Can We Fix It? Engine Exploded! Rebuild Restoration

so foreign [Applause] well welcome to another lawnmower repair video this is a westwood s 1200 which is very similar to the very common t1200 it has the same engine same gearbox and even the same deck it just has a slightly different design different bodywork and a few variances to do with the pto and under the bonnet things like different fuel tanks so not really major things it just seems more basic so this engine here is apparently seized i did try and pull it over by hand and yeah it doesn't seem to turn over what we're going to do is remove the engine take the sump off and obviously inspect it see exactly what's going on in there and hopefully fix it up and get it running again the deck has seen much better day so i'll probably just take that off and keep parts from it to rebuild onto another deck shell in the future here's a closer view of the deck it's just rotting away all right first step is to remove the oil drain plug not too sure if it's actually going to go in the pot looks like it is just about going in a bit awkward not much space there we go so we'll check and see if there's any metal shavings in there you can see there is a bit of discoloring now looks more like water though when the water gets into the oil it goes all creamy now because the deck has been removed i can now turn the engine backwards before i was using the pull cord but because i can turn it backwards now you can see that it does turn a bit too freely and then there we go we're locked again now if we go back in the opposite direction it will turn freely and then we're locked [Music] those pulleys can be quite stubborn the air hammer is a great tool to use anyway next thing to do is to remove the engine from the chassis there's four bolts there is the throttle cable several wires and then it should just lift straight out of there once i've removed it i'll also give it a good clean you can see there's quite a bit of dust and dirt building up on it [Music] so so just put some towels under there ready definitely too much that comes out but there's always going to be a bit of residue that's interesting so i wonder if that's given where that's detached and i don't know maybe the piston pin came out we'll find out in a second a piece of the connecting rod sort of the um the side of the conrod and then we have some more pieces up here it's actually surprising that the oil looked as clean as it did so we have the connecting rod which leads to nowhere but it looks like it hasn't really broken into too many pieces so we're not gonna have damage from shrapnel uh there is a little piece just on there but i'm really hoping there isn't too much damage to the other parts the first part to inspect is the oil slinger which is also the governor looks like it's okay next we have the camshaft it's always easier to align the timing marks when you remove the camshaft so can't quite get them lined up because of the piston which is jamming that's close enough we just had to tap it fall down this one at the front here will be our exhaust one which actually is stuck there we go may well be slightly bent they usually just fall down like the intake one did wow well i've just discovered why it was so hard to remove that exhaust tap it it's because this seems to be the other half of the connecting rod embedded into the crankcase look at that that is violent this obviously opens up quite a few questions was the engine running too fast did it not have enough oil that's strange because we drained plenty of oil i had enough in it did somebody refill the oil after it blew up or is there just fatigue was the fatigue in one of the parts like the conrod did it have a hairline fracture was it a factory defect so many different possibilities but this is definitely one of those more unusual ones the next thing to remove is the cylinder head i want to inspect the top of the piston try and remove the piston and see if we can see what's been going on up there quite a few things to remove here the fuel tank bracket the muffler and the fuel hose brackets as well the moment of truth okay so nothing out of the ordinary here this is all looking okay and normal so i'm just going to try and remove that piston the piston doesn't seem seized and the connecting rod didn't seem seized to the crankshaft and there we have it yep so you can see the piston pin just slides out which it certainly shouldn't do it's because the retaining clip has been it's fallen out as i showed you earlier but it looks like everything else here is fine there's no scoring on the pin no aluminium has transferred hasn't smeared onto here so the issue is certainly further down you see that's where there is a break and the cylinder ball is absolutely fine until you get to here there's a great big gouge that's probably been caused by the clip if the clip came loose and then got wedged in between the piston skirt and the cylinder ball it would have jammed everything up so is that the reason why the connection rod snaps it's been very interesting to look in here because there should be a piece of conrod but it shouldn't be a piece of conrod but i think there is going to be a piece sticking into here the valves are ever so slightly open there's