Hi Peter
It sounds to me that the clutch is slipping when you try to start the engine with the crank handle. I would suggest you check that there is a little free movement on the clutch lever as you start to pull it up, if not, there is possibley pressure on the clutch thrust causeing the clutch to slip. Adjust the clutch lever to allow a little
free movement and see if that does the trick. If the clutch is slipping and you start the engine with the pull cord and use the rotavator you run the risk of burning the clutch out completely. Having said all that it may be the clutch is worn out!!
All the best. Eric
