Briggs & StrattonCarburettor Diaphragm/Gasket Kit. 795083

When fitted the motor worked much better.

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...

You realise when you see a new dual-layer gasket just how stretched and worn out the old one has become. One layer has a 'dimple'—it bears on a light spring and is, in effect, the fuel pump, so must be in good, unperforated condition. Take the odd photo as you go, to aid reassembly later. YouTube has a video that can help, too.Remove the spark plug cap. Remove the air filter (one central screw) and the fuel tank (two bolts). This is an American engine, and I found the larger bolt needed an A/F ring spanner manoeuvred behind the fuel filler cap. The air filter contains an oil-soaked sponge element. Retain the rubber pull-off fuel pipe elbow, and the flat-type O-ring that sits at the top of the carb's vertical venturi as a seal. Undo five Phillips screws to release the carb upper from the carb body (that forms part of the tank) and carefully wriggle the little steel actuating rod out of a little hole in the throttle's butterfly spindle. Note which of the two holes! And do NOT stretch the lightweight springs that control the air vane—they auto-regulate the engine's revs in use. Usually the springs are OK but replace any damaged spring. The old gaskets should come away fairly easily. Note which gasket is upper and which is lower. The new gasket set slips first over the vertical plastic fuel uptake pipe that descends almost to the base of the tank. Clean everything with petrol or, better for your health, white spirit. Don't damage the delicate fuel filters. Reassemble carefully, especially when wriggling the little rod back into its little hole. Replace the spark plug cap, prime well and ... good luck!

Easy to replace. Lawnmower running like its new again.

When the mower conked out after 12 years a bit of searching on you tube showed it might be fixable at home. So a new spark plug, a can of carburettor cleaner and this gasket and diaphragm set was all I needed to avoid an expensive repair bill or buying a new mower. The gasket set is accurately cut and seated easily, and the previously conked out mower roared back into life first pull. So very happy with this, confident about trying more repairs, and saved some money in the process