Briggs and Stratton Sprint 375 - Cuts out after one minute

[grubberOM15]

Ok so the engine is about 20 years old but it has never ever let me down before. From cold engine starts and runs as normal. But after about a minute the revs start to slow down and then it shuts down. Remove spark plug whilst still hot, it sparks fine but appears dry. Any ideas please.

 

[bertsmobile1]

debris in fuel tank clogging pump
Pump diaphragm worn out

 

[grubberOM15]

Thanks. There was indeed debris in the tank. I can't see a pump as such, but I changed the carb which came with a new diaphragm.

 

[bertsmobile1]

The diaphragm you changed is the pump
The long tube has a gauze on the end that gets clogged
The diaphragm has to go against the tank then the gasket & finally the carm on top.
Very common for people to get them in the wrong order

 

[grubberOM15]

Thanks. When I took the carb off, which has been undisturbed for over 20 years (and since new) the gasket was definitely next to the tank. If you're sur I'll give it a go. But I must admit it would make sense.

 

[bertsmobile1]

the tank has 2 little holes in it which combined with the flaps on the diaphragm makes the pump