al-co rotavator engine

NO & NIce

I know this is a bit late after your enquiry and you've probably found the answers you need but if not:-
Some time back I was give a non-runner Alko MH5000.No name plate on the engine but I found some numbers on the rear flange of the engine. After many hours of searching I discovered that it was a Tecumseh engine but made in Italy(Tecumseh Europa) factory since closed down. That was the reason none of the serial numbers made any sense when I tried to look them up on the Tecumseh(American)  web site.  If you can find any ID numbers try contacting Tecumseh UK 01784460684(tecumsehuk.co.uk) they were really helpful in identifying the engine.
After talking to them I ordered a manual from the Alko main dealers-Rochford Garden Machinery Ltd 01963 828000, again very helpful.
The problem I found with my non runner was a sheared key that locks flywheel and crankshaft. Although the crankshaft nut appeared tight, the key had sheared and the flywheel slipped, so while there was plenty of compression and fuel, the ignition timing(determined by the flywheel being in the right position on the crankshaft) was way out.
Hope this is some help.
Yodapete
PS.  Sometimes when trying to start this engine, it gives a vicious kick-back, enough to yank the starting cord out of your hand  and snap it back to engine cowl, if you don't have a real good grip on the cord handle.  This might have been the cause of the sheared key initially