We have an SP470 fitted with a Briggs & Stratton Model 10D902 motor. The mower is running very hot rough and slow, cuts out frequently, and is guzzling petrol at a rate of knots.
I've done the superficial checks (plug, air filter etc.) but with no success.
I hope someone will be able to provide some help.
Simon

Simon Hammerton, June 2008

my lawn mower took a long time to start.The cord did not pull back easily.Eventually it did start...But then would not stop until petrol ran out.

What could be the fault?

John, July 2011

HI guys
I have just replaced the diaphram on my fathers sp470, very easy £1.05 for part and saved £70.00 on full service, just remove the cowelling cover undo the two bolts fixing the petrol tank then remove the choke wire from the engine side, all you need to do then is unscrew the five screws holding the carb to the petrol tank, it will then lift off, give a good clean and fit the new diaphram, reverse the process to refit and it runs a dream.

lawnmowernovice, May 2009

I seem to be having the same problem, are there any easy to follow instructions how to change the diaphragm? Sure its not as simple as unscrewing the carb replace the part and screw back down. Does the throttle need to be kept in any particular position ect..Many thanks for any help.

Steve, December 2008

I have the same problem did you manage to fix it?

Thanks
Jamie

Jamie, July 2008

Replace carb diaphragm - almost guranteed fix.

phil_saunders@bigfoot.com

Phil Saunders, June 2008