Flymo mv100 not working?

-Today however I changed a split fuel pipe after this it worked fine however after 5 mins is started being noisy so I shut it down. It stopped dead and appeared to be seized couldnt pull or turn the blade. Italso appeared hotter than usual. After 2 mins and a wee fiddle everything started to work. But then this repeated few times. Any ideas or advice could it be not enough oil in the fuel mixture ???