Chosen Solution
The motor on my Karcher pressure washer has stopped running smoothly. It occasionally stops altogether as if overheating but does not appear hot. During operation it is constantly surging in power and then slacking off. Sorry for the un-technical description.
Is the water supply sufficient. Check that any filter is clear. We used to suffer from low mains pressure and the Karcher would stop as it allowed enough water to get to it’s innards.