Small Engine

Small Engine Troubleshooting Problems? Ask a Mechanic Now.

Ask an Expert,
Get an Answer ASAP!

Small Engine
This answer was rated:

I have a Briggs and Stratton 31B707 Engine with a Nikki Carb.

The motor sill start just...
I have a Briggs and Stratton 31B707 Engine with a Nikki Carb. The motor sill start just fine, run at low speed for about 5 seconds, then just quit. All the safety switches seem to be functioning properly. I'm thinking a carb problem. Any input? Thanks
Show More
Show Less
Ask Your Own Small Engine Question
Answered in 23 minutes by:
8/14/2012
James W
James W, Small Engine Troubleshooting Expert
Category: Small Engine
Satisfied Customers: 3,708
Experience: 7 years as Mechanic & Parts Manager for Brother who has Owned Lawn & Garden Repair shop for 35 years
Verified

James W :

Greetings, My name isXXXXX and I am here to help the best I can. My goal is 100% satisfaction. Let's get started.

James W :

you are describing classic carburetor problems

James W :

assuming that the gasoline is getting TO the carbuertor but not getting through the carburetor

James W :

then either the afterfire fuel solenoid is shutting the gas off

James W :

inside the carb, or the carb is dirty

James W :

the solenoid is there to shut the gas off when you turn the key off to prevent backfires

James W :

it must have 12V at all times, or the plunger extends and off the gas goes

James W :

Most likely you have a fuel delivery or fuel quality problem.


As engines sit or get older, fuel that is left in the carburetor can turn to gum and varnish and cause this and other problems.


Also, any gasoline that was left in a gas can for a period of more than 30 days must be discarded because it also has begun to turn to varnish.


Today's gasolines contain MTBE and alcohol. (Ethanol) They turn to "Junk and garbage" very quickly. Alcohol absorbs water. And they call it "Oxygenated fuels! It is the oxygen (and the water) that breaks down the organic compounds in the fuel and turns the gas to "Garbage" (Gum and varnish) The fuels we had just a few years ago had no alcohol in it and would store for longer periods of time before going stale.


Fuel stabilizers do almost nothing to prevent the fuel from going bad with the changes in today's fuels. The whole point of a fuel stabilizer is to form an oily film on the surface of stored gasoline whether in the tank or in a gas can. The idea was to keep oxygen away from the gasoline to prevent breakdown. Since the fuel is already oxygenated, the fuel stabilizer concept is null and void. These fuels start to degrade immediately upon the addition of the ethanol.


Do not buy gas from the "Discount" Stations. The discount stations get a reduced price on gas because they may be buying fuel that is nearly 30 days old already. You may be getting fuel that's nearly stale right from the pump when buying from a discount station. Purchase your fuel from the well-known stations such as Shell, BP, Sonoco, Phillips 66 etc.


More than 70% of all of our repairs in our small engine repair business are due to these same issues. You most likely have dirt, gum, varnish...etc in your carburetor plugging up the small passageways and jets in the carburetor.


The carburetor will need to be cleaned and overhauled as well as the rest of the fuel system.


 



  • If you plan to do the work yourself, take pictures with your digital camera or at least make a drawing of where all the linkages, gaskets, and component parts go. Correct reassembly is critical.

  • Remove the carburetor from the engine.

  • Remove all of the non-metallic parts since the carburetor cleaner will cause them to be disfigured decompose and plug the carburetor as time goes on.

  • Clean all parts with carburetor cleaner. You will want to SOAK Only the metallic parts in a cleaner bath.

  • Blow out all the small holes and passageways with compressed air.

  • Use a tiny stiff wire such as is found on the twist tie on a loaf of bread or on a garbage bag to open all tiny passageways found in the carburetor such as in the screw, nut, or jet holding the bowl of the carburetor on (if it has a bowl). Make sure to look for tiny holes in the bottom and side threads of the bowl nut or nozzle a make sure they are clear with the wire.

  • Wash the carburetor cleaner off of the metal parts by washing them in warm, soapy water then rinsing with clean water.

  • Dry all carburetor parts by blowing it off with compressed air.

  • Make sure that all the passageways are blown dry before reassembling (you do not want water back in the carburetor).

  • Reassemble the carburetor using a NEW carburetor rebuild kit.

  • NOTE: DO NOT TRY TO REASSEMBLE WITHOUT USING A COMPLETE CARBURETOR KIT! You will just end up having to do the job again.

  • Find the Model, type and serial or code numbers off of the engine and take them to your local dealer to get the carburetor repair kit.

  • ALWAYS clean the fuel tank and replace the fuel line when doing this repair or you may have to do it all over again. The inside of the fuel line disintegrates over time and these small pieces of rubber will plug up the carburetor too. Dirt and water from a dirty fuel tank will also plug up the carburetor. If this happens, you will be starting over again from the top.


In an Emergency such as a blizzard where you cannot get out to buy a carburetor kit until the plows come through, or during an emergency power outage and you need a generator running even if it runs poorly, you might try the following if your carburetor is the type that has a bowl. Sometimes this procedure works:


While the carburetor is still mounted to the engine:



  • Pinch the fuel line with a pair of vice grips to stop the fuel from going to the carburetor.

