Very good no nonsense information. Hats off to you. I repaired small engines as a side line many years ago and always learn something from you. Thank you, from the Midwest USA.
I thought you were working on a new mower until you took the cowling off. You have very good knowledge of carby internals of where the fuel and air should go.
Tom one of your best videos very informative and well put together. These carbs are a pain but good for business here in Canada. The jets are so small just a small piece of debris that gets through the fuel tank screen is enough to make it run poorly, hunt or not start at all. Those jets are only held in with O rings and if you ever get one that is flooding ie: low rpm and black smoke the jet has loosened off and fuel is bypassing the O ring. I know this for a fact when i kept using carb cleaner with the straw and was actually pushing the jet back in place without knowing it. Customer would use the machine for a lawn cutting and sometimes into the second cutting and it would flood out again. Not until i ran it in the ultrasonic cleaner did i find the jet falling out and realised the problem. Reinstalled the jet with some SealAll glue around the OD only pushed back in a voila good to go and still running smooth. It was cheaper than replacing the module which runs around $20 Cdn.
Excellent. Having tried many other suggestions to stop surging with no avail, the drilling out of the pilot Jet cured the issue on my B&S mower engine.
I have a Honda mower, it was surging & kinda struggling when going over tall grass. I took apart the carb & used the seafoam intake cleaner that comes with the red straw to sprayed the crap out of it & used the straw to put pressure through all those fine holes you pointed out. Put it back together and & added a bit of the seafoam you add to the gas tank as well. Problem solved, put new blades as well & that puppy is purring nice & now I can go over tall grass without stalling. And that was my 1st "taking a carb apart" job lol, glad I didn't wreck it! 😂
Thanks, had the same unit of the Yard Machines variety, the .035 drill to jet worked, adjusted valves too .. still had a little erratic running so I filled the tank and put a splash of water remover (methanol) in the tank and it smoothed right out.
Something to be extra mindful of when taking apart the E series carbs is making sure to keep track of the super tiny rubber tip that goes on the needle valve. If it ever pops off (doesn't take much for it to pop off) you'll likely never see it again. Your needle valve will not work properly without that tip so you might as well replace the entire carb because a replacement needle valve is only a few bucks cheaper than the entire carburetor
By the way, this applies to the ones with plastic needle valves - not sure if the metal ones like the one in this video have a tip that can pop off as easily but I would be cautious and handle the needle valve over a container or something that could catch the tip if it did pop off.
Great video, thank you for making and sharing. One thing that shocked me though, is to see that even lawn mower manufacturers are now using cheap plastic parts to build. Disgraceful when you think about it. Plastic parts are cheaper to make, break down faster/or more often and the lawnmowers cost same if not more than the mowers made back in the day using non plastic parts.
Thanks to your video our mower finally stopped surging. The pilot jet was totally blocked, so I just cleaned it with 0,35 mm. In our case, the pilot jet was behind ball bearing (06:02). I drilled 1,2 mm hole just behind the ball bearing in order to get it out and then filled it with part of an “O” ring 1,5 mm. Thank you
Very good tutorial. My Honda gen carb was surging on a new Amazon carb. Did not have micro drills and did not want to alter carb so sent it back. Rebuilt my old carb which cost more than the new carb.
Thank you :) glad it helped you build yours! It’s worth saving your original carb for exactly this reason, because they work and do so 100x better than the junk that is online :) well done for fixing your own 👍
Be mindful when removing these carbs from the intake tube that you don’t lose the black o-ring. They can come loose when pulling carburetor off the tube, or stay on the intake tube. There is a white o-ring too. Upon reinstallation, seat the black o-ring into the carburetor first, then the white one, then push back onto lightly lubricated intake tube. Don’t forget to connect your governor linkage pushrod and spring first. If you have a autochoke (common on Toro Recycler), there will be a second pushrod linkage on the choke control arm, which can be tricky trying not to bend and deform the pushrod. Mind that the plastic pusher foot on the autochoke pushrod connection piece atop the carburetor is positioned on the correct side of the choke control arm where the foot makes contact, so as when the exhaust heats the autochoke actuator and actuates the pushrod, the foot pushes the choke linkage to the open position. It is possible to assemble with the foot on the opposite side of the choke arm. A heat gun is a good way to test an autochoke bi-metal actuator for proper operation.
Mower started surging so I did a deep clean and fully cleaned every bit following the video and it started first try but still surges. Looks like I'll have to buy a micro drill set and make the jet bigger.
