Cleaning 20 year old dirt in engine bay

I use Simple Green. Seems to work well. Spray it on, let it soak for a bit, brush, repeat if necessary. Use a combo of SimpleGreen, dishwashing soap and water in my ultrasonic cleaner.

 

the HF cleaners don't last long

 

The one I have looks like this. I opted for the manual control version thinking electronic controls aren't as reliable. Cheap. Works well and I'm happy with it.
https://www.ebay.com/itm/Stainless-...710505?hash=item3dae5376a9:g:TnsAAOSw-u9fkQ4m

 

Some pics from my ZX9r restore/build. Used mostly paraffin/diesel, wd40, brake cleaner, soap n water in conjunction with good old elbow grease , scrubbing brush and electric toothbrush thing for car wheels.

 

I came to say that I also use Simple Green, with a wire brush. Let it soak for 5 min, go at it with a wire brush, break it up, wipe up, go for a 2nd round, then think about briskly using some carb cleaner here and there. Thats what I used for the area around the chain/swingarm filth that was just as old looking as yours. I have a feeling there are suggestions here that may work better but I will say that I was very surprised how good it worked, but you need the wire brush.

 

since it looks like water got into the one cylinder where the intake looks rusty, you may have bad piston rings and a corroded cylinder, so the bike may never run right. was it stored with carbs removed ? suggest a compression test b4 you do much more work.

 

Some PB Blaster in the exhaust port, down the intake, and through an open spark plug hole on that cylinder is probably a good idea too.

Jose

 

I eventually used acid for aluminum... drill and few different brushes...