  • Remove the bowl nut (or nozzle from the bottom of the carburetor and let the fuel drain from the bowl.

  • Carefully remove the bowl from the carburetor without letting the needle and seat and float fall out of position (if it does, no big deal, but you will have to reassemble it, which is harder with the carburetor on the unit).

  • Dump all of the Gunk out of the bowl and put the bowl back into position.

  • Use a tiny stiff wire such as is found on the twist tie on a loaf of bread or on a garbage bag to open all tiny holes in the screw, bowl nut, or nozzle that was holding the bowl of the carburetor on (if it has a bowl). Make sure to look for tiny holes in the bottom and side threads of the bowl nut or nozzle a make sure they are clear with the wire.

  • Reassemble and see if you got lucky.


You may be able to finish the job at hand then clean and overhaul the carburetor correctly when you have more time and a new carburetor overhaul kit.


The nut that holds on the carburetor bowl has several small holes in it. Some are on the sides and one may be in the end. In order to completely clean the carburetor correctly, you Must clean these holes with a tag wire or a jet drill. (If a jet drill is used, DO NOT use a drill that is bigger than the hole or the engine will run too rich.)


 


If you don't feel comfortable with these kinds of repairs, or if the carburetor still doesn't work correctly after your attempt, I would suggest sending it to a profession repair shop with a reputation for having friendly, knowledgeable, experienced service technicians. It would be best to take it to someone who has an "Ultra-sonic" cleaning machine. This machine uses a very mild carburetor cleaner in concert with ultrasonic vibrations to get the very small passageways clean. This method is very effective even when traditional methods fail.


Here is where you can get an inexpensive "Ultrasonic Cleaning Machine"


http://www.harborfreight.com/catalogsearch/result?category=&q=ultrasonic+cleaner


There is a New Product that you can try which is guaranteed to work or your money back (per the manufacturer).


http://www.b3cfuelsolutions.com/html/mib.html


It is designed to help clean the carburetor without damaging the diaphragms and rubber parts like regular carburetor cleaner. Click on this site and it will tell you all about it. http://www.b3cfuelsolutions.com/html/mib.html


The mechanic in a bottle is NOT a conventional carburetor cleaner.


It actually breaks down the varnish into it molecular components and it completely dissolves. It DOE NOT clog up the jets as conventional carburetor cleaners do. Conventional carb cleaners just loosen the varnish and the varnish particles will go into the jets and filters and clog them up.... usually causing much more problems that was originally there. The conventional carb cleaners also will loosen the "GUMK" that has formed in the gas tanks and cause all of that gunk to go through the carburetor as well.


 


The Mechanic in a BOTTLE is a completely revolutionary product that will in many cases alleviate the need to tear the carburetor down and rebuilt it..... unless there is mechanical wear and tear that would require that parts be replaced.


 


In addition, the special formula actually is designed to soften and restore the rubber parts in the carburetor such as the needle and seats and gaskets.


 


Mechanic in a bottle is NOT a cure-all but it can help customer get going in many cases without them having to tear the carburetor apart. If the customer is NOT mechanically inclined, it might save them a trip to the repair shop.


 


Yes I was very skeptical about this product when I first was introduced to it, but the Distributor demonstrated it and we have tried it on many occasions with terrific results.


Otherwise you will have to clean and rebuild the carburetor.


Please feel free to ask follow-up questions so that we can always arrive at the correct solution. We want you to be 100% satisfied.

James W :

Full Size Image

James W :

most of the nikki carbs do not have a bowl nut, but instead have the afterfire solneoid, but SOME have both

James W :

there may also be other locations where the stiff wire may be needed to probe the tiny holes and orifices to get them clean

James W
James W, Small Engine Troubleshooting Expert
Category: Small Engine
Satisfied Customers: 3,708
Experience: 7 years as Mechanic & Parts Manager for Brother who has Owned Lawn & Garden Repair shop for 35 years
Verified
James W and 87 other Small Engine Specialists are ready to help you
Ask your own question now
Ask James W Your Own Question
James W
James W
James W, Small Engine Troubleshooting Expert
Category: Small Engine
Satisfied Customers: 3,708
3,708 Satisfied Customers
Experience: 7 years as Mechanic & Parts Manager for Brother who has Owned Lawn & Garden Repair shop for 35 years