Excellent video. Would you place that plastic carb in your ultrasonic cleaner? I also wonder if drilling out the jet was necessary even though I think they set them on the small side for cleaner air. Loved the "check list" too. Thanks Tom!
You need to check the priming bulb too - they perish and can let air in even when they don’t show any fuel leakage. Top tip for all these machines that are only used seasonally - ONLY USE PREMIUM GRADE FUEL. Many of the E5 Petrol’s are just Petrol - there is no ethanol in many of these premium fuels (UK law states it must be marked and sold as E5 if it has less that 5% ethanol - which of course pure petrol is!) Ethanol causes the petrol to spoil within a few months and destroys many of the plastic fuel lines, seals etc. Nitrile and butile rubbers (O rings) are mostly OK, but plastic fuel line especially will just rot if ethanol is present (yes, I am talking to you Stihl). You do not need to buy the over-priced ‘petrol substitute’, just straight petrol is fine, but do drain it out if you’re laying up the machine for months.
While I greatly appreciate the detail and effort of this video, if the gaskets need replacing or the rubber tip of the float valve plug has deteriorated (as mine had), a rebuild kit containing these items (Briggs & Stratton 594636) costs at least $37, whereas a replacement carb with two air cleaner gaskeys costs only $9 on eBay (mine was the two control rod version). If you DO buy a replacement carb, be sure to blow into the gas inlet to ensure flow. I installed one without doing this and the valve was stuck closed. Upon comparison with my old carb, I found that the float valve seat was insufficiently recessed. A 3/16" Allen wrench socket wrench adapter was inserted into the float valve tube and a large Vice Grips used to press the valve seat to the proper depth. Fortunately the valve plug rubber tip was undamaged by the manufacture's assembly abuse. O&BTW, if the bowl is installed 180° out of the correct position, surging will also occur. :/ UPDATE: The surging was caused by a too large ID carb/engine O-ring allowing unregulated air into the engine. Why bother manufacturing something this complex, yet screwing up these minor details?
What causes this with a brand new carburetor? Can’t be the filter I don’t think. The gas leaks out when removing the gas line. Throttle just won’t stop surging. Throttle spring has good motion. It’s a craftsman m230 b&s 7.25 163 ohv.
Very likely the jet is too small, or an air leak :) when it’s running you can spray some brake cleaner around the area where the carb fits to the engine, intake and cylinder head gasket areas. See if this changes the rpm. If not, you may need to drill the jet bigger.
Thanks for sharing! I haven’t come across it before but It’s logical that If the engine is over speeding it’s demanding more fuel which stock settings may not offer and then surge. Thanks :)
It is not at all unusual for mowers, generators, weed whackers & the like are put out with the trash. They are absolute crap. It would not surprise me to find plastic pistons soon ! Great video my friend.
Yah the 125cc Briggs have more problems with surging then 140cc and bigger. If a cleaning doesn’t fix some ppl enlarge the main jet with a micro drill bit by one size as a last resort.
Hey Paul, my apologies! I have used this set extensively for the last 4 years. amzn.to/4czLtDK It's been great. My one tip, if the drill bit slips in the pin vice, tighten the head up in a vice holding the other end of the pin vice with pliers! Also, doesn't hurt to buy 2 sets, the drill bits are TINY and when you're learning how gentle you need to be you'll likely snap a few - i have 2 sets :P
I have a lawn boy 10632 with 5.5 brigs and auto choke. Was surging then stopped starting all together. This was after already cleaning carb. Installed a new carb today.. runs good but when you move the mower back and forth it starts surging then if let sit it clears up.
Great vid sir , i work on more stuff like toro and ventrac , iseki machines but the guys in other bay’s work on those type mowers , they look annoying to work on , one thing is the flat head engines seem to have less problems than over head valve newer stuff , to much to go wrong and cheaper made , even som of the Honda engines (certain models) are having issues with decompression cams failing on new machines ,,old stuff is better but law of omissions stopped the flat heads production sadly .. 👍🙂
When there is no load it will be running on the pilot circuit. If it surges then, it’s not getting enough fuel through the circuit. Either it’s blocked or needs to be drilled.
Great video, very clear to follow. My mower was surging and running for a minute or two then cutting out, I have replaced the carburettor and air filter and it is still surging and cutting out but will run for maybe 4 or 5 minutes now before cutting out. It also requires priming every time to start. There is new fuel in it and no water in the fuel tank. Does this give you any clue as to what the problem may be please? Thanks in advance
@@VintageEngineRepairs thank you for the reply, the filter at the bottom of the tank looks clear and I can't see any splits in the fuel line. I think I might have to order some micro drills and have a go at increasing the bore of the air jet.
