Re starting problem

Hello every one ,i m new on this fourm kindly help me,i have komatsu pw180 wheel excavator ,after one hour work if i off the machine than engine never again till i wait one hour ,after one hour start again,
Second. if travling on rood i feel missing speed ,for 1 mint speet good but after 1 mint slow again one mint speed good ,and bad .

Re starting problem