How to Fix Lawn mower Engine Surging on Briggs & Stratton Lawnmower Engine!

that really annoying engine surge i'm going to explain why that's happening now hello and welcome and in this video i'm going to go through some of the most common causes why this type of briggs and stratton engine can have that surging problem and general running issues and this is really a skip over of the reasons so we can get to the point a little quicker and i've provided supporting links below if you need to go in and rectify any of these problems in detail and before i go any further i'd like to give a shout out to a man who knows the diagnostics and repair of these engines and many many others inside out and has had years of experience with them and that is mixed mowers you'll find his content absolutely brilliant he's a hands-on guy practical and he knows his stuff please do go and take a look at his channel you're definitely gonna benefit there i've put a link below in the description that will take you straight to him fantastic now let's get started with our briggs engine okay so what i've found with these types of engines is that whenever there's an interruption of the correct fuel to air mixture then you're gonna get a sound like this this surging sound and there's several popular reasons that i've found why this does occur okay so the first thing i would do if i was having any kind of running problems with this type of engine is check the air filter the air filters on these types of engines are made of a sponge type material and they can become quite oily and sticky and hold on to the debris as it comes in through to the engine and that's a good thing to stop the debris going into the engine but they really do get clogged and they really do need to be regularly cleaned if they get too clogged it's going to restrict the airflow going into the engine and cause running problems the good news is that these can easily be cleaned and replaced by using some soap and water or some gasoline other than that if it is damaged and needs replacing then they are relatively inexpensive and because they're reusable they do last a long time and i've put a link down in the description below that will take you directly to this type of air filter the next thing i would check is something i would do whilst i've got the air filter off it's not necessarily something i'd do in this order but as we got the air filter off take a look at the governor springs these two springs usually exist on top of here and operate as a pair and if either of these are missing this can give running and starting issues because the throttle won't be working correctly so it's always worth just making sure that these two are present again if either of these two are damaged or missing they are readily available online and should you need them there is a link in the description that will take you to them okay so the next one is a big one it's something i see year after year and that is stale fuel fuel that's been in the fuel tank for too long particularly over winter when the lawnmower has been stored fuel is something that does go bad over time and less combustible so i always make a habit before i winterize my mower to drain the fuel properly out of the mower completely draining the fuel also instigates a little bit of a fuel tank cleanse because when the fuel is coming out sometimes the debris that's accumulated inside the tank over the summer comes out with it and that's also important to make sure that the bottom of the fuel tank is nice and clean so no dirt goes inside the carburetor and blocks up those little fuel holes and causes this type of running issue so always make sure that your fuel is no more than six weeks old and whilst it is somewhat controversial this is a generally accepted time of fuel been at its best okay so another thing that i've personally come across that can cause this type of issue is the prima bulb believe it or not have a check to make sure there is no little tiny holes in the primer bulb sometimes holes can appear through damage for whatever reason and at this point it can draw in air and it can stop the mower from operating correctly as well as that there's going to be starting issues if the primer bulbs of course damage because we won't have the air pressure inside there the suction pressure to bring up the fuel in the first place and prime the carburetor system so just check the primable but if it needs replacing there's no way around this okay so that brings me on to my next point and this is something that these engines are famous for and that is the diaphragms between the carburetor and the fuel tank this diaphragm is like a fuel pump and a one-way valve system to allow this type of carburetor to function and what can happen these diaphragms can sometimes degrade over time and just become past their best and it can give that famous surging sound on this type of engine if you haven't changed the diaphragm on this and everything's okay with your machine then fine but if you do get this type of surging problem it's likely to be this diaphragm if you need to replace these i do have a link in the description that shows you step by step how to replace these and also how to get access to the diaphragm kit as well the diaphragm kits themselves are quite inexpensive and it's well worth changing them the main cost of this is actually the labor that the