I had luck by drilling out the lower main jet because the mower likes to mostly run off the pilot jet it's very starved underload by that smaller main jet down bottom I gained and extra pony in the cut when I went up a size with that main jet ran way better it probably could.go up a couple sizes on these carbs possibly you may need to up both got the micro drill bits off amazon just don't break them off in a pilot jet. I did that to one I can't say if I was forceful or the drill bit wasn't very good to begin with their so tiny
It’s not been my experience, replacing them typically means doing so with Chinese copies which don’t work well if at all. You’re throwing money away in my opinion. Rebuild the genuine one whenever possible!
@@VintageEngineRepairs thank you for the response. Do you think lawn mowers will go fuel injection like generators and chain saws or they will be banned first for “cLiMatE cHaNGe 🤡” before then
Hi Tom, I appreciate the vid. My 3 y.o. Cub Cadet snow blower sat dormant last winter and I forgot about the gas. It fouled the carb, so I drained it and cleaned the carb, making sure every hole, passage etc was squeaky clean. It started on the first pull, but it surges when it never did before. This is a puzzler for me. Any suggestions?
@VintageEngineRepairs oh yes it will if it is not fully open to let the exhaust out it will surge and die under a load I just had one come to my shop like a week ago and that was their problem.
@@greenreviews3391 interesting I have never had one surge with a blocked muffler, I have had them struggle to go much above a slow idle though. Thanks for sharing!
@VintageEngineRepairs me either.. I felt exhaust coming out so I didn't think to check it so I bought a new carb was only $23 put it on and changed nothing.. which led me back to air or gas issue. Started out removing variables. Started with sir filter and made my way to remove the exhaust and bam pur like a kitten found a nest in the exhaust. Wasn't fully closed but enough to cause problems after cleaning and reassemble.. ran good it was a 6.5 kholer engine on a wood splitter
Where and what is the (stiff) "diaphragm" that you refer to in your checklist as shown at the 1:36 min. mark, as I don't see this as being otherwise specifically shown &/or visually identified, anywhere else in the video? Thanks, in advance.
@@VintageEngineRepairs Okay. Good to know . . . which leads me to another question, which is, Is the mower in this video a 2-stroke Victa mower, or a 4-stroke, and what's the difference between a 2-stroke vs a 4-stroke . . . is it that a 2-stroke requires an oil to gas mixture in the furl tank, because there’s no oil inlet, as opposed to a 4-stroke, which has a fuel tank for the gas, and a separate inlet for the oil - where the two are not mixed directly together, into the gas tank? Based on the aforementioned, I'm assuming this it's a 4-stroke in this video (and not a 2-stroke) , as the oil inlet appears to be visible at the lower left corner of the engine, at the 0:56 min. mark - while you also state at the 2:08 min. mark thereof, that someone (may have) accidentally put a 2-stroke mix into the fuel tank of such? But if I'm wrong in my understanding and the mower in this video is a 2-stroke, then I would again, if there’s any way that you could specifically identify the "diaphragm" w/in the context of such, as already previously referenced? And finally, at the 3:27 min. mark, you reference the "PVC tube". What does “PVC” stand for? I sincerely apologize for my ignorance in these regards, and for my query in these respects being so long winded, which is unfortunately due to the fact that I have a disability w/processing information, and so this is how I learn. That being said, thank you so much, once again, and also again, in advance, for your patience and understanding, as well as for your clarifications and help.
What a fantastic question! I had a friend have a swollen inlet-needle, it ran fine but just leaked. I haven’t experienced either symptoms, but I wouldn’t rule it out!
Any suggestions for a surging Briggs and Stratton 17hp OHV with a newly replaced crank case gasket, head gasket, new intake gasket, new air filter, valves cleaned and lapped, verified spark, 100 PSI compression? She starts right up, but it surges and has some smoke coming out the exhaust. The engine internally is super clean, cross-hatching on cylinder walls, compression relief still solid. I'm at a bit of a loss on the surge issue and smoke. Valve gaps checked and rechecked. .004" intake and .006" exhaust, set about 1/4" past TDC on exhaust stroke.
