How JustAnswer Works:

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

Ask bgsengineclinic Your Own Question

bgsengineclinic
bgsengineclinic, Small Engine Technician
Category: Small Engine
Satisfied Customers: 220
Experience:  Over 20 years of experience in Small engine repair, Kohler Certified Expert Technician, Self-Employed in my own dealership.
55943398
Type Your Small Engine Question Here...
bgsengineclinic is online now
A new question is answered every 9 seconds

have 026 stihl chainsaw fires up but when itake it off choke

Resolved Question:

have 026 stihl chainsaw fires up but when itake it off choke pull throttle it revs up then dies
Submitted: 2 years ago.
Category: Small Engine
Expert:  bgsengineclinic replied 2 years ago.

bgsengineclinic :

Carburetor needs to be adjusted - if it has limiter caps, you need to have it done at a professional shop that has the proper tools to adjust the carburetor to EPA specifications. However it is possible you also have an air leak - these have a rubber intake boot that sometimes can be torn, or the steel boot support insert is missing. Can also have a leaking crankcase gasket or leaking crankshaft seal.

bgsengineclinic :

basically it is running lean and needs more fuel - usually if it is a new carburetor, you'll more likely have an air leak problem - if fuel lines and filter are new, and carburetor is new, it's likely got a crankcase air leak somewhere - pulse hose, crankcase or cylinder gasket, crankshaft seals, or intake boot isolator, among other locations that can leak.

bgsengineclinic :

Would have to block off intake and exhaust and test with a crankcase pressure tester to check for air leaks, requiring special tools, and if it is an emissions compliant machine, carburetor adjustment requires specialized tools as well.

bgsengineclinic :

based on your symptoms, however that sounds almost classic case of leaking intake boot - what happens is it leaks air and goes lean - choke keeps it rich enough to run, but as choke comes off, it goes lean and revs up until it runs out of gas.

Customer:

ye idid adjust carb idid compression test it tested great .

bgsengineclinic :

compression test is not same as a leakdown test

Customer:

ok so it still may have air leak

bgsengineclinic :

leakdown test checks crankcase seals, gaskets and intake boot for air leaks - compression test won't check that. it requires steady crankcase pressure pulses to pump fuel in the carburetor

bgsengineclinic :

yes

bgsengineclinic :

leaking seals or gaskets it will usually start and run fine and then run out of gas when revved up

bgsengineclinic :

leaking intake boot is more of a match to your symptoms

bgsengineclinic :

other possibility, but remote, is plugged exhaust , but that acts a little different - more like it will idle but when revving up it stalls out

Customer:

i checked exhuust is good

Customer:

so i should start with replacing intake boot?

bgsengineclinic :

also if you can start and run at idle just fine, but it dies when you pull the trigger, may just be simple hesitation and idle side of carb needs to be adjusted richer - but, if it is like on throttle lock position, it starts on choke, and you take off choke, it then speeds up by itself and dies out without touching throttle, that's classic air leak in intake

bgsengineclinic :

you can check the boot by removing carburetor, check for the steel boot insert support, then use a finger to probe the boot and feel/ look for any tears or cracks in the rubber boot

bgsengineclinic :

may have to pull handle away from crankcase a bit to stretch the boot a little to find the crack or damage

bgsengineclinic :

or loose boot clamp where it clamps to the cylinder

Customer:

i did look at the boot it seemd fine

bgsengineclinic :

in a pro shop like ours, we will block off the intake and exhaust, plug the pulse hose, and pressurize the cylinder to 7 PSI through the spark plug hole, and then squirt soapy water over everything to locate the air leak - it should hold 7 PSI for 2 minutes

bgsengineclinic :

if it does not, it has an air leak.

bgsengineclinic, Small Engine Technician
Category: Small Engine
Satisfied Customers: 220
Experience: Over 20 years of experience in Small engine repair, Kohler Certified Expert Technician, Self-Employed in my own dealership.
bgsengineclinic and 3 other Small Engine Specialists are ready to help you

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. Jimmy Bagley, IA
< Last | Next >
  • 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. Jimmy Bagley, 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!!!! Alex Los 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. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, 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. Esther Woodstock, 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. Robin Elkton, Maryland
 
 
 

Meet The Experts:

 
 
 
  • Curtis B.

    Technician

    Satisfied Customers:

    6989
    have worked on and around most engine models for 35 yrs./Polaris ATV expert
< Last | Next >
  • http://ww2.justanswer.com/uploads/KO/koboma/2012-6-6_20917_DSCF1022.64x64.JPG Curtis B.'s Avatar

    Curtis B.

    Technician

    Satisfied Customers:

    6989
    have worked on and around most engine models for 35 yrs./Polaris ATV expert
  • http://ww2.justanswer.com/uploads/SM/SmEngPro/2012-8-5_3564_Rick1206290005Edit.fullres.logo.scrn.64x64.jpg Rick's Avatar

    Rick

    Factory Authorized Trainer

    Satisfied Customers:

    4126
    Outdoor Power Equipment technical trainer since 1990, covering eight states.
  • http://ww2.justanswer.com/uploads/GI/giftindex/2011-11-19_2715_JamesLWells500.64x64.jpg James W's Avatar

    James W

    Small Engine Troubleshooting Expert

    Satisfied Customers:

    2978
    7 years as Mechanic & Parts Manager for Brother who has Owned Lawn & Garden Repair shop for 35 years
  • http://ww2.justanswer.com/uploads/jonrk/2010-1-5_22551_jon.jpg Jon K.'s Avatar

    Jon K.

    Small Engine Diagnostic Expert

    Satisfied Customers:

    2950
    Gold certified Stihl tech, Service Manager for a rental/repair shop.Certified in most small engines
  • http://ww2.justanswer.com/uploads/MR/mr2cycle/2011-3-12_03458_sears.64x64.jpg Vince O.'s Avatar

    Vince O.

    Small Engine Technician

    Satisfied Customers:

    2374
    Over 30 years experience repairing lawn and garden equipment. Chainsaws, mowers,blowers and trimmers
  • http://ww2.justanswer.com/uploads/rheisnger/2010-12-31_010856_41385_100001225699183_7012_q.jpg RUSS's Avatar

    RUSS

    SERVICE TECHNICIAN

    Satisfied Customers:

    1723
    28 YEAR SERVICE TECHNICIAN
  • http://ww2.justanswer.com/uploads/BriggsEngines/2010-02-26_230200_n1834842973_4823.jpg CJBennett's Avatar

    CJBennett

    Small Engine Technician

    Satisfied Customers:

    623
    Briggs and Stratton Master Service Tech, Kohler, Tecumseh, Kawasaki certified. 18 years exp.
 
 
 
Chat Now With A Technician
bgsengineclinic
bgsengineclinic
Owner
202 Satisfied Customers
Over 20 years of experience in Small engine repair, Kohler Certified Expert Technician, Self-Employed in my own dealership.