Painting the engine

CMA_Decky

New Member
Dec 6, 2008
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North SF Bay, CA
Well I finally got my chinese two stroke mounted on my frame. Luckily in all my college wisdom I chose the cheap shoddy looking old mountain bike frame. Anyways, I'm repainting the frame satin black this weekend and was thinking about painting the crankcase red. I have the red ceramic engine paint which is good up to 500 degrees (or so it claims).

Does anyone have any tips on painting the crank case? Will the paint even adhere or is it just going to chip off. Maybe I should stick to just the drive sprocket and clutch covers?
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
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No need for special paint.

Clean the parts to be painted with MEK, acetone, or laquer thinner thoroughly.

After it's dry, use an etching primer for added security, and then paint away with whatever you have.

I have use Rustoleum (o.k.) and Krylon (very good- even on the exhaust...after the first 4") and walmart spray paint (O.K.)
 

wheelbender6

Well-Known Member
Sep 4, 2008
3,988
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Sometimes painting just the removable engine covers looks great. You might try that first and see if it gives you the look that you want. LOL
 

CMA_Decky

New Member
Dec 6, 2008
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North SF Bay, CA
I was thinking about painting the crankcase and covers with the red-orange engine paint. I'd like to see if I could get a rediculous rat rod look (the bikes painted matte black).
 

sojudave

New Member
Oct 18, 2008
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austin tx

wheelbender6

Well-Known Member
Sep 4, 2008
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Orange was once the color of Chevy high performance engine blocks, as late as 1978. That's a definite ratrod color!
 

eDJ

Member
Jul 8, 2008
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If anyone here goes to clean parts with those solvents Bikeguy Joe mentions and doesn't have much experience with them....do try to do it outdoors in a well ventelated area. I've worked with the MEK (Methal Ethyl Keytone) which is an inorganic solvent and "wicked" on one's lungs. The others are bad enough. The vapors are dense and linger on the ground and can build up on the floor of a closed garage in the winter.

Once my Dad and I were working in the garage and we were up on this pontoon boat deck we were building. Grandma's ol wiener dog was on the floor curled up by the gas heating stove as we started cleaning metal work with the acetone. We heard funny noises and it was the wiener dog with her nose in the crack at the bottom of the door huffing for fresh air. We simply forgot about her being there and the vapors. Dad and I were up higher and it didn't notice but it only took a few minutes to pickle the pooch.

Just a heads up.

I've learned that when working with aluminum and you want paint to stick to it.......using a mixture of "Lye" mixed in a strong solution with water and appied to the metal, it will create micro pits on the surface that the paint will hold to. It will be nearly impossible to ever get it off once painted on.

Another process for coloring aluminum is to anodize it. This is a process of dying aluminum. I think it could lend itself to the covers of the motor as well.
I have a book around here titled, "Formulas Methods, Tips, and Data that gives instructions on anodizing aluminum. The internet abounds with information on doing it too.

Basically:

The first thing to do is to get the following things together: First on the list is the most expensive item: a 6 to 12 volt battery charger. They run from $45.00 to $110.00 depending on model, functions, etc.(The next item, though not that expensive, will take some effort to find: battery electrolyte, a.k.a. sulfuric acid. This should be available at a battery wholesaler for about $2.00/gal. To make the negative ground, you will need some aluminum ground wire and aluminum-foil. The wire can be found at an electronics store for about $35/spool, and you should have the foil in the kitchen. If you happen to be out of foil, you can pick up some more at the store when you go to buy the last item for this project. No super-special chemicals or solutions necessary to make the colors; just plain-old fabric dye. (Something like Rit dye, for about $5.00.) Rit offers something like 30-40 different colors, so you have quite a number of choices for what color you want your parts to be. An optional item is nitric acid: about $25.00/2.5 L. (This is used to clean parts prior to anodizing, but there are some cheaper alternatives. See end notes.) This is available at chemical supply stores. Should you not be able to find any, you can try to get on the good side of the high school science teacher. He may help you out since you only need a few ounces
Be careful with Nitric acid coming in contact with copper !

A solution of 1-2 ounces of nitric acid in a gallon of distilled water will allow you to clean the surface in preparation for the anodizing. Aluminum oxidizes very quickly when exposed to air, so the easiest way to keep it clean is to clean it just before you are ready to start working on the piece. (You should rinse the part with distilled water before you put it in the next acid solution.) Make your negative ground with the aluminum wire and foil. Shape the end of the wire into a paddle shape and cover the round part with the foil. What you want to do is create a flat, round shape to sit on the bottom of the bucket, with a lead that comes up out of the bucket. You will clip the battery charger's negative lead to the wire that comes out of the bucket. When you are ready to start, you will want to mix up your immersion solution. In your rubber bucket, combine the sulfuric acid and water to come up with a solution that is about 30% water. (1 part water to 2 parts acid.) Place the paddle in the bucket and attach the negative lead. Then attach the positive lead to the part, making it an anode, and immerse it in the solution. (Remember that thetwo leads the paddle (cathode), and the part (anode) should not touch.) This is the best time to turn on the charger: once the part begins to fizz, leave it in there for about 10-15 minutes. After about this time the part should no longer conduct electricity. (You can also use an ohmmeter to check conductivity, but this is not needed.) Turn off and disconnect everything, and rinse the part in cold water.
Read more about it here:

