Sharing my experience with the grey Nightster engine, and how I got mine looking clean.

different methods I tried (in this order)

-Mixed hot water and regular auto soap, scrub with hard bristle brush + thorough rinse ~ Did absolutely jack
-Mixed hot water and Sunlight dish soap, scrub with hard bristle brush + thorough rinse (thought this was the answer) ~ Very little > Nothing
-High pressure wash, scrub, rinse ~ Nothing
-CLR mixed 50/50 water, thorough rinse ~ Nothing
-Simple Green full strength, scrub with green scouring pad + thorough rinse.

After all this I was still unhappy with the results.
The Simple Green didnt do anything to the spots as most showed right up after it all dried. I did notice that one part that I scrubbed harder with the scouring pad felt much smoother than the rest of the engine which is extremely course. Dried looking almost like a matte/Satin finish rather than grey sandpaper, and clean!

Decided to give the whole bottom end a light scrub with the scouring pad, No chemicals, not even wet. Now its cleaner than ever (since I've owned this bike).

First picture is what it looked like when I bought the bike. Second picture is *after* all the chemical wash's, still looks like garbage. Last 2 pictures are after the scouring pad, and a dry wipe (may be in different order after uploading) **If you click on the pictures you'll see them in better detail**

 

Nice Job, Looks Great.

 

s100 goods - https://www.s100.com/

gunk engine cleaner & brightener - http://gunk.com/home/products/engine...egreasing.aspx

pig spit - https://www.pigspit.com/

 

Interesting....over the years, many co-members have not found a product to cure this grey engine paint staining/ cleaning.

I'd gather what the OP is writing is that the scouring pad lightly sanded the grey paint surface which contained the stains.
An option I suppose....I might try it.

 

Ive heard good things about S100 on many bikes. But, I'm fairly certain it would still not do anything on the Nightster engine. Maybe the black wrinkle and chrome bikes, but the grey engine is literally like sandpaper. You cannot even run a cloth across it because it grips the cloth and pull fibers out of it.

I do still have the other side of the engine, maybe ill try the S100 just to rule it out.

 

Ya... Maybe the order got screwed. The two pictures facing the derby cover look good. The other two (showing on the left and right in my browser) look dirty.

Wonder how many times you could attempt this method with out completely removing the finish?

 

My thoughts are that you wont be able to scrub many times. The finish isnt insanely thick.
But... Once the rough portion is scrubbed off, I can actually wipe the engine with a cloth. Its very smooth.

Now that its not so rough, I'm thinking it wont stain nearly as easy. Dont quote me on this as its only been done a few days. Comparing it to spilling a drink on a rug VS hardwood. Should "in theory" not stain as easily, or at least be easier to wipe away.

Not saying this is the absolute only way of cleaning the engine, just sharing my experiences and battle of getting the grey engine show worthy. My Nightster is an 07 and I've only owned it a few months, but know that it had been far and few between details. Had to get that engine clean at any cost.

 

Hey thanks for the idea!
Question is, why do you mean by scour pad? As in what kind of grit/abrasiveness? There are scotchbrite pad that I can use on dishes, and some that can literally bowl out steel, so I was just curious about what kind of product you were using.

 

A scotchbright pad is exactly what I used.

 

My engine casing is smooth(ish) now, not gritty like the factory finish. Much, MUCH easier to clean.