator as person 4 years ago, disconnect ground wire and it will run but will not shut off with the rocker switch … read more
JON
JON
Master Service Tech
MASTER SERVICE TECHNICIAN
1,877 satisfied customers
My new DuroMax XP10000EH dual fuel portable generator will
My new DuroMax XP10000EH dual fuel portable generator will on run on full choke. … read more
Hank F.
Hank F.
Technician
High School or GED
15,995 satisfied customers
My Generac 15 KW Generator will start for 3 seconds and
My Generac 15 KW Generator will start for 3 seconds and shuts off. The red light appears for overheating. I am hooked up to natural gas. Is there a filter on natural gas? … read more
Hank F.
Hank F.
Technician
High School or GED
15,995 satisfied customers
I have a Generac 30 KW Quietsorce 12 years old and in good
I have a Generac 30 KW Quietsorce 12 years old and in good condition. It runs on propane and it keeps overspeeding.… read more
Wayne
Wayne
Engine Rebuilder
Vocational, Technical or Trade Scho
2,041 satisfied customers
I Have A Generac 15000 Watts Portable Gas Generator To Power
I Have A Generac 15000 Watts Portable Gas Generator To Power My Engine Repair Shop Runs Good At Idle Produces 120 Volts With No Load But When I Load it Down With Just 100 W Bulb Trouble Light The Gove… read more
Hank F.
Hank F.
Technician
High School or GED
15,995 satisfied customers
I have a 10 kw generator. tries to start, shuts down on
I have a 10 kw generator. tries to start , shuts down on overchrank. noticed choke stays closed. unplug wire for choke, it will start… read more
Hank F.
Hank F.
Technician
High School or GED
15,995 satisfied customers
I have an 8kw generac standby natural gas generator...it
I have an 8kw generac standby natural gas generator...it sputters when it tries to start and eventually stops. I smell natural gas after the generator stops...is this a mixture problem, amount of gas … read more
Hank F.
Hank F.
Technician
High School or GED
15,995 satisfied customers
I recently purchased a Generac model 5858 and I am having a
I recently purchased a Generac model 5858 and I am having a problem with it. After it has run and shut off, when I try to restart it, it backfires through the intake manifold. Sometimes it backfires s… read more
Hank F.
Hank F.
Technician
High School or GED
15,995 satisfied customers
Hank F. gave me a solution for my Generac Model 6053-0. I must
Hank F. gave me a solution for my Generac Model 6053-0. I must apologize as I had other projects I didn't pay much attention before accepting the solution. The solution given didn't seem logical as th… read more
Hank F.
Hank F.
Technician
High School or GED
15,995 satisfied customers
I purchased a Generac 6800 watt unit some years ago for the
I purchased a Generac 6800 watt unit some years ago for the Y2K scare. Due to hurrican Irene which hit my pa community this weekend, I used my generator for the first time. Same was filled with oil an… read more
ranwell1
ranwell1
CEO
High School or GED
5,039 satisfied customers
Generac 17kw (mod.(NNN) NNN-NNNN generator, last auto (exercise)-cycled
Generac 17kw (mod.(NNN) NNN-NNNN generator, last auto (exercise)-cycled in January, error message STOPPED - Under Voltage. Reset the display, set the auto exercise start to 5 min. from now, started, i… read more
Hank F.
Hank F.
Technician
High School or GED
15,995 satisfied customers
I have an RV Generac generator 6500. After running for a period
I have an RV Generac generator 6500. After running for a period of time, the choke will come on and cause the generator to sputter and run rough. Also, the exhaust is blue and it uses a lot of oil. Th… read more
Hank F.
Hank F.
Technician
High School or GED
15,995 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x