Primer Bulb Problems - Briggs & Stratton 3.5HP Classic

Hello forum,

I'm relying on a very old lawnmower at the moment which is powered by a Briggs & Stratton Classic 3.5HP petrol (whoops - gasoline for any readers from the USA) engine.

It was working ok until a few days ago when I accidentally let the engine run with an empty tank. The engine cut out of course. When I refilled the tank later on, I couldn't get the primer bulb to work. Some resistance to my finger and a slight "sucky" noise, but no fuel coming through.

Thinking I must have dragged some muck into the carb and blocked it when the petrol ran out, I've taken everything apart this morning and given it a good clean. However the primer bulb still isn't working.

The inside of the carb is nice & clean now. The primer bulb is fairly new and in good condition.

Does anyone know what might have happened & how I might go about fixing it?

I did notice when inspecting that the gasket next to the diaphragm (between fuel tank and carb) had a small tear in it. Could this be the source of the problem? (the gasket and diaphragm kits are very cheap so I might replace them anyway just as a bit of regular maintenance)

Thank you,
Alan.

Yes, that gasket could be your problem. You could be sucking air instead of petro. I would start by replacing that gasket and make sure you have a good seal. If that doesn’t solve the problem, give us the model, serial and type numbers off the engine, so we can see which carb you are talking about.

Thank you.
Sounds like a plan. I've ordered the gasket/diaphragm kit on eBay so I'll give it a go & see what happens.
Alan

When you fit it you will find it a lot easier to do upside down or you will end up tearing the diaphragm again.

When you pulled it apart did you pull the pick up pipe off it clean it ?
If you did double check you have pushed it back home fully, they are bloody hard to get back in properly.

I keep 15 to 20 of those kits in stock at all times.......... I already used 5 this past 2 weeks............ Ethanol eats those up all the time ~!~!

Boudreaux In Eunice La. said:

I keep 15 to 20 of those kits in stock at all times.......... I already used 5 this past 2 weeks............ Ethanol eats those up all the time ~!~!

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Exactly why I do not run that crap in my small engines.