I have Briggs and Stratton pressure washer that won't start when attached to pump. It starts easily when pump is disconnected. Any opinions?

Do they have spark wires? I’m getting a tune up and want to buy my own parts. My grandfather told me to buy spark plugs and wires but I can’t find the wires online....

I need a diagram identifying all the in/out lines of the engine, esp. the front lower half near the lower belt wheels. or if you know which line is in the picture (the leaking one)...