hi i'm matt from espares now if you've had problems starting your petrol lawnmower you'll know just how frustrating that can be I'm going to run through some of the basic checks that we need to go through to make sure that your mower starts first time every time now I've got a qualcast classic petrol 35s but these checks will be applicable for any type of qualcast indeed any type of petrol lawnmower let's start with fuel it's a standard four-stroke engine takes ordinary unleaded petrol now I think about petrol is it degrades over time it goes off so if you've left petrol in your mower over the winter best thing to do is to drain that off first and put some fresh petrol in there two things I want to drain and drain the main fuel reservoir just by uncoupling the fuel line there and drain that off into a bowl and then you can see on the carburetor here there's a little release valve there that'll just drain the fuel off the carburetor as well and then make sure we've got fresh petrol in let's check the oil the dipstick on this qualcast is at the back here just give that a white and pop it back in I think it looks alright yeah that's just over half full so that's fine if you do need to top-up then top up at the front there make sure you're using proper lawnmower engine oil obviously if yours is a two-stroke then use two-stroke oil and that gets mixed directly into your fuel so spark plug next it's a standard 14 mil lawnmower spark plug and I'm using a 21 mil socket which is specifically for spark plugs it's going to make sure I don't damage the porcelain or the top of the engine I'll take that out now spark plugs do have a limited life it's typically around about 150 hours for this type of spark plug and as you can see there's a fair bit of sitting for a bit of carbon on the electrodes there it's not actually in bad Nick I think I'll just clean that up with a wire brush and get a bit of fine sandpaper between the two electrodes just make sure it's all nice and clean I'm actually just going to put a brand new one in here make sure you're getting the right spark plug for your particular mower they're available for all makes and models on the espares website and then just tighten that up not too tight to make sure we don't overdo it there we go we're going to get a good spark every time now so a few things I just want to check before I fire it up just the cables the belts and the gears if I take off the belt housing cover here that's just held into place by these four hex head screws you could use a Torx bit in there and if I engage the rear roller just make sure that that's torsion in the belt when it's in the on position that's fine likewise if I engage the cutting disc yeah that's putting some torsion in that belt fine just have a look at the belts make sure they're not fraying there's no sign of damage or where they're fine and these gears I don't know if you can see in there there are actually three nylon gears they can break quite easily and you can see a colleague of mine actually replacing those in another video but that all looks fine now if I just check the throttle so in a fully off position you should be able to see that just cuts the power to the spark plug that's fine and then as I open the throttle you should be able to see it's just opening the carburetor there if that needs any adjustment this little screw here just changes the position at which it opens the ok let's get it started push the throttle all the way back all the way open I'm not going to give it any choke because it's quite warm we're inside obviously this on a cold day then you want to give it a bit of choke it's probably worth showing you actually how the choke works I take the air filter off here you can see that the air filter and the choke restricts or chokes the flow of air going into the carb just gives us a much more petrol rich mixture going in which is what we need on a cold day because the air doesn't mix with the factual quite so well ok let's give it a go it's a bit of an awkward height for me here on the table but it's if we can do it first time now if yours doesn't start the problem is probably going to be in the carburetor let's take a closer look so before I open up the carb I just want to disconnect my fuel line and drain the fuel in the tank down into my cam about to spill a little bit so with my fuel line out of the way and if I just get the air filter out of the way as well I just need to drain the remaining fuel which is sat in the car I can do it on this release valve here now it's going to try and get as much paper towel under there as possible and just soak that up there we go that's empty nicely okay let's just open the nut on the bottom the car breath and out let's see what we've got inside so I undo the bottom screw the float chamber comes away there just pop those to the other side and here we have the float itself I'm just going to push through this hinge pin and then I can pull a hold of the float mechanism away so the two things I'm concerned about art this float piston that sits on top of the float there and rises and falls with it and that lets fuel into the float chamber now the bottom screw that we took out as fuel jets in here we're going to need to clean both of these things thoroughly for these jets just going to run a piece of wire through there and the one through the middle just to make sure that we've got no dope Gabriel net and give the piston itself a good clean with compressed air or you can get a specialist carburetor cleaner it's also a good idea to spray that cleaner or the compressed air around the rest of the carburetor just check the the gasket seal as well this one's in perfectly good condition but if that's looking a bit of a mess than it probably a good idea to replace that as well okay let's just put the carburetor back together you can see on the float chamber there is a shallow end and a deep end make sure you get the shallow end where the hinge of the float goes and then just put the screw back in don't forget to reconnect the fuel line and of course you put the air filter back on there we go top up with fresh fuel and we're ready to go there we go that should deal with most of the problems associated with getting your petrol lawnmower to start spare parts for qualcast and lots of other makes of mower are available on the espares website thanks for watching you