Righto, your engine was made on 1st March 1983. So that will also make the machine a Mark I [inch pattern] Home Gardener [important if non-engine parts are required].

The engine Illustrated Parts List is here: http://bsintek.basco.com/MDEXResultsPages/PDFDisplayPage.aspx?fileName=Z6nkAJVJ1DajI

And the Operators Manual: http://bsintek.basco.com/MDEXResultsPages/PDFDisplayPage.aspx?fileName=flivAJX-nfBhU7y

It isn't very likely that worn rings are the cause of the starting problems on this machine. It is not advisable to use heavier oil in any case; Monograde SAE30 is the best for these engines. They invariably use oil, if run on multigrade.

Nor are ignition issues common, as this engine has the Magnetron electronic system, not the old contact points.
Unless a 'previous tenant' has altered the flywheel/coil stator clearance. A standard business card should just fit in the gap, if it's set correctly.

If it has been idle for some time, it's a very good idea to get all of the old fuel out of it that you can, and fill up with fresh stuff.

Cheers,
Gadge

"ODK Mods can explain it to you, but they can't understand it for you..."

"Crazy can be medicated, ignorance can be educated - but there is no cure for stupid..."