Lull 844 - engine cycling

Please see the attached video (the website made me zip it)
or here;
The engine is making a cycling sound. I've had the machine for 3 years, and it always did this, but the cycle intervals was about 20-30 seconds. Now, it is every 1-2 seconds. It doesn't sound normal.

I have no idea where to even start...

thanks

First thing is to check the accumulator precharge pressure. If it's not holding pressure it will do that. Take the accumulator off and turn it upside down and press the valve in with some sort of tool from the side-don't have your hand close to the valve. If oil comes out have the accumulator resealed. Next thing could be that you have a bad internal leak causing the accumulator pressure to fall rapidly and the machine is cycling to recharge it. What's your model and serial number?

Thanks, this is very helpful. I read about the accumulator in the manual and it sounds like it could be the culprit.
I attached a pic of the model and serial.

The accumulator is always the first thing to check. You can't really check anything else until you know about the accumulator pressure. Good luck with it.