How to Adjust Valves on Briggs & Stratton Engine, THE CORRECT WAY!

our mike here today i'm going to show you how to adjust the valve clearances on a brigade briggs and stratton motor here i've got a breaks of strat out of a john deere la 145 this is a two cylinder motor 22 horse made for john deere but they're all these briggs strattons they're pretty much the same the same process applies whether you've got a single cylinder or a two cylinder like this one so the first step you want to do you want to remove the spark plugs so to do that this is just a 5 8 they're all pretty much 5 8 socket pull her out and on a two cylinder motor you're going to want to pull out both of these spark plugs that way you have no compression and that way we can turn the motor easily next step you want to remove the valve cover once you have the spark plugs out these are just a 3 8 inch bolts i'm a little impatient so i like using my uh electric screwdriver here pull them out they shouldn't have that much space on them these four guys and we'll see what's going on here all right now we got the valve cover off we get to the fun part see what's underneath there so just to give you an overview of what's happening underneath this valve cover is you'll see the push rods right here so you have two push rods what those do those ride on the crankshaft and as the crankshaft turns the push rods push up on this rocker this is a valve rocker and it pushes up and then it pushes down on the valve on the other side so this is the valve valve spring so as the motor turns the crankshaft is pushing on these push rods and then it push downs on the rocker and the rocker pushes back on the valve so this is the exhaust this is the intake so right now it's pushing down and it's opening that exhaust valve allowing the exhaust to escape out of the cylinder and it comes back up and then next it lets the intake valve on so this is sucking air in and fuel creates compression boom and then back out the exhaust so now what we want to do is that we want to adjust the valves when they're at top dead center meaning that piston is at the very top of the compression stroke pushed all the way out so to do that get a long skinny screwdriver keep her clean and then just slide it in the spark plug hole and then you're going to twist the crankshaft so essentially twist the fan on top of the motor and you want to feel where that piston pushes all the way out so you're to where your screwdriver is pushed out as far as it'll go what it is and then you'll feel it start sliding back down so you push it out all right so this is as far as it goes now let's feel it oh those are tight you can't adjust that so the reason that is tight is because that's on the intake stroke meaning it's pushing those valves down allowing fuel and uh air to go into the motor so you can't adjust the valves there so we need it on the compression stroke so let's twist it again so it goes to the bottom the cylinder goes all the way back up top so there we go cylinders up top hey we are at top dead center of the compression stroke so it's creating compression inside that cylinder and in order to do that it's got both these valves shut and while they're shut that is when we check the valve clearance next step we want to adjust the actual valve now on these briggs stratton motors pretty much all of them out of the big box stores on your regular lawn mowers this dual and single cylinders they all adjust to about zero zero point zero zero five inch uh the book says point zero zero four three point zero zero seven i just got .005 on each side now in order to do that we're adjusting this clearance here as you can see that one's awfully loose you want to first loosen up the lock nut on there so to do that you take a half inch box in wrench loosen it up that one's way loose and then you take a t40 bit now to save you a ton of time and cursing i like to put it on a regular screwdriver and put the with the head on on the end that way it gives you a lot more control so what you're doing here is you're tightening it down until it tight but not too tight this one's way loose so there it's too tight you can't move it you just want to back it off just a bit where it's there we go and it's you just gotta play around with it a bit so that that feels pretty good where it slides in you can feel that restriction there and then you want to hold that t40 tight as you lock down the lock wrench don't let her move or else this whole process gets jacked up so there we go all right all right with that your valves are adjusted go ahead and repeat the process on your exhaust valve and the other cylinder i'm also going to post a video on a common failure point on these aluminum push rods that cause a lot of issues on these models it's a failure point that you've got to be aware of when you're looking at these things so with that i'm out i hope you enjoyed it please subscribe

Channel: Mower Mike

Views: 167,919

Keywords: John Deere, Valve, Valve clearance, Clearance, Valve adjustment, Adjustment

Id: 0jihPoBM-Ow

Length: 5min 42sec (342 seconds)

Published: Sat May 15 2021