ZAMA carb warning....
10-28-2010 | 07:32 PM
#1
ZAMA carb warning....
I could make this a long story, but I won't. Suffice to say that I am fixing a big load of yard equipment to sell, and grabbing some good engines for myself, and today I learned something. Spray carburetor cleaner will damage the one way valves in the primer pump on Zama carburetors, and make them unuseable. It must melt some tiny plastic piece inside the valve or something, but after being blown out with carb cleaner, within seconds the valve will no longer flow. No way to fix it either.
I was using "Gumout" carb spray, but I bet most carb cleaner sprays that work well would cause the same problem.
Just thought I would share the "find", and maybe save someone some grief!!
Ok, I'll admit it; I ruined several primer pump assemblies before I figured out what was going on...
AV8TOR
I was using "Gumout" carb spray, but I bet most carb cleaner sprays that work well would cause the same problem.
Just thought I would share the "find", and maybe save someone some grief!!
Ok, I'll admit it; I ruined several primer pump assemblies before I figured out what was going on...
AV8TOR
10-28-2010 | 09:16 PM
#4
RE: ZAMA carb warning....
Chlorinated hydrocarbons like trichlorethylene, which I have used in carb and brake cleaners will attack some plastics like polycarbonate (Lexan).
Aliphatic hydrocarbons like mineral spirits, Varsol, naptha ususally will not harm most plastics, but will attack silicone rubber.
Aromatic hydrocarbons like acetone, tolulene, and MEK attack most plastics except polyethylene and teflon.
Most alcohols are safe to use with most plastics, but attack some rubbers.
The safest cleaner would be the fuel that is used with the carb. I use Coleman camp fuel which is basically like naptha for my gas carbs, and speed shop methanol for my glow carbs. I use both, with oils added, as fuel also.
Good luck.
Sincerely, SPACEWORM, Saito Club #635
Aliphatic hydrocarbons like mineral spirits, Varsol, naptha ususally will not harm most plastics, but will attack silicone rubber.
Aromatic hydrocarbons like acetone, tolulene, and MEK attack most plastics except polyethylene and teflon.
Most alcohols are safe to use with most plastics, but attack some rubbers.
The safest cleaner would be the fuel that is used with the carb. I use Coleman camp fuel which is basically like naptha for my gas carbs, and speed shop methanol for my glow carbs. I use both, with oils added, as fuel also.
Good luck.
Sincerely, SPACEWORM, Saito Club #635
10-28-2010 | 10:32 PM
#5
RE: ZAMA carb warning....
W8ye, that's true, but these carbs are on gas powered equipment that I am selling to people, and they have to work properly.
I avoid using Zama carbs on airplane engines, due both to the lack of documentation on them, and the high cost of repair parts. Sometimes I use them and they work alright most the time, but given a choice, I put a Walbro on.
Sometimes the deposits in carbs that have sat unused for some time are very difficult to clean/remove without an agressive solvent like carb cleaner. This is the first time in many years of using it that I have had any problems. At first I thought tiny pieces of dirt were getting into those one way valves, but then I did a test, and sure enough, the carb cleaner ruins them... Live and learn!
AV8TOR
I avoid using Zama carbs on airplane engines, due both to the lack of documentation on them, and the high cost of repair parts. Sometimes I use them and they work alright most the time, but given a choice, I put a Walbro on.
Sometimes the deposits in carbs that have sat unused for some time are very difficult to clean/remove without an agressive solvent like carb cleaner. This is the first time in many years of using it that I have had any problems. At first I thought tiny pieces of dirt were getting into those one way valves, but then I did a test, and sure enough, the carb cleaner ruins them... Live and learn!
AV8TOR
10-29-2010 | 07:43 AM
#6
RE: ZAMA carb warning....
Maybe either the solvent in the carb cleaner or the plastic in the valve has changed. Chlorinated hydrocarbons have been banned in a lot of cases and other solvents substituted for them in carb and brake cleaners. Maybe the can label can tell you what solvent it is that is causing problems and try aother solvent class. Or, maybe "cook" the parts in antifreeze in a crock pot?????? I have not tried to AF so try it with a bad valve first.
Good luck.
Sincerely, SPACEWORM, Saito Club #635
Good luck.
Sincerely, SPACEWORM, Saito Club #635
10-29-2010 | 08:49 AM
#7
Senior Member
My Feedback: (19)
RE: ZAMA carb warning....
There are all kinds of carb and brake cleaners. The MSDS for Gumout carb cleaner shows MEK, so that's probably what did it in. Viton doesn't play well with MEK. I try to pick cleaners that don't have the nasty stuff in them. I found a brake cleaner that's glow engine compatible and used it to flush silicone parts without a problem. Usually the ingredients are right on the can so you can check at the store.
11-04-2010 | 07:21 AM
#8
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From: , GA
RE: ZAMA carb warning....
ORIGINAL: av8tor1977
I could make this a long story, but I won't. Suffice to say that I am fixing a big load of yard equipment to sell, and grabbing some good engines for myself, and today I learned something. Spray carburetor cleaner will damage the one way valves in the primer pump on Zama carburetors, and make them unuseable. It must melt some tiny plastic piece inside the valve or something, but after being blown out with carb cleaner, within seconds the valve will no longer flow. No way to fix it either.
I was using ''Gumout'' carb spray, but I bet most carb cleaner sprays that work well would cause the same problem.
Just thought I would share the ''find'', and maybe save someone some grief!!
Ok, I'll admit it; I ruined several primer pump assemblies before I figured out what was going on...
AV8TOR
I could make this a long story, but I won't. Suffice to say that I am fixing a big load of yard equipment to sell, and grabbing some good engines for myself, and today I learned something. Spray carburetor cleaner will damage the one way valves in the primer pump on Zama carburetors, and make them unuseable. It must melt some tiny plastic piece inside the valve or something, but after being blown out with carb cleaner, within seconds the valve will no longer flow. No way to fix it either.
I was using ''Gumout'' carb spray, but I bet most carb cleaner sprays that work well would cause the same problem.
Just thought I would share the ''find'', and maybe save someone some grief!!
Ok, I'll admit it; I ruined several primer pump assemblies before I figured out what was going on...
AV8TOR
] Although in my case, they didn't work the next day when I went to show my brother the problem...