James W 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

14,332 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

3,708 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

2,853 satisfied customers

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

RUSS

RUSS

SERVICE TECHNICIAN

1,723 satisfied customers

28 YEAR SERVICE TECHNICIAN

Wayne

Wayne

Engine Rebuilder

1,553 satisfied customers

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

< Previous | Next >

Related Small Engine Questions
I had to put a new ignition switch on my gravely. I wired it
i had to put a new ignition switch on my gravely. I wired it the same as the old one and it wouldn't start. I had no spark. One terminal someone had connected a second wire so on a hunch i cut that wi… read more
Curtis B.
Curtis B.
Technician
Associate Degree
14,332 satisfied customers
I have a part number for a dip stick for a onan the parts
I have a part number for a dip stick for a onan the parts number is(###) ###-####.I cant find this any were … read more
JON
JON
Master Service Tech
MASTER SERVICE TECHNICIAN
1,489 satisfied customers
I have an Aries snowblower 921038 ser104336 only 2 years old
I have an Aries snowblower 921038 ser104336 only 2 years old only used twice but I never drained fuel over those when I first started it started right up but it surges so I drained the tank and put ne… read more
Wayne
Wayne
Engine Rebuilder
Vocational, Technical or Trade Scho
1,553 satisfied customers
How do I start the 24 inch snow blower. And OIL. I am not
Of course. I am 68educated but not mechanically inclined. I just cannot remember how to get it started.t … read more
Curtis B.
Curtis B.
Technician
Associate Degree
14,332 satisfied customers
I have a model 13an77kg011 my son ran out all the oil and
hi I have a model 13an77kg011 my son ran out all the oil and now it sounds bad and black smoke coming out the muffler it has 17.5 eng now what can I get to replace it with … read more
Wayne
Wayne
Engine Rebuilder
Vocational, Technical or Trade Scho
1,553 satisfied customers
Can my poulanpro 50 be c0nverted to a larger chissel chain
can my poulanpro 50 be c0nverted to a larger chissel chain it has a 3/8 now. … read more
JohnF2015
JohnF2015
High School Diploma
1,167 satisfied customers
We just got our snowjoe 18 inch 40v max snowblower. It went
We just got our snowjoe 18 inch 40v max snowblower. It went on and worked for a while but then wouldn't go on after stopping it to clear away snow. Is there a trick to getting it started again? The ba… read more
Curtis B.
Curtis B.
Technician
Associate Degree
14,332 satisfied customers
I have a Honda E 2000 generator while running last weekend
I have a Honda E 2000 generator while running last weekend and it shut off and it would not restart checked feel was OK noticed no electrical spark when I pulled it over any thoughts… read more
Curtis B.
Curtis B.
Technician
Associate Degree
14,332 satisfied customers
Generator won't make 120 or 220 volts. Generac 20 years it
generator won't make 120 or 220 volts JA: What's the make and model of the generator? And can you guesstimate how old it is? Customer: generac 20 years it is a 6500 JA: Do you plan on doing the work y… read more
Hank F.
Hank F.
Service Technician
High School or GED
5,362 satisfied customers
2010 crosstour uses oil bad. 8 months. Is the rocker oil
2010 crosstour uses oil bad JA: I'll do all I can to help. How long have you been dealing with this? Customer: 8 months JA: Do you plan on doing the work yourself? Customer: yes JA: Anything else we s… read more
eauto
eauto
self employed
High School or GED
74 satisfied customers
Model 247.881731craftsman snow blower. 1 year old .ran great
model###-##-####raftsman snow blower. 1 year old .ran great first year. added stabil to store. start up this year and will only run on partial choke with out surging. … read more
JON
JON
Master Service Tech
MASTER SERVICE TECHNICIAN
1,489 satisfied customers
I changed the battery (TYPE 26 Duracell installed) after
I changed the battery (TYPE 26 Duracell installed) after yellow light code was check battery. Was still getting yellow light so checked battery it is fully charged. Changed spark plugs (.040 Gap) and … read more
Hank F.
Hank F.
Service Technician
High School or GED
5,362 satisfied customers
I have a question about my Craftsman Snowblower 8.5hp 26in.
I have a question about my Craftsman Snowblower 8.5hp 26in. dual stage. I need to know if it requires an oil filter when you change the oil. I went through the manual and couldn't find any information… read more
HVAC Guru
HVAC Guru
Service Technician
Associate Degree
682 satisfied customers
I have a quiet pack 75 D. It blew the the cooling belt and
I have a quiet pack 75 D. It blew the the cooling belt and we replaced it. Since then it is under powered and will run microwave but it takes 3times longer to heat coffee and lights flicker. … read more
Hank F.
Hank F.
Service Technician
High School or GED
5,362 satisfied customers
I have an Ariens 900 2 stage snow blower. Currently the
I have an Ariens 900 2 stage snow blower. Currently the engine continues to pulsate. Can't get the engine to remain at a solid throttle. I have to almost completely choke it to get it to be able to ru… read more
HVAC Guru
HVAC Guru
Service Technician
Associate Degree
682 satisfied customers
I got a tree limb caught in auger. Auger will not turn.
I got a tree limb caught in auger. Auger will not turn. Shear pins appear to be intact … read more
Wayne
Wayne
Engine Rebuilder
Vocational, Technical or Trade Scho
1,553 satisfied customers
I have a Quantum I/c 6.0 hp engine that wont start. It has a
Second opinion] I have a Quantum I/c 6.0 hp engine that wont start… read more
Wayne
Wayne
Engine Rebuilder
Vocational, Technical or Trade Scho
1,553 satisfied customers
Sears snow blower carburator is clogged, probably with gum
Sears snow blower carburator is clogged, probably with gum deposits. How do I repair or replace … read more
Curtis B.
Curtis B.
Technician
Associate Degree
14,332 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