Paint inside the cylinder

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CTripps

Active Member
Aug 22, 2011
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Vancouver, B.C.
Hey folks

I ordered a few replacement parts, they arrived this morning.. I'm looking at 'em as I unpack the box, and it looks like theres paint overspray around the inside wall of the new cylinder. In both black and red.

I've tried a rag with turpentine, and a rag with Varsol, but neither appears to have had an effect. There's some slightly rough textured spots, my concern is that the rings will get damaged rather than clearing the paint off.

I'm wondering if a non-scratch pot scrubber might help, or some of the felt buffing bits for the Dremel, but I thought I'd check for thoughts before I risk damage to a new part.

Here's a few pics.. tell me what you think, should I clean it up (open to ideas on technique there, too) or contact the supplier for a replacement?
 

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Techbiker

New Member
Oct 27, 2009
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DFW, Texas
Try a different paint thinner.

Otherwise, have you thought about blow torching it? Paint generally starts to melt at 300 degrees F. Then you could use a metal scrubber and wipe it off.
 

Greg58

Well-Known Member
May 1, 2011
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Newnan,Georgia
CT I have used steel wool on mine, the nisyle or what ever its called is hard to scratch. I've even used fine sandpaper without a problem. I reringed one a couple of months ago and tried to sand the cylinder a little so the rings would seat, sandpaper didn't seem to hurt it.
 

Davezilla

New Member
Mar 15, 2014
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San Antonio Texas
Try lacquer thinner or acetone to soften up the paint and see if that'll get it off... Lacquer thinner should eat into it enough to just wipe off with a rag and acetone has about the same effect but it's a little more agressive and evaporates really fast so ya gotta work fast.
 

2door

Moderator
Staff member
Sep 15, 2008
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Littleton, Colorado
Is it paint, or powder coat? I've never had a black engine, except for those I've painted myself. I don't know what they use from the factory

Tom
 
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Theon

New Member
Jan 20, 2014
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FNQ Australia
I'd say a good chance it is powdercoat, I'd soak a rag in thinners, and let it sit on the paint you want to soften, then carefully use a sharp flat blade to scrape the 'paint' off.
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
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I'd be screaming for free replacement. Simply unacceptable, ESPECIALLY if it's powdercoat.(Very unlikely from factory)
If you have to deal, get some MEK or truly aggressive solvent before you go sanding it.
That cylinder bore plating is FAR too thin as is. Sanding does not help.
 

GearNut

Active Member
Aug 19, 2009
5,104
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San Diego, Kaliforgnia
If the above mentioned, highly recommended solvents don't do the trick, the one chemical that I know of that will soften, lift and positively ruin any paint is good ol' DOT-3 brake fluid. Just give it a little time to work it's magic.
It will not affect powder coat though.

Also, I am surprised that commercial paint stripper has not been suggested.
 
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2door

Moderator
Staff member
Sep 15, 2008
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Littleton, Colorado
If it happens to be powder coat they do make stripper that will take it off. I had a differential housing powder coated and they got it in the bearing cups. I raised heck and they gave me a jar of stuff and told me to be careful with it. "Don't get it on your skin or in your eyes". Whatever it was it ate through the powdercoat like it was paint. Cleaned it down to bare steel again.

Tom
 

Kioshk

Active Member
Oct 21, 2012
1,152
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Connecticut
I suggest just using a razor-blade to shovel it off...kinda like shaving your face: you can get it off without damaging the chrome.
 

CTripps

Active Member
Aug 22, 2011
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Vancouver, B.C.
Thanks, folks... there's a few things here I can follow up on.. I will call the supplier and raise a stink in a while (once they're open). I have some acetone, I'll try that next. Possibly in combination with a new non-scratch scrub pad and/or some "0000" steel wool. From there I can go to sandpaper (probably 400 grit) as well.

I'll report back the results of my attempts.
 

CTripps

Active Member
Aug 22, 2011
1,310
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Vancouver, B.C.
Update, it looks like acetone will work, when mixed with the appropriate amount of elbow grease. The "Scotch Brite" blue scrub pad may also help, the synthetic it is made from does not appear to be affected by the acetone, so added bonus there.
 

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,505
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Ridin' inSane Diego, CA.
Just paint it silver and install it. Use some assembly lube and you'll never know the difference.

I'm sure the piston rings with the engine heat and turning 5,000 rpm will make it all disappear in minutes.

Or wipe it with carb cleaner and steel wool for extra ring seating......don't forget some assembly lube to the rings and cylinder while installing.

Call a mechanic if in doubt: 1 (800) 968 TOOL (8665) ;)
 

rackemblue

New Member
Jan 20, 2014
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Orange,Tex
Brake fluid will deslove dried paint in only a few hours. You want to be sure and get all the brake fluid out by useing gas or thinner and then wipeing motor oil on the area where the brake fluid was to prevent rusting it will rusting it will rust overnight if not lubricated right away.
 

GearNut

Active Member
Aug 19, 2009
5,104
11
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San Diego, Kaliforgnia
The bore is Nikasil plated. Nikasil doesn't rust.
You are absolutely correct though in regards to cylinders that are solid cast iron or aluminum with a cast iron sleeve.
 

rackemblue

New Member
Jan 20, 2014
72
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Orange,Tex
.duh.You'r right Nikasil is a nickle and silacon mixture like chrome lining and that's why you do not want to scratch it. I was not aware that you were talking about a nikasil lineing in the cylinder, But brake fluid will take the paint off without damage to the lineing. Just trying to be helpful. I have used brake fluid as a paint stripper for many metal surfaces and it works great without damage to the metal surfaces.