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‘80 CX500C German (not running) and an ‘18 Yamaha Mt-07
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Discussion Starter · #1 ·
Hi everyone, I purchased Larry's Carb book a few months back and began cleaning my carbs. Based on his recommendation I purchased an ultrasonic cleaner and started ultrasonic cleaning my carb bodies. Life became busy and I am just now getting back around to finishing the carb cleaning. I have run into an issue with one of the carbs in which the body has formed a white oxidative layer all over and I have run it for 2 hours today with no sign of it coming off. The other carb is dark after its first cleaning months ago and i expect that it will do the same thing if I ultrasonic clean it. Does anybody have any experience with removing this white oxidation layer post ultrasonic cleaning (images of oxidation I am discussing below)?

For clarification, the oxidated carb was put through 2 cleaning cycles months ago in which I expected it to be clean after the second but instead it had the oxidative layer so I left it to deal with when I wasn't so busy. Thanks for yalls help as always!

Edit: The darker spots on the carbs are where I tried to scrub off the oxidation with little to no success.
 

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What solution are you putting in the sonic? And at what ratio?
 

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‘80 CX500C German (not running) and an ‘18 Yamaha Mt-07
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Discussion Starter · #5 ·
I've had that happen some years back. I can't remember why.

The only solution that I found was to polish the carbs with steel wool and autosol.
Is there anyway that you found to clean out the insides of the carbs? Im afraid that even if i remove all the oxidation from the exterior the ports would still be gunked with it.
 

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Is there anyway that you found to clean out the insides of the carbs? Im afraid that even if i remove all the oxidation from the exterior the ports would still be gunked with it.
I believe I dunked them in white vinegar briefly but don't remember for sure.

Be sure to neutralise the vinegar immediately in a water and bicarb soda solution if you try this. Vinegar will flash rust steel parts like butterfly shafts in short order.
 

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Im using Zep Purple degreaser because none of the stores around me have simple green hd. Ratio of about 1:8. Could that be the issue?
Absolutely that's your issue! Zep purple is very corrosive to aluminum. It even attacks/dissolves and stains the anodizing on aluminum. When I get a set that's been done like this, I have to seal up the body and vapor blast them to get the film off the outside. Try Marks suggestion above and see if it cleans it up. Good luck with the rebuild.
BTW, when you can't get the suggested cleaner, just use Dawn dish soap. It works wonders and does not leave a film or corrode any surface. Think about it, we eat off things washed in it!
 

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‘80 CX500C German (not running) and an ‘18 Yamaha Mt-07
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Discussion Starter · #8 ·
Absolutely that's your issue! Zep purple is very corrosive to aluminum. It even attacks/dissolves and stains the anodizing on aluminum. When I get a set that's been done like this, I have to seal up the body and vapor blast them to get the film off the outside. Try Marks suggestion above and see if it cleans it up. Good luck with the rebuild.
BTW, when you can't get the suggested cleaner, just use Dawn dish soap. It works wonders and does not leave a film or corrode any surface. Think about it, we eat off things washed in it!
Well I’ve just learned purple degreasers are not all the same grade. Yikes. I should have done proper research!
 

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1983 cx650c
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Yes, detergent is the best in a sonic cleaner. Purple power caused me grief and time on polished aluminum just cleaning the bike. I'd say the 0000 steel wool and light oil is good for surface restoration on what you can touch, not entirely sure about internal passages but vinegar dip and soda dip with hot rinse and more light oil after may help. Then another sonic bath with dish detergent,,? Most chemical degreasers say something on container about reactions that may occur, I read it after it filled my polished aluminum,,,
 

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I restored a cb750 that the left carb float bowl (sitting on side stand for years) was completely full of white corrosion, float pivot parts gone,, that carb was not salvageable but the other three cleaned up and with a different carb the bike ran pretty good. Not sure what they put in that gas tank to "clean" the fuel system, but it didn't work. Minor surface corrosion is a small problem. Test passages for function with spray carb cleaner during cleaning process.
 

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During your resto....always remember time is your friend... start with the less "abrasive" and work your way up....on pretty clean components many use deionised water....Marks suggestions are also a good way to get a good result
Same applies for stuck bolts....good penetrant then revisit it in a day or two. .
 

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I use dawn in the ultrasonic and am pleased with the results. I even use it when working on other stuff like cleaning the rust inhibitor off of new brake rotors instead of brake clean, works wonders and isn't harsh on your hands. Dawn is my new best friend! :p
 
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I use dawn in the ultrasonic and am pleased with the results. I even use it when working on other stuff like cleaning the rust inhibitor off of new brake rotors instead of brake clean, works wonders and isn't harsh on your hands. Dawn is my new best friend! :p
And as opposed to "break clean" wont eat through most workshop gloves....and less toxic....
 
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