Hey, I would suggest it’s likely two seperate symptoms - surging and smoking. Surging: blocked fuel filter, faulty fuel pump, damaged lines, blocked carb jets, improperly tuned carburetor, leaking intake manifold, leaking head gasket. Incorrectly set governor (too fast) causes surging too. The smoke could be: overfilled crankcase, blocked pcv valve, worn bore, leaking valve seals, incorrectly fitted or sealing head gasket. Double check your work and the above points :) a leak down test will be useful in this instance!
@@VintageEngineRepairs Believe it or not - the governor spring was just a bit over stretched. I tightened it up today, and the surging stopped and I really have not noticed much smoke. Runs very smoothly now.
Good video but my mower is still surging. New carburettor, new gaskets, new air filter,. clear fuel filter and hose, enlarged the jet thingy. No diaphragm. Can't find the fuel tank vent but still surges with the cap off. Was fine last year but foolishly left petrol in the tank over winter. Can it be something inside the engine?
@@VintageEngineRepairs thanks for the reply but they're new. I'm so baffled. I'm thinking could the inside of the fuel hose narrowed a little, even though I can still see light through it with a bit of manipulation
I'm working in a honda lawn mower that surges up and down and noticed several things mentioned from your video. I cleaned he carb really good with carb cleaner but the issue still persist. It will start with one pull but not smoothly. it surges up and down still has uneven idle. Things that are red flags to me is the Honda carb is missing several gaskets for instance the one by the air intake and the one by the manifold. They both rotted and deteriorated. Next i notice there appears to be some grime or dirt at the bottom of the tank. I haven't cleaned out and blew out the fuel line. The mower has fresh gas, new plug, new filter. From what i know the prior owner stored it outdoors and looks like it was only covered sometimes not all the time and was exposed to rain and snow in the northeast in the states. any recommendations what to do next to get the mower running smoothly again?
I have same carb on my lawnmower, issue is that after using the machine about 30 minutes, petrol pouring out from air intake of carb. I have replaced the carb same model and type but same problem, petrol pouring out from air intake.
You sure it’s petrol not oil? If it is, it could be spit back from a valve not sealing or a carb needle not seating. It could also be blow by causing pressure in the crank spitting oil into the AF?
I had one this spring that kept surging despite trying 3 different carburetors. Plastic carb and same basic model Briggs. After I reluctantly sent it out surging, it occurred to me that the plastic intake tube may have been cracked. Have you ever replaced a cracked plastic intake?
Just a quick Question.. As you started off with the 0.35mm drill bit to begin, what size drill bit did you use for the final drilling of the jet before assembling the carb back together? Many thanks.
9:00 - You see those drops coming back out. You don't know how close you came to being permanently blinded by highly penetrating solvent. I had some of the tiniest droplets of carb cleaner hit my eye doing that, and within seconds... like less than 20... I had gone blind. It took me 4 years to line up surgery to fix them. Either wear safety glasses, or better... throw away all pressurized carb cleaners and solvents in your shop and never ever buy them again. It's not worth it. They are the most dangerous things in your shop. What did the world look like being blind? It looked like always looking through a frosted car window on a winter day. You could see out, sort of, but you really couldn't see anything at all... and you dare not drive like that or you'd run into something in no short order Everything blurred together and was very bright. I couldn't count the fingers on my hand, or see the items on a grocery shelf.
That’s terrible, sorry to hear it, I have had carb cleaner in my eyes many times, it burns for a few seconds and then goes, but we don’t have chlorine in ours out here like you do in the states! It amazes me that you guys have that in cans like it safe…
@@VintageEngineRepairs I don't think it's any chlorine, I've been in heavily chlorinated pools... I think it's the Acetone, Toluene, and Methanol. Your eyes are very permeable; acetone will go through the smallest cracks and strip the paint of things. H280 - Contains gas under pressure; may explode if heated H301+H311 - Toxic if swallowed or in contact with skin H315 - Causes skin irritation H319 - Causes serious eye irritation H336 - May cause drowsiness or dizziness H361 - Suspected of damaging fertility or the unborn child H370 - Causes damage to organs H373 - May cause damage to organs through prolonged or repeated exposure
Those are some of the worst carburetors I have seen and I have constant problems with them. I always have to clean them and I always find water in them.
Hey, Yes, but as mentioned in my video, they’ll very likely not work. Chinese clone carburetors are notoriously bad. It’s quicker and less frustrating to throw your money right in the bin. Also, I’m teaching people how to repair, not parts swap.
Great video. Went through it with you step by step. Mower was surging constantly and cutting off at times. Runs like it's brand new now. I tested it after every step so it took slightly longer than the video but still less than an hour.
