Lawn Tractor Engine Running Rough, Missing, Popping, Sputtering / Briggs Engine - FIXED

hey guys welcome back so today I brought home a pool on and this one well like everything else doesn't run it is a powered by a 17 and a half horse Briggs & Stratton and has a 42 inch deck now I don't know much about it the guy I bought it from actually got it at an auction and he thought given its appearance that this would be an easy score but he could not get it running so that's how I got it anyway he did turn it over for me so I think I have a fair idea what's going on but just to show you the engine does turn it has pretty good compression so from that point of view I think the engine is solid but there is definitely something keeping this thing from starting so let me get you set up in a stand I just turn it over and kind of show you what it's doing so as you could see it did kind of turn over and I can hear it huffing and puffing for lack of a better word and you know that tells me it has spark so the only thing we're left with is fuel and timing and I can smell the fuel so I don't think fuel was the problem it's most likely timing so I'm gonna show you how to check the timing without removing the flywheel of course the timing was off you're gonna have to pull the flywheel but you know why do that if you don't have to so I'm just going to get this shroud off so you can see better kind of the position of the flywheel versus the magnet and the ignition coil just two bolts in the front two bolts in the back and then one screw right here that is a pretty clean looking engine so in order to check timing yeah I can pull the flywheel nut and take a look another way to is just to pull the spark plug flying top dead center and just locate where the magnet is on the flywheel versus the ignition coil so that's what I want to do first it's a bit easier because if it's not a timing issue that saves a bit of time okay so this is top dead center you can see the magnet position just clearing the coil that's when it's gonna spark so this actually looks like it's timed pretty well so I'm not gonna pull this and check the key because I actually think it's okay I'm gonna get this valve cover off and see what's going on into there spark plug on the right is the one I pulled out I mean that thing just looks to be a complete mess so I'm kind of suspicious of that plug I'm gonna hook it up and just watch the spark and make sure it's working actually look at that it's touching the electrode there's no way that's kind of spark properly so jeez it could be as simple as that I've got this other plug here I believe it's the same type I'm gonna throw this one and see if it starts all right well it is running better but seeing a spark plug the way that it was is making me a little bit more concerned about the top-end you know potentially a blown head gasket valve issue it's making some weird noises in here so I'm gonna get the valve cover off and see if I can't see anything Wow that is way out of spec look at that so why would that be like that the rod looks okay I see the problem now that that little guy supposed to be on there like that yeah and that makes the clearance a lot tighter okay I feel better about that now so somehow this rotator popped out and then of course gave excessive clearance and yeah now we've got the issue that we have so is it as simple as this I don't know but I'm gonna put this back on I reset the clearance and give it another try so one thing to note hopefully you can see how this stud in here and I went to loosen this here you can see that stud is loose so that's probably what led to the excessive clearance which allowed the rotator to pop out and all this trouble so I'm gonna I don't know the torque specs offhand so I'm just gonna Snug this up for now reset the clearance to about four or five thousandths temporarily throw the cover back on and just see if things are running any better okay let's try this again very nice I was a little nervous I didn't think it would be that easy I thought it was going to be something wrong with the head but I mean I guess there was something wrong with the head it just was not nearly as severe as I thought it could have been a lot worse actually if I'd kept running it the pushrod was kind of slapping around in there I could hear something banging around I thought it might actually be in the kind of in the crank the lower end but yeah we got lucky on this one the rotator fell off due to the stud coming out and was just floating around in there so I'm gonna look up the proper specs for those studs and proper clearance and I'll turn you back on once I got those numbers and I want to torque everything properly you probably put some thread Locker on those studs so that doesn't happen again anyway turn you back on in a second I didn't have much luck finding the exact torque specs for this engine but did find a lot of specs for Briggs in general and from what I can tell rocker covers about 60 inch pounds the studs are about a hundred so that's we're gonna go with okay that's way too much but I'm gonna put threadlocker on both of these to hopefully prevent this from happening again alright that's eighty hundred hundred it is that did find the specs for the valves intake is supposed to be between three and five thousand so I'm gonna go with four that's pretty good okay actually got this wrong I wasn't paying attention so the valve that was loose was not the intake who was actually the exhaust and kind of the giveaway for this was the fact that this bottom one is an aluminum push rod you know I saw this going in here and just assumed it was this valve but it actually is a channel that goes down to here so the intake is the bottom that one was fine the exhaust was the issue so I do need to reset this actually to six thousandths and this one is should be four okay so I clean the surfaces up made them nice and smooth degreased it and I've got some gasket maker on here now I did double check just to make sure that wasn't actually supposed to be a gasket here and for this engine they just recommend our TV so that's what I'm going with okay so I'm gonna let that set up for about an hour and then just torque it down to 60-inch pads okay this white filter I think it's a paper-based filter which is not really recommended for gravity-fed systems so I went through a red one on there and put a fuel shutoff as well all right not too bad this mower it drives great runs great cuts great it even turns great the turning radius on it's fantastic so I like this mower a lot I mean it is a simple you know bare-bones I guess lawn tractor but you know I'm actually quite happy with it so I might keep this one anyway hope this video helps someone thanks for watching she wanted to try it out runs well

Channel: James Condon

Views: 255,828

Keywords: 31C707, 31C707-3346, 31C707-3346-G1, 960160024, Briggs and Stratton, Fix, PXT175G42, Poulan XT, Poulan, Repair, Rocker Arm Stud, Rocker Arm, Rotator Cap, Small Engine, Stud, Timing, Troubleshooting, Valve Adjustment

Id: zpFdvobEWzg

Length: 18min 39sec (1119 seconds)

Published: Thu Jun 25 2020