If one burns more, I would check the fuel and air system. Make sure the fuel filters are kept up with, air filters aren't plugged and all that. You may have dirty or leaky injectors on the one that uses more fuel. You could have the pump and injectors tested at a reputable injection shop. What do you use them for that they run all the time?
They are well maintained so all the filters are in great shape. The one that uses more fuel is one of two rebuilt engines I bought and shipped down with my 4 005s. One I bought for 500 bucks had a stuck end had water in one hole. I’m sleeving it and bought a used standard piston and rod and rings gaskets etc
Each Rebuilt engine had a dyno sheet and they made 63hp but are supposed to make 53. So I think it’s getting to much fuel. I will buy an Injector tester and do them my self I have a full time mechanic that oversees the genserators daily. I just want to adjust the injectors to flow less. I will make the adjustments in small increments and monitor the fuel burn.
of the 4 one is dedicated to running my 600gph rowpu which I hope to get up and running in a month or so. The other three are for my hotel, I have a large hotel on an island near cartagena colombia
I bought them all cheap 500, 1300, 1400 & 2000 for one just rebuilt by the military that came with the rowpu. With the two spare engines I shouldn’t need a generator for 15-20 years I have 3. 002s with over 25k hours on them. One I just threw rings in and honed the cylinders. It didn’t need bearing or oversized pistons even at 23k hours lol.
Just want to fine tune them to be as fuel efficient as possible. We do everything here on the island except rewind electric motors and stators etc. But after a few more imfrastructure projects are done I want to start rewinding our own electric motors here too