no camshaft so it must be the conrod holding them open that is really interesting just look at how it's blasted through here it's completely mangled this spring for the exhaust valve and it's even removed the retainer from the intake valve the retainer is still in there but as you can see the spring is no longer attached the most interesting conrod snap i've ever seen i think uh because it usually comes through the side so now i need to think about what to do for the best obviously i can't use this crank case it's just far too damaged if it just comes through the side here it's usually the other side then it could just be jb welded up but clearly this is much more serious it's just damaged everything um i think even yeah these valves that valve especially is going to be uh beyond repair along with the valve spring so if i get a good used engine or maybe just a used engine then i might be able to establish some parts of it so the valves obviously everything to do with the valve the springs the retainers and also if we can get the crank case as well but the thing is it has to have a good bore doesn't want to be worn and it doesn't want to have any other damage [Music] it shared the keyway no surprise there that is everything i need off the original engine i actually need to make sure this crankshaft is good so when i remove the final piece of the conrod i know what the condition is like because i think with the exception of this piece everything looks really good that looks really good that's exactly what i was hoping for sometimes the conrod smears the other menu around here which is a fixable issue you can melt it off with acid and for anybody wondering this is what the end of the connecting rod looks like pretty good there's your little scratch but nothing substantial so yeah it's looking highly likely the issue was not at this end and it didn't really look to be really the top of the piston either it's not the pistons seizing the ball so really the only thing which is obvious here is that clip which is unusual i need to replace the crank case so i've just been looking around in my scrap mower parts and i have found this old engine which seems to be okay it turns over by hand that doesn't show as if the bore is any good or if the valves are good but what i'm gonna do is strip it down and then we can inspect everything and see if this is worth using obviously it's really grimy the paint's flaking and it's covered in aluminium oxide but it doesn't really matter too much because i can clean this up quite nicely and return it to a like new condition i'm only really concerned about the internals of the crank case i'm going to look inside the cylinder ball so as you can see there is all in here it looks like it's coming through the exhaust valve because that is partially open but that's fine that's because the engine has been tipped over the side of the bore looks okay it is quite hard to see on camera i've removed more parts from the engine including the sub and now we can see all of the internal parts which are covered in this disgusting sludge a combination of old oil and water this engine was actually left outside i don't actually know why the engine was abandoned in the first place we'll probably find out in a minute or two but yeah i can now remove these parts then we can properly inspect the crankcase here's a look at the sump just as disgusting but we probably won't even need the sump firstly there is the oil slinger and governor seems to work then we have the camshaft it's quite hard to see where the timing marks are it's a bit rusty but i can't see any damage i've got the valve tappets ideally these should be changed if you buy a new camshaft from briggs and stratton they will probably send you new topics as well [Music] great doesn't look too bad it's probably a good piston with the piston removed you can really see what the ball looks like where the piston actually travels it looks really good but at the bottom there is some rust which really is not unexpected since it's been outside and that area has been filled with water so it's hopefully going to be fine because when i home the engine it should remove all of that and really clean it up i'm also going to measure the board just to make sure that it is in spec it looks like it probably will be i can't see any ridges there's no rough spots there's no lip at the top so it's looking good looking promising it looks nice and clean in there so i'm just going to remove the valves and then i'm going to put it into a hot wash so i can clean the crankcase up it probably won't clean up perfectly but it'll be a good start as the valves out there was only one casualty when stripping this engine down it was just here where the carburetor attaches to the bolt was sheared so i'll try and get that out later first of all though a deep clean to do this i'm using the hot washer i'm going to set it to about 80 degrees celsius and we'll see what it can do to it so that's removed most of the grease just leaves behind the aluminium oxide which can be wire brushed but as it's gonna be painted anyway i think that'll probably take care of it so the next thing to do before i clean this again is to hone the ball let's just take a look at that this will need a