My 10-year old Mountfield Omega 42 lawnmower's fuel mixture seems too rich: engine smoking, spark plug carbonised, smelss of unburnt fuel, engine floods easily under load. Engine starting and idling fine, air filter clean. The only time it runs well is the 20 seconds before it runs out of fuel ... Any ideas how to adjust it? Note push-prime, no choke, automatic throttle (via airflow from flywheel) and doesn't seem to have adjustment screws on carburetor.

KT28, May 2007

I changed the gaskit / diaphram on mine , much better now.
This fits between the carb and the tank and seems to be part of the mixture control system.
£2.35 from Ebay ,
http://stores.ebay.co.uk/Terrys-Chainsaw-Chain
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=260231055453&ssPageName=STRK:MERFB:IID

Ian Paul, May 2008

I changed the gaskit / diaphram on mine , much better now.
This fits between the carb and the tank and seems to be part of the mixture control system.
£2.35 from Ebay ,
http://stores.ebay.co.uk/Terrys-Chainsaw-Chain
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=260231055453&ssPageName=STRK:MERFB:IID

Ian Paul, May 2008

I changed the gaskit / diaphram on mine , much better now.
This fits between the carb and the tank and seems to be part of the mixture control system.
£2.35 from Ebay ,
http://stores.ebay.co.uk/Terrys-Chainsaw-Chain
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=260231055453&ssPageName=STRK:MERFB:IID

Ian Paul, May 2008

I changed the gaskit / diaphram on mine , much better now.
This fits between the carb and the tank and seems to be part of the mixture control system.
£2.35 from Ebay ,
http://stores.ebay.co.uk/Terrys-Chainsaw-Chain
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=260231055453&ssPageName=STRK:MERFB:IID

Ian Paul, May 2008

I had the same problem with my Mountfield lawn mower with a B&S engine. I dismantled the carb and cleaned it in petrol. It now works fine.

AG, July 2007