excavator
Senior Member
I've been working on a JLG 40H with a Ford LRG425 engine. It acts like the timing is retarded, runs rough with no power. Then it will occasionally back fire after which it will run smooth with lots of power. Then after shutting it down and restarting its back to usual. Any ideas on this one? I quit working on gas engines back in the 80's long before DIS came out so this one is a bit perplexing.