Check your blade plate to see if it is loose and also check your spark plug for a whisker on the electrode.
As to a manual on line I do not know of anyone that has one. I only supply information on problems with machines as you will see if you have a look at the posts that I have done this month.
Regards,
Bruce
Regards,
Bruce
Please do not PM me asking for support. Post on the forums as it helps all members not just the individual.