Cleaning heads and pistons

[Ducologist]

Can anyone lend advice on carbon removal? I once received advice from a grizzly old mechanic to use easy-off oven cleaner, which actually destroyed a set of Harley pistons. Brake cleaner did a great job on the head and valve seats but not the valves. I haven't even tried to remove the buildup on the piston crowns, but it's pretty thick. I saw that some people use wire brushes but I'm worried about scratching the valves. Any advice is appreciated!

[t_bare]

Maybe try Seafoam?

t_bare

[waco748]

If the engine is disassembled, guys in other forums are talking about using Permatex Gasket Remover or soda blasting. Some also talk about using non-metallic kitchen pan "Brillo" pads. If assembled, Seafoam is pretty popular and I've used it on other bikes and 1/2 ton pickup trucks.

I think the secret is to use a good quality fuel; I don't buy from Walmart or HEB as the additives are different concentrations than those found in Texaco, Chevron, or Exxon fuels.

People in other forums also talk to using the correct fuel grade. 93 octane has excess BTU content at some RPM levels and the wasted BTU content turns into carbon; some talk to using whatever octane doesn't cause knocking but I'm not too keen on that as I don't want knock when I want rev power.

I keep the rpms at 4k on the street to avoid wasting BTU content (but then, I also use more fuel) and, IMHO, prevent carbon buildup.

[Rev. Dr. Moses P. Lester]

i've had good luck with soft wire brushes, like brass. i've heard that a stiff sharp-edged piece of plastic, like an old credit card, can be good. i had to do it real slowly and carefully with a screwdriver once, because the 50 year old piston had carbon built up on it that was the consistency of baked-on clay. i've never found a solvent that did much good.

[Gearbox]

If you have access to a friend with a bead blaster machine , you can use Walnut shells.
These are used where damage is to be avoided and used in the aviation industry.

[tonered]

I used brake cleaner and a phenolic scraper. It took a while. The cleaner loosened the crud that tbe scraper removed. Then, it was a matter is wiping off the final residue.

I'd love to peak in there and see how it is holding up.

Have a good one.

[Spensersdad]

In my experience removing carbon is the one thing WD40 is good for. You have to let it soak though.

[Ducologist]

So the winner so far is a dremel with a wire brush. The exhaust valve is surprisingly stubborn...

I let it soak in WD40 overnight and it didn't do much. The credit card was not hard enough.

[Spensersdad]

Be very careful with the wire brush on aluminum!

You might try scotch bright pads specifically for aluminum. A good auto parts store will have them.

Back in a former life as a foreign car mechanic, I used these with a die grinder to clean aluminum parts, combustion chambers, gasket surfaces, etc.

[ducatimike]

An old mechanic years ago taught me using the round end of a hack saw blade to remove the carbon build up inside the head.

Mike