thorough clean but you can see i've got the cross hatching on the cylinder wall it's always hard to tell how well things show up on camera but hopefully you can see that it's really cleaned up and also removed the rust okay now i need to take a few measurements just to make sure the bore is within spec now the range we're looking for is 87.28 and 87.31 and this one is 87.29 so that is fine i will continue to take some more measurements but i did do some earlier just to ensure this was actually viable but yes i'm sure it is uh a perfectly good ball that one is 87.31 but this isn't 100 accurate and that is also within spec before i give the crank case one more clean there is one more thing i need to do and that is to lap in the valves the reason why is because the valve lapping paste or compound is very abrasive and if you don't clean this out properly you can actually wear parts that you didn't intend to wear out like the valve stem so yeah this needs to be done before the final clean [Music] [Music] [Music] so that's the crankcase and some pre-painted i've also cleaned up all these other internal parts so they're almost ready to be refitted except for the piston i'm going to change the connecting rod this one doesn't look too bad but i just don't know the history it looks like it has done quite a few hours so a connecting rod is cheap i'm going to put a new one on to there and i'm also going to change the piston rings i fixed the issue just here with the sheared bolt and i'm also going to change the sail for the governor shaft i'm actually going to change the governor shaft for the one in the existing engine just because it looks better and i have the full gasket reboot kit part number 494 241 there it is so everything i need here except for carburetor parts is included we've got the head gasket we've got the crankcase gaskets this is the seal for the dipstick tube exhaust gasket parts for the air intake intake gasket just here oil seals everything next onto the piston so that is the original this is the new connecting rod they look very similar as you'd expect but we do have a bit of a design change here there's no more locking tabs and it includes two different size bolts with different torque settings which do have to be talked in the correct order so yeah end cap on the cam side is the most important thing to remember along with the notch facing the flywheel that's how it is from model 28 engine so i'm going to get that changed over and i'm just going to change the piston rings as well here are the new old stock piston rings and there is the part number so i'll just show you these it's amazing how the boxes have changed the new ones just fall to pieces you can see the difference between them this one is nice and rigid this one is just collapsing when i picked it up to get out of the parts store everything just fell out the bottom this one's much more solid i could understand wanting to use less materials for environmental reasons and obviously costs uh but yeah if you're gonna do that maybe tape it i think a bit of tape would have been fine anyways enough of reviewing the boxes so we have the piston ring installation instructions and the new piston rings just here i will be keeping this conrod for a future project probably a well it run video because it really isn't too bad it comes to 45 thou which is way out of spec so let's put a new ring in size 12 foul i've seen better but that is perfectly within spec i'm going to change them all over now and rebuild the engine just the complete reverse of taking it apart so it's going to be fairly self-explanatory and for anybody else who is maybe installing the same conrod but didn't get this instruction for whatever reason i'm sure you will do um yes there is the information and if it is a horizontal shaft engine you also have the oil dipper as well [Music] this you [Applause] that's all the internal has done and i've checked the valve clearances and they're all fine so now moving on to the head the head actually is quite good fairly clean got a bit of carbon buildup but i can soon clean that up put it in the sandblaster and that will really uh remove all the carbon and then be ready to be fitted so do i'm at the stage to refit the car brush above just taking a look inside and it doesn't look that clean so i'm just going to go through it clean it all out with carb breast cleaner and then reassemble it and put it back onto the engine and hopefully everything will be fine as you can see it's got quite a bit of residue i think it might be a bit of rust and everything is very gummy so as i said strip it down clean it up and rebuild it you [Applause] foreign so do [Music] so okay so it's as far as need to go before i put it back into the machine so let's get it off the workbench and put it back into the mower so so so so so [Music] [Music] [Music] so so [Music] [Music] [Music] [Music] [Music] [Music] you

Channel: Machinery Restorer

Views: 101,375

Rating: 4.948998 out of 5

Keywords: restoration, tool restoration, hand tool restoration, mechanics, mechanic restoration, hand tool, mechanical, machinery restorer, hand tools, engine rebuild, fix, repair, briggs stratton

Id: _3WUWft8ywE

Length: 48min 11sec (2891 seconds)

Published: Fri Jun 11 2021