boulter camray 5

Hi . I just serviced a Boulters Camray 5 150/200. I always first run it for a minute to check if it starts ok etc before I start and sounded ok. Quite a bit of carbon on the baffles, just presumed not seen a service in years. Nozzle and blast tube looked ok. Written in marker on the side...

My Boulter Camray 5 was recently serviced by an engineer but has not been right since! This was about 10 days ago. From an initial start up it runs for about 20 minutes then stops. After 5 minutes or so it restarts, runs for about 5 minutes, stops for 5 minutes, runs for 5 minutes etc. etc...