Carb Corrosion

[b7labelle]

Sooo the lawn mower saga continues for those who saw my other post.

Today I reassembled the Nikki carb for my B&S 44M777, and noted a lot of corrosion had returned to the previously cleaned surface. Apparently this is zinc oxide, and the protective coating on my carb is thin or gone.

I had cleaned the carb in a ultrasonic cleaner with some Simple Green D Pro 3. Before it went in the cleaner, the carb looked relatively clean, and I don't recall any corrosion. Maybe the surface had corroded, but was smoothed by constant air/gas flowing through it.

2 questions:
1) Did I F my carb by cleaning it with a ultrasonic cleaner and some Simple Green? I see this is a pretty common practice, so this is doubtful. I didn't do any surface scrubbing that would have etched off any protective coating.

2) Is this carb usable? The corrosion built up this afternoon to where I couldn't move some of the linkages, but now that they are broken free they seem to move ok. I'm more concerned about corrosion blocking internal passages. Should i just cut my losses and order a replacement chinese carb?


A similar result happened with my pressure washer carb after going into the ultrasonic cleaner with Simple Green D Pro 3

 

[MFolks]

Are you using any of the "Gasohol" in the mower? It will attack most carbs,the large boating industry got a waiver to exclude use in their boats, as it would attack the fiberglass tanks. Silicone gas lines seem to work the best,as rubber ones may swell internally,blocking fuel flow,not seen outside the hoses.

 

[b7labelle]

I’ve made it a point to use pure gasoline in the last few years, but this mower has seen ethanol. I didn’t see any signs of jelly when I took it apart. No white dust either

 

[MFolks]

If it were me,I'd have a spare carb,unless your going to sell the mower.I see the linkages binding again soon.

 

[DTE]

Curious, why would you not buy a gallon of carb cleaner to soak it in ?

 

[b7labelle]

The carb is clean and the oxide can be stripped, it just re-oxides when it dries.

 

[J.C.]

What was the ratio of simple green to water that you used? How long did you leave it in the ultrasonic for?

 

[b7labelle]

About 1:1, maybe an hour or so

 

[DTE]

Simple greens website says unprotected aluminum should not be soaked longer than ten minutes. https://simplegreen.com/faqs/ But I still soak carbs in carb cleaner. My experience is all those type cleaners, green purple whatever are caustic on soft metals.

 

[J.C.]

I use less than 1:10 and don't leave the carbs in for more than an hour at a time else they go grey and furry, kinda like what you're seeing there. I'm pretty sure 1:1 for an hour would cause surface corrosion/oxidation/whatever it is.

 

[SGKent]

the zinc or aluminum oxide is a result usually of moisture. Is the mower in a damp place? try cleaning it with a dry green pad, blow it off well and spray it with WD-40 The WD 40 will displace the rust for awhile.

 

[b7labelle]

Well the thing rusted up overnight. I think what I am going to do is pick up a non-water based cleaner, let it soak to remove the oxide, then air dry them and coat with wd-40 and see if that prevents moisture from rusting it to shart

 

[EOC_Jason]

The ingredients in the "Pro" Simple-Green are totally different than the Original / Plain stuff... They are corrosive & toxic, whereas the regular isn't...

 

[redmondjp]

Unless this corrosion is affecting the carb's performance, I wouldn't worry about it. I live if a moderately-humid climate, and this surface corrosion appears on just about every piece of equipment that I have, especially on equipment that stays in unheated storage in detached buildings.

 

[b7labelle]

Unless this corrosion is affecting the carb's performance, I wouldn't worry about it. I live if a moderately-humid climate, and this surface corrosion appears on just about every piece of equipment that I have, especially on equipment that stays in unheated storage in detached buildings.

That's basically where I'm at. I'm going to reassemble when my last parts arrive and check it in at the end of the season, assuming there are no immediate issues. If it's running okay, and the corrosion isn't out of control, I'm going to ignore it.

 

[b7labelle]

Got the mower put all back together, runs much better! There is some slight surging at idle, so I am going to replace the fuel lines/pump/filter and breather tube and see if that takes care of it.