I have a mountfield lawnmower with a briggs and stratton engine. When I prime it 2 or 3 times it starts and runs perfectly for about 30 seconds then cuts out. I've cleaned the filter and spark plug, it seems like it maybe a blockage somewhere, any ideas anyone.

Hi,
I gather that this is a walk behind mower since you prime. It could be a blockage in the tank or fuel line. More likely it is the inlet needle and seat if it is a float carb. That would part# 398188. If the tank mounts to the top of the tank, it is the diaphragm or pickup tube.
Peace,
Clarke

Thanks again Crig, I've got it going but it's a bit gaspy and slow any ideas how to speed it up a bit ?

Hi,
I really would need the engine numbers above the spark plug or muffler to know which exact engine you have.
Peace,
Clarke

Hi Clarke,
Thanks for the trouble your taking to help buddy, this is all the info from above the spark plug.

Model:- 10D902
Type:- 0141 B1
Code:- 02032754

Being a Brit I'm guessing a muffler is what I would call an exhaust ?

Cheers buddy !

Hi,
I knew it was a UK problem since I know what a Mountfield is, and others , from previous experience!
I will attach the parts breakdown (IPL) for your perusual.
First is to remove the air cleaner and screw. The remove bolts 190 and 190A. Ease the tank and carb off the intake pipe, tilt down carefully the unhook 201 from carb without damage. Remove the 5 screws from the carb that attach itit the tank and clean 393. Consider replacing 394 before reassmebly.
Peace,
Clarke
PS Need more direction, please do not hesitate!

Hello again,

Clarke you are a star, I shall take great pleasure perusing that most comprehensive manual you have sent me. Thanks again bud, much appreciated sir.

Hi Clarke,

You are the man, sisters mower running like an Indy car. Didn't replace the gasket because she was desperate for the mower, but I'm going to completely overhaul it during winter so will do then, once again thanks for all your help.

Cheers Pal