I tried a product called 'kroil' sprayed into the cylinders and soaked overnight. The piston tops are still black, but the thick layer of carbon is gone. I changed the oil and added some mmo and going to run a few tanks of fuel through it with mmo in the tank. If you are interested in 'kroil' go to 'kano laboratories' on the net. I've used their products for removing seized bolts, and this product seems to work equally as well.

 

Why did you do this?
What was the reason?

Have you noticed anything since doing this?

 

What about all that sharp crud (when it dries) that you washed down around the space just above the top compression ring? That ought to add about 30K of wear on the first 100 miles.

 

Carbon build up...free high compression engine

lp

 

Aero Kroil is the best penetrating oil you can buy, but it is pricey. Orange can, "The oil that creeps", is the deal. If you spray a fastener that will not back off and let it sit overnight, you will not believe how it creeps into the tightest places. I have used it on classic cars and trucks for years. Available in gallon, and even big drums, too.
Your carbon in the motor didn't stand a chance!
I advise you keep the kroil on the top shelf in the back for the important jobs, keep the WD40 and the other lightweights up front.
Excellent starting fluid for diesel engines, BTW...

 

Oh hell yes, 10 to 1!
I don't see a problem here unless it is all that carbon which has been broken loose and is now running up and down the cylinder walls and getting squeezed between the valves and the seats.
Call me crazy.

 

OP saw some carbon in his motor the other day that concerned him, this is the update...

 

And tiny 'chunks' stuck to the exhaust valves on the way out...causing burnt valves.... I'll leave my carbon on the piston where it belongs.

 

OK, here is the story (or back story)

About 8k ago, I was having oil puking out of the air filter. It had been getting progressively worse. Knowing the end all solution was to vent it to the ground, that's what I did. This problem had been around since about 10k. OK, puking problem solved. But, the oil had been ingested by the engine for about 32k. Fast forward to a few months ago..... I had some occasional ping around 2500-3000 rpm. Tune up time. Cleaned the air filter, new plugs, new fluids, and ran seafoam through the throttle body. Ping was completely gone. Being an auto tech, lots of time on my hands, I borrowed a snap on borescope (nice unit btw) and took a peek at my top end. Wow! It looked like burned corn flakes on top of my pistons. So I researched what would soften the carbon, not just break it free and cause even more problems. The kroil seemed to be the best solution. After letting it soak for 24 hours, I ran the engine and misted water into the throttle body as a final 'steam clean' When I looked into the combustion chambers this time, I still have black on the piston tops but no 'corn flakes'. I checked the oil to see if I had any discoloration, and the oil smells profusely like 'kroil' so out it came. What does it all mean? The kroil softened the carbon, the kroil cleaned the Rings on its way past the piston into the crankcase, and now my engine is significantly cleaner than it was. I'm going to give it a test ride and honestly I don't expect any amazing results, just a cleaner engine, that will stay cleaner now that I have the oil breathers vented to the ground.

Thanks for listening. Ride safe!

 

Oh, and at 40k I can still clearly see the cross hatch in the cylinder walls with the borescope.