Topic: Carb Cleaning Idea using Evap O Rust Product (similar to CLR)

[hondabbqman]

I'm starting on a 71 cb750 restoration.  Previously on a restoration of my 350f I sent the carbs away for complete ultrasonic cleaning and rebuild with mostly good results but the hassle of price and shipping.  I have a very knowledgeable friend on these bikes who will do this one (retired certified Honda mechanic from the 70s - knows his stuff).  Anyway, he does not have an ultrasonic cleaner.  When I was rebuilding the petcock on by cb350f I soaked it in carb cleaner for a good while, still had a bunch of caked on residue in it.  I had this Evap O Rust product (rust and lime remover) stuff so I thought it couldn't hurt to soak it in there for a day.  I will tell you the petcock came out looking about as good as an ultrasonic cleaning and the passages looked really clear - the stuff dissolved everything in there.  I was thinking it couldn't hurt to try it on my old carbs - I've not seen it hurt any other metals I have used it on.

Anybody have any experience with anything similar?

[bjbuchanan]

Evaporust is a pretty safe product to use for just about everything so I wouldn't be surprised if it worked to a certain degree. As for how well it works IDK personally. If it didn't eat a petcock, which it shouldn't anyway, then it won't eat the carbs. Similar type metal

I use xylene, leave them in that crap and it eats everthing. Get it on your hands and you know what i mean in about 3 seconds.

[KrautKoffin]

Evaporust is a pretty safe product to use for just about everything so I wouldn't be surprised if it worked to a certain degree. As for how well it works IDK personally. If it didn't eat a petcock, which it shouldn't anyway, then it won't eat the carbs. Similar type metal

I use xylene, leave them in that crap and it eats everthing. Get it on your hands and you know what i mean in about 3 seconds.

Xylene safe for carbs?

[bjbuchanan]

Yeah it is just a solvent/thinner. An unusual one for the most part but yeah it works great

[evanphi]

Follow the evap-o-rust/CLR with a good shot of compressed air.

[KrautKoffin]

I'll be soaking the carbs in these for a few hours.

[TwoTired]

If the pH of the your cleaning solution is on either side of 7.0, it will react with metal in a corrosive manner at a rate commensurate with how far away from 7.0 pH the solution is.   Chemical conversions do not happen instantaneously, small excursions away pH neutral will take longer to activate than large ones.  But, it happens nonetheless.

Evap o Rust is MSDS listed as having a pH:  5.7 – 6.3 making acidic and reactive to metals (dissolves metal).

CLR's MSDS states it's pH: @20ºC 2.10-2.30, making it significantly more acidic and active than Evap-o-rust.  It will dissolve metals faster by comparison.

I'm sure both will clean/dissolve surface deposits upon the metal.  And, when the protective deposits are gone (cleaned), the metal surface will be next to dissolve/etch/errode.

There are carb cleaners on the market which are pH neutral and also dissolve surface deposits.  These clean without risk the base metal.