lawnmower dealers would charge to fit one so if you could do it yourself then you're gonna save yourself money we can appreciate now at this point how important it was to take the time removing the carburetor when we look inside the top of the fuel tank here in this small compartment where the short pickup pipe feeds into you can see there when i take this small screwdriver and have a little scrape that there's so much dirt and crud inside there so we need to give this whole fuel tank a good clean and i like to add some soap and then wash it and rinse it to remove any residues of fuel before i blow it out with the airline now it's not really an overly common problem but it's well worth a check this special machined area where the carburetor sits it needs to be completely flat from one edge to the other and whilst it's more common for the carburetor to distort being made of a plastic type material particularly in the areas between the securing bolts where there's less direct pressure holding this area down there can be a slight gap appear in places like this where air can be drawn in where it shouldn't and fuel can escape or both and this can obviously disrupt the workings of the carburetor this is just a wood chisel that has a nice straight edge and i just hold it from one side to the other and take a look down and see if there's a gap there does the metal that exists there touch the straight edge as it should do this one is actually okay it only takes a few minutes to do this and it's well worth doing so if you've got your carburetor and fuel tank stripped down this far i have in the past had a small number of these tanks that are distorted and my remedy for them was to buy new tanks i do know some people that i've put these on a straight edge with some wet and dry sandpaper and sanded them back straight again and they said they've had success with that i personally have never done this and i'm definitely not saying it's wrong it's just i can't tell you the outcome from my own experience and it's worth checking the carburetor for distortions as well so i'll get the straight edge and run it across the bottom face that meets the fuel tank and make sure that the plastic is touching the straight edge all the way across particularly from bolt hole to bolt hole where it's susceptible to leaks now something else i've come across in the past which isn't that common but is often overlooked that is the o-ring seal that seals the carburetor onto the intake tube onto the engine again this isn't too common but sometimes these can be missing they can be damaged flattened in some way or just pulled off slightly and they're not sealing and again this can be overlooked so it's well worth just taking a check on this you can actually remove these and clean them and make sure that there's no damage on them if there is any damage whatsoever you can buy these for just a few pounds and it's well worth making sure that they're fitted correctly and again i've got a video link in the description below that shows you me removing one of these cleaning it and then putting it back together again it's really simple but if you want to take a look at it please do and if you need a new one of these that's also in the link below and so that brings me on nicely to the intake tube itself in the past i have had problems with these tubes these are also something that's overlooked because when we do have running issues with these types of carburetor generally we go straight to the diaphragm i've overlooked this issue several times in the past and i now always make a habit of checking this every time i repair one of these carburetors and the most thorough way to check this is to remove the recoil housing and take a look right across the length of the intake tube i've had these crack little tiny cracks sometimes where they leak in air here in an unnatural place and that messes around with the fuel to air ratio and so the engine just will not run right also i've had these bolts come loose allowing air to come in below where it connects to the engine and again that's going to cause running issues so it's well worth taking a good look at this and make sure it's in good order and if there is any cracks or damage then you can easily get hold of one of these they're readily available and again there's a link below in the description that will take you directly to one okay so i hope that's helped and remember this is just the main causes that i've found personally with this type of engine there are many reasons why any engine not least this engine could fail but i'm just giving you here the main culprits the main problems that i have found in my own opinion and so now i want to thank you so much for watching this video please give me a like and subscribe if you haven't done already thank you for watching [Music] you

Channel: TheRepairSpecialist

Views: 67,679

Keywords: craig kirkman, the repair specialist, TRS, briggs & stratton, briggs and stratton, camshaft, craftsman, fix, flywheel, keyway lawn mower, mower, plastic camshaft, plastic cam, quantum engine, quantum, shear key, small engine, timing, troubleshooting, valve timing, valve, will not run, will not start, 126m02-6863-f1, 126m02, 691449, 492830, 498275, 498817, lawn mower wont start, lawn mower wont stay running, lawn mower wont pull

Id: U709YgVv8jQ

Length: 9min 57sec (597 seconds)

Published: Sun May 23 2021