There are after market Honda engines that may fit.
At some point I’d like to see about a replacement motor for a long sitting Mighty Mac pressure washer rig.
https://www.docut.com/ps350t-10-mighty-mac-sprayer
The link above has a much newer model but it’s an idea.
The one I know about has been sitting for 15 years. I got it to kick over once a couple of years ago just playing around.
It has a Briggs Stratton motor mounted on it and of course, the location of the make/model is impossible to see where the ID plate is to find a possible replacement carb.
I keep thinking I will take it to the local Briggs Stratton people for a new motor due to age and sitting up. The biggest thing would be connecting to the pump.
When I had it sort of running, the pump did show pressure building. It might be intact.
Last weekend I gave it a shot of ethanol free down the carb like the last time. The engine spun over but that was all. I didn’t have any sockets with me to check if the plug was fouled.