How do I clean the piston crowns?

[FormerGlory]

Hello there, newbie here. Currently restoring my '80 XS1100S. Engine is out and all parts are at the painters and powder-coater.

The head has been completed (sonic cleaned, milled, valves and seats ground, and new valve seals). The lower end is in great shape so I don't want to pull the pistons...however the crowns have a thick layer of carbon buildup. The soot ring is very brittle and most of it came loose when removing the head gasket.

What is the best way to clean each crown and get them clean and shiny again without removing the pistons? The manual just says to "clean them" without any other details.

Thanks

[jetmechmarty]

I'm sorry I don't have direct experience with this engine, but aren't you concerned that the new head will cause leaking at the rings?

[crazy steve]

If you have the head off, it's not that much more work to pull the cylinders to get easy access to the pistons. But if you're determined not to do that, the best method is to bring each piston up to TDC and clean the carbon off. For the actual cleaning, I'd hit it with a flat scraper to get the chunks, then follow up with a maroon scotchbrite pad. You'll never get them spotless, but this will clean off 98% of it. You will need to move the piston up and down a few times to clean out the 'gunk' that will collect between the top ring and the top of the piston (and you'll never get quite all of it), then flush it with some light oil.

DO NOT use any sort of silica-based abrasive (sandpaper), as this can leave particles in the bore.

[XS1100_OEM4ME]

Steam Jenny

Hello there, newbie here. Currently restoring my '80 XS1100S. Engine is out and all parts are at the painters and powder-coater.

The head has been completed (sonic cleaned, milled, valves and seats ground, and new valve seals). The lower end is in great shape so I don't want to pull the pistons...however the crowns have a thick layer of carbon buildup. The soot ring is very brittle and most of it came loose when removing the head gasket.

What is the best way to clean each crown and get them clean and shiny again without removing the pistons? The manual just says to "clean them" without any other details.

Thanks

Does the guy at the paint shop (or anyone you know) heav a small Steam Jenny? If so, take each piston to TDC, steam "across" the top of each one (across is to not force excess steam into the motor) a good Jenny will make them look and work like new. If you do sand, scrap or do any thing abrasive you will rough up the surface and cause more carbon build-up and posable detonation down the road. Open the oil fill cap and do it in the sun (even if it is cold out) and the steam will evaporate and not hurt anything, wont hurt the powded coat if it is already done, just make sure you only hit the pistons tops, a couple secounds each and "like new"

[FormerGlory]

Thanks to all, appreciate the insight. I'll look for a Steam Jenny.

[XS1100_OEM4ME]

Steam cleaning

I did a surch for Evans Co. and came up with this:

http://www.cylex-usa.com/company/joh...h-8347366.html

Don't know how close or $$$$ but might help. If you have other parts that need cleaned, ie frame etc, this will take off any grease, dirt and 30+ years of anything

Thanks to all, appreciate the insight. I'll look for a Steam Jenny.

[Rickrod3]

Supose you did remove the pistons would it be okay to use a buffing wheel?
I would do a soap and water wash after.

TIA
Rick

[petejw]

hi formerglory,

as a cpl of others have said, id remove the barrels
and clean the pistons properly, if u have a thick layer
at the top of the piston, ull more than likely find carbon
in the ringlands, side of the pistons, the pistons also have oil holes under the
oil rings and they tend to block up as well.
heres a link to mine

http://www.xs11.com/forum/showthread.php?t=31824

[XS1100_OEM4ME]

Paint prep.

I would use a good paint prep. to clean after buffing, leaves them clean and ready to instell

Supose you did remove the pistons would it be okay to use a buffing wheel?
I would do a soap and water wash after.

TIA
Rick

[Rickrod3]

I would use a good paint prep. to clean after buffing, leaves them clean and ready to instell

Thanks for the tip

[LuckyEddie]

cleaning piston crowns

While I had the head off my 80 MNS, I used a soda blaster to get the carbon off the pistons. Worked great, nice and shinny. Do it outside though, gets everything dusty.

[XS1100_OEM4ME]

Polish

With the head off, it is so easy to remove the jug's A great chance to check all the cyls and rings and clean / fix anything and everything I would (and I know I will get heck for this) check / hone the cyls, pop the pistons off (easy to do with a home made pin press, check Clymer manual, couple of bolts and nuts) Sounds like you have a bench wheel, so polishing the tops of the pistons is a great idea IMO, then spray clean with Klean Strip auto prep, cheap spray can at any auto supply store, leaves clean, ready to install

Supose you did remove the pistons would it be okay to use a buffing wheel?
I would do a soap and water wash after.

TIA
Rick

[petejw]

With the head off, it is so easy to remove the jug's A great chance to check all the cyls and rings and clean / fix anything and everything I would (and I know I will get heck for this) check / hone the cyls, pop the pistons off (easy to do with a home made pin press, check Clymer manual, couple of bolts and nuts) Sounds like you have a bench wheel, so polishing the tops of the pistons is a great idea IMO, then spray clean with Klean Strip auto prep, cheap spray can at any auto supply store, leaves clean, ready to install

removing the pistons from the con rod isnt that hard and
only needs a slight tap with a hammer and extension to remove.

if ur polishing the pistons using a buffer and rogue i wouldnt be
using any cleaner, the pistons are already clean and the buffer/rogue
puts a film over the alloy to protect it, removing the film will cause
the alloy to anodise.

[XS1100_OEM4ME]

Pete

you know I love you Pete, but, the reason I said to spray clean with prep clean "instead" of washinig with soap and water is, prep clean leaves no oxidation and removes any abrasive compound that might remain

removing the pistons from the con rod isnt that hard and
only needs a slight tap with a hammer and extension to remove.

if ur polishing the pistons using a buffer and rogue i wouldnt be
using any cleaner, the pistons are already clean and the buffer/rogue
puts a film over the alloy to protect it, removing the film will cause
the alloy to anodise.

[petejw]

you know I love you Pete, but, the reason I said to spray clean with prep clean "instead" of washinig with soap and water is, prep clean leaves no oxidation and removes any abrasive compound that might remain

lol,
i wouldnt wash em in soap and water either,
if u use the buffer properly without overloading it
with compound there shouldnt be anything left
after buffing and if there is a soft polishing cloth would
be enuff to remove any xs compound.
isnt the prep clean a wax and grease remover?
that would also remove any film left by the compound/rogue

have a look at my pistons they were just
buffed and left alone after that, ive got over 500k's on them
atm and they look as good as they did when i put them in.