How To Anodize All Your Aluminum Parts - ThirdGen.org
 
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Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
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Los Angeles, CA.
Why's that? Is it because they are easier to deal with? 2 strokes are definitely cheaper.
There are many reasons I prefer the 2-strokes... they ARE cheaper, they have more torque, they have fewer parts to break, I like that they have a real clutch (not a centrifugal), they look like real motorcycle engines, they have engine braking, the gear boxes in the 4-strokes suck!, you never have to check your oil, the list goes on!!
Probably the main thing with me is that they look soooo much cooler than all the other engines out there! (looking cool is very important!) :D .boogy1a .fly
 

sojudave

New Member
Oct 18, 2008
189
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austin tx
There are many reasons I prefer the 2-strokes... they ARE cheaper, they have more torque, they have fewer parts to break, I like that they have a real clutch (not a centrifugal), they look like real motorcycle engines, they have engine braking, the gear boxes in the 4-strokes suck!, you never have to check your oil, the list goes on!!
Probably the main thing with me is that they look soooo much cooler than all the other engines out there! (looking cool is very important!) :D .boogy1a .fly
No doubt. But I was looking at a 4-stroke kit, and other than the red cover, they don't look to bad. Those can probably be removed or painted, pinstriped or whatever. The two strokes do look better and I am used to a clutch too. I had a chance to cruise on a 4 stoke and dug it pretty well. My current proj has changed quite a bit due to donations. I got a chicks mt bike, and three weedwacker motors, so I got some figuring out to do. Been reading Deacon's posts for clues and pointers and what not. I think I'm gonna mount it low and use a chain, keep the clutch til it blows up.
 

jasonh

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Jun 23, 2008
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they have engine braking,
Only problem is engine braking really isn't the greatest for a 2-stroke, especially at high speeds. When that throttle snaps closed, you're not getting as much oil as you need for the higher rpms that the motor will still be turning.

But yeah, the 2 strokes are great. Never have ridden a 4 stroke though.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
235
63
up north now
Only problem is engine braking really isn't the greatest for a 2-stroke, especially at high speeds. When that throttle snaps closed, you're not getting as much oil as you need for the higher rpms that the motor will still be turning.

But yeah, the 2 strokes are great. Never have ridden a 4 stroke though.

Good point about oil starvation.

I HAVE "ridden" a four stroke- outboard....my Briggs and Stratton 4 T outboard is THE BIGGEST P.O.S. there is.
 

sojudave

New Member
Oct 18, 2008
189
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austin tx
rotfl

Went from best way to paint to 2 vs. 4 stroke.
Well to get back on topic, here's what I would do:

Take the engine out of the bike (if it's in there).

Take the covers off (clutch, crank, and generator) and remove the gaskets. Also take off your exhaust and gasket.

Spray the covers with Auto strip or Aircraft remover. Then spray the engine with the same stuff. This will remove the gray paint or whatever is on the chengines. Let the stuff get dry and flakey. Have a beer, or chill out for a while.

When it's dry and flakey, hit every part with a drill and wire wheel to knock off the flakes. Anything else sand off or respray. After this is done, take a damp cloth and wipe everything you sprayed thoughoughly.

Go to an auto parts store or wallyworld and buy engine paint with ceramic. This is fuel and heat resistant. You don't necessarily have to primer the stuff but it may help. There's no need for clear coat unless you want it.

When you spray the parts, hold the rattle can about 4-6" away from the part and do several light even coats. Let each coat dry, have a beer or chill out or whatever, and do all over again and again until it is all covered.

Put everthing back together.

If you want to do some custom stuff. Then after the parts are stripped, take a sharpie and draw your design on your covers or whatever, then use masking tape to tape off the section you don't want, let's say black. Then spray the whole part black, the same way I stated above.

When that's good and dry, remove the tape and then tape over the sections you painted black. Spray the new section with red or blue or whatever. Repeat the same process as above. When that's dry remove the tape and lightly sand the borders to help erase the lines, then you could get some adhesive pin striping to cover the border, or paint the pin striping on. If you use the adhesive type, then spray everything with a couple coats of clear.

Everything can be done with rattle can. If you want to use conventional spray paint, be sure to primer and cover with automotive clear, because grease, gas, and heat could and will damage your paint job.
 

jasonh

New Member
Jun 23, 2008
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in regards to the custom stuff, it'd probably be easier to just spray the lighter color, then tape off whatever design you want to stay that color, and spray with your darker color.

Less taping, easier to get it nice.
 

sojudave

New Member
Oct 18, 2008
189
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austin tx
in regards to the custom stuff, it'd probably be easier to just spray the lighter color, then tape off whatever design you want to stay that color, and spray with your darker color.

Less taping, easier to get it nice.
my only thing would be that the paint would feel uneven you know? The darker color would be raised up. Do you have an idea on how to get around this?