I have had this mower since 1990 and basically just used it without maintenance other than top up of engine oil. I went to use yesterday and have a loss of power when trying to mow. Checked spark plug and it was black and sooty. Filter was quite clogged. I can not read the spark plug number to replace - I can not find the manual? I also do not know the number for replacing the air filter? I cant seem to find info. on the web that helps?

Ian, May 2012

Try a compression test. If low you may need to regrind the valves. Place a paper towel at the end of the exaust pipe and rev the engine. If it is black with sooty deposit this would indicate a worn engine. The bad news it would mean an engine overhaul involving a possible rebore with new pistons/ valves etc;

Keith, February 2020

I can help with an air filter - please describe it. Plug is (or should be) a Champion RJ17 or RJ19 or equivalent - not hard to get but I can help with that, too.

Your symptoms point to nothing more than a dirty filter. Don't be tempted to use it without the filter element. Life expectancy of the engine is about 30 minutes if you do - which would be a pity, as the engine will last indefinitely if looked after.

phil_saunders(a)bigfoot.com

Phil Saunders, June 2012