A Carburetor Fix Many Mechanics Don’t Know!

Diagnosing and repairing both 2 stroke and 4 stroke small engine carburetors is something even experienced mechanics can have difficulty with. Here I show a common fault that few people know about and how to repair it!
Engine bogging and stalling, hard starts and even your purge bulb sucking air are all symptoms of the accelerator pump failing! This problem affects both name brand carburetors from Stihl, Husqvarna, Echo as well as after market copy carburetors or clones. This video will save you time, money and frustration by teaching you how to repair carburetors found on your chainsaws, weed eaters, lawn mowers, leaf blowers and many other other small engines at home without any specialist or expensive tools!

Watch this video next:

JIS SCREW DRIVER:

TOOLS I USE:

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00:00 Small engine carburetor repair.
00:50 What is carburetor bogging and how to overcome it.
01:39 The accelerator pump and how it works.
02:32 Purge bulb won't fill with fuel.
02:52 Diagnosing an accelerator pump failure.
03:25 Replacing a carburetor - it is worth it?
03:34 Disassembling the carburetor.
04:00 Essential tool to service a carburetor.
05:59 Where to buy replacement parts for a carburetor.
06:18 Rebuilding a carburetor with new parts.

#carburetorrebuild #stihlcarburetor #husvarnacarburetor #primerbulb #enginerepair

[tomrogers]

So at 72 years old and a retired small engine mechanic, I’m now just learning of a JIS screw head! Best kept secret in the world! I’ve always just used Phillips.

[logger]

Thank you for teaching, an old dog new tricks. I am a 73-year-old retired engineer, who has tinkered with engines and all things mechanical & electrical ever since I was eight years old. Very grateful to my Father, who allowed me to fail and learn from failure.

I even owned an original McCulloch chainsaw, which was a beast to keep running, but 20 times faster than an ax. I still fix my own carburetors and a lot of carburetors for other people. But like others, I never knew about the accelerator pump on the small engine carbs. Again, many thanks !!

[brianb]

Never had a clue this was a accelerator pump. Awsome stuff.

[justinanderson]

Another brilliant video thanks Tom. It’s great that you don’t rush through the explanation of how things can work. I especially appreciate the way that you tell us what not to do and how to avoid rookie errors. Well done 👌🏻

[victorsabatino]

I love the specialized info that is available here...and the gutsy way that Tom removes tiny parts from a carb on a tree stump! I always use a work bench and a white rag to make things easier to see!

[robbyclark]

Man, I’ve owned my lawn service 36 years. Prior to the introduction of ethanol fuel I rebuilt more than 50 zama cards on stihl 2 stroke lawn equipment. I started having problems with welch plug sealant loosening up and allowing an internal leak between a couple of the passages. I became disappointed and just started buying Stihl OEM carbs I feel lucky to have lived back when it was a black art to tinker with carburetors. And honestly…..I just threw away at least 100 carburetors that I had replaced after I quit rebuilding them.

[WECB]

Extremely useful tutorial, accurate and concise. I wish more presenters were like this. BRAVO!

[RMosher]

Going to add this to my ever growing knowledge of small engine carbs. Great stuff, thanks man.

[jimbrewer]

Excellent info. I would venture to say not many people know about that pump and o-ring.

[TimDrake-vnwo]

I am still using the same Husqvarna Rancher 44 and 61 that I bought in the 80s when they made them in Sweden . Thanks for explaining the carbs I have rebuilt them carefully and they still work quite well .
I always keep the extra parts included in the rebuilding kits and they can be used for repairs if you punch new holes where they don't match your carburetor .
That zip lock bag of extras is a treasure .

[trxracer]

I've worked at a small engine shop for several years. I have read dozens of repair manuals, taken brand certification tests, and spoke to the other techs I work with. Yet, I have never been told about this or showed this before. I cannot wait til my next "problem child" comes along so I can try it. THANK YOU.

[ChrisR]

So some of the accelerator pump carburetor models have a metal plug pressed into the top of the 3rd bore. Getting that plug out can sometimes be tricky as you have to remove the throttle shaft first and then hold the pump piston down while using an angled pick to drive the cap out.

Also it is worth noting that usually if you look at the pump piston you'll see the side of it is scored up badly and that scoring is transferred to the bore which is what tears up the o-ring. The way the piston is operated the force applied to it isn't straight down, it's off center and as such the bore gets ovaled out and even with a new pump piston they usually don't go for very long before developing another vacuum leak in that area.

I always recommend replacing an accelerator pump model carb once the pump/metering gaskets are used up.

[alageshan]

Today I learnt the difference between JIS and Phillips head screws and how to identify them.👍

[tinkeringtaylor]

What a excellent information video Tom👍, i can see a few small engine repair guys checking through there old carb boxes 😂

[cedhome]

Bought a new carb for £6 but good to see you fix this anyway 👍

[freddaniali]

I did this to my Ryobi Chainsaw and it completely fixed the bogging issue! Thank you so much for this!

[IndianaDoug]

Always good stuff here👍🏻
I always tell everyone, 90% of the time, it’s the carb giving the issue.

[sweber]

This was the best and most educational video I've seen in a long time!! wow thank you! My Ryobi 4 stroke weed eater is now giving me issues after 4 years and it bogs like crazy, also has lost power so much! Even at full throttle it barely does much....now I know what to do! Thanks again your videos are so helpful! 😀cheers from Canada

[allanfranco]

IVE BEEN A AUTOMECHANIC AND SMALLENGINE MECHANIC FOR OVER 40YEARS AND I NEVER KNEW ABOUT THIS ACCELARATOR PUMP CIRCUIT PROBLEM, THANK YOU SO MUCH, IM 65YEARS OLD BUT ALWAYS LEARNING NEW THINGS THANK YOU SO MUCH FOR SHARING YOUR KNOWLEDGE, NOW I KNOW WHY SOME OF THOSE CARBS HAD THESE PROBLEMS AND I DIDNT KNOW WHAT WAS WRONG

[ajohnson]

Hands-down one of the top three best videos I've seen on YouTube in regards to a two-stroke carburetor repair. I honestly can't wait to watch more of the videos that you have and you sir just made a subscriber out of me with just one video. Not that it matters Terribly to you or anybody else in particular but I can count on 2 hands the number of times a channel/content maker on YouTube managed to get a subscription out of me with just one video :) you earned it IMHO and the only thing I'm disappointed about is the fact that my lunch break is over in a couple minutes and I will have to wait until I get home from work to see what other topics you cover and watch some more of your videos!! 🎉