I bought this to help drive in 350 4” fence posts. I gave up and put them in with the normal heavy post knocker. It’s painfully slow, has very little impact even on soft ground and is deafening. I think it would take 5 or more minutes to drive a 4” post in even 6 inchs...I’d Already done pilot holes with a wrecking bar! It got to a point where it was hammering away but the post wasn’t moving any further and it just started bashing the top of the post up.
I wouldn’t bother, either pace yourself and use a traditional fence post knocker or get a contractor!
This is a sturdy well made piece of kit and it weighs a bit so a good job it come in a case on wheels.
It started first pull and the engine ran nice and evenly. Using a crow bar to make a pilot hole it quickly knocked in some 3" posts and was easy to keep straight. Ear defenders are a must and a pair of padded gloves to absorb the vibration are a good idea. This is so much easier and way less exhausting than a manual post rammer and it will go where a vehicle or tractor cannot.
The manual is short on detail as to oils etc but it is relatively straight forward.