ORIGINAL: albsurfer
CYMAZ has the right idea. In a recent mag article ''DAWN POWER DISSOLVER'' was mentioned to use. It got my 55AX VERY clean without a lot of muss & mess. Use it in an open area, preferably OUTSIDE because it smells like a low power OVEN CLEANER. I gave it one coat, let it sit for 20 minutes, brushed it with a toothbrush, rinsed with water. I did another coat like that and a lot came off. On the 3rd treatment, I used med-hot water to rinse it and gave it one last scrub with a toothbrush and WOW, almost everything came off of the engine, including in the fins! I think the warmer water activated the cleaning ability of the cleaner more. GREAT STUFF.
Anyone who has had a coolant leak or a heater go bad in their car knows how bad, and caustic, using anti-freeze can be.
In Harry Higley's book ''All About Engines'', he cleans out the carb with a toothbrush, packs paper towel into the carb intake and the exhaust. He then recommends BRUSHING on carb cleaner, give it a short time to act, then use an acid brush to clean off the goop. Rinse the engine with water inbetween applications and give it a final rinse when you are done.
The problem is, Harry's book was written some time ago, long before the introduction of the Dawn/Fairy pot and pan cleaners. I'm not saying that his advice will cause harm. Not at all. I'm saying that there are better methods available today.
I use Dawn Power Dissolver (?) (dang memory) for light jobs. But if you have a really crusty coated engine, I can't see spending an hour or two of knuckle busting scraping and brushing when an over night soak in a warm crockpot of Prestone 100% antifreeze will do an even better job.
Ed Cregger