Hi Grumpy,
Thanks for your quick reply. I wish I had found this forum earlier too....
I will check the tappet clearances and let you know how I go - obviously a common fault. I am pretty annoyed because we have always had it serviced (by one of two different shops) and no-one has picked up on this problem. Just wanting to sell me a new mower I guess.
As for the air filter housing, is this something that can be repaired or is a new housing required?
Regards,
Andy