Briggs & Stratton Carburettor Diaphragm/Gasket Kit. 795083

My cheapo Mountfield lawn mower was starting to run very rough. It started o.k., but then the engine "hunted" - would not idle properly, with clouds of black smoke periodically and trying to stall when cutting. Seemed like the governor was at fault! I pulled the spark plug - it was covered in black soot - running too rich? The air filter was clean and clear, I ran some carb. cleaner through the throat of the carb whilst running up the engine by pulling the governor spring gently. Still no improvement. The governor springs were all clean and moved freely - as did the governor arm by the fan (under the engine shroud). I was sceptical that a replacemnt diaphragm would cure this - but for the price, it was worth a go. It is best to remove the fuel tank from the mower first, with the carb. still attached. Just two bolts to undo, a rubber union hose to gently pull off and then tilt the tank to wiggle off the "Z" bend wire arm thingy from the governor - all of the springs etc. do not need to be touched - they stay on the engine. With the tank/carb. on the bench its easier to work on it. Empty the tank of any residual fuel carefully (safety) and might as well check its insides for debris/corrosion. Undo five set screws to remove the carb. body and withdraw it upwards - watch out for a long plastic pipe/filter and a short coil spring sitting on the old diaphragm! Might as well check the filter/clean it whilst its out of the tank. The old diaphragm looked intact - but somewhat stretched and floppy. Peel it off with the old gasket and fit the new diaphragm first - to the tank face, followed by the new paper gasket, then the carb. body - get it in the right order! Re-assembly is the reverse as before - but do up the set screws evenly to avoid harming the gasket/diaphragm. After re-assembly and some fresh petrol, the engine started immediately and settled down to its old sound and performance - job done. I suppose the old diaphragm was worn/stretched a bit and was allowing too much fuel to be pumped up to the carb? Anyway - for the price of this little kit, a very simple, easy and cost effective repair. Well worth doing.

My mower engine was dying, it was terminal. A search on the Net described the problem as the diaphragm having perished/gone on the carb; it also brought me to loads of You Tube vids showing how to remove the carb from the mower motor, disassemble change the diaphragm gasket, re-assemble and refit the carb to the motor. I bought this set with a view to doing that. I was also thinking of spending £400 for a new mower, happy days eh?. The thought of replacing the gasket was a little daunting but I have to say it's nothing, nothing, like swapping gaskets on a car's carb (do we still have these in cars?) or on a car engine. It's at the very most ten minutes to do and the easiest work I've ever carried out on an engine. The vids available on the Net show you step by step, follow them and it's easy. The diaphragm & gasket supplied, there are two parts, fit perfectly. Once re-assembled my mower was working like a brand new mower, it still is. I'll be honest I didn't do it correctly first time, (I didn't follow the You Tube video instructions to the letter) so although the mower motor was working it wasn't perfect. I looked again at the instructional videos, then ten minutes later I'd sorted the problem (I hadn't taken the carb off the motor properly and the gaskets wasn't sitting properly) and it was perfect. Always follow the instructions..! A great product, perfect for my Briggs & Stratton mower motor, I'll buy it and do it all again in another few years...

Fits perfectly and cured the rough running of the engine.

Genuine Briggs and Stratton kit, you can't go wrong.

Followed a Utube video on how to replace it and it worked well after that. Apparently a little kink or curl in the gasket can form causing erratic running and some black smoke - which my lawnmower was doing. A good fix - well worth the price.

So my lawnmower was running then coughing and spluttering. The thing nearly got thrown across the Allotment!! Lol... It did sound like a fuel mix issue, either too much or not enough, eventually it started for couple mins smoked the place out then conked out. So thought I'd give the diagram change a go. Well...... I can tell you, this little piece of basically cardboard saved the day! It probably took 20mins max to change and the engine runs like a dream. You only need a few tools and some patience. Take a few pictures of it before you take anything off just incase. The patience is slowly talking off the spring to the govener arm etc. But watching a step by step vid off the tube you will see how easy it is. The local lawnmower shop charges around £50 to do this, so I'd recommend saving a few quid plus the enjoyment of fixing it yourself. This was really easy and I highly recommend it, it completely changed the running of the engine. Good luck.

Arrived quickly and looks like a genuine part. Fitted my Mountfield petrol mower fine. Bought after researching my mower problem online. It fixed my trusty 12 year old petrol mower which was running very roughly and is now running as sweetly as when I bought it, Plenty of videos online showing you how to fit this part which isn't very difficult and only took around an hour to do. A couple of tips from my experience : make sure you connect the linkages back to the carburettor properly when reassembling. I didn't and the lawnmower went into overdrive when I started it up. I had to dismantle the mower again to reseat the linkage. Buy an air filter and spark plug with this item. They are only a few quid more and I wish I had done mine at the same time, particularly the air filter which you need to remove anyway when fitting this part. Mine was all clogged up so I wish I had replaced at the same time.

Never convinced that these were original Briggs and Stratton parts. Not sold in Briggs and Stratton packaging. This fix from another supplier worked perfectly. But the mower, I put these on, starts, but still runs like a dog. Bitten the bullet and bought new carburettor instead.