All of the tires on my trailers are balanced. That's 4 trailers, two are tandem axles two are single, so that's 12 tires that are available to "go check"... This afternoon when reading this thread, I decided to "just go take a look"... Every one of my tires has less than 3 ounces (on the inside and outside combined). With that observation, I thought that 9 ounces seems like a lot, maybe even too much weight to balance a tire... So, I went to Google and asked the question. One of the sources that came up was Tire Rack.com. According to that website, a professional tire company website, they say that an acceptable maximum amount of weight should not be more than 1% of the wheel and tire weight.
http://blog.tirerack.com/blog/make-d...-are-too-many-
So, for "grins" lets assume that the OP's wheel weighs 35 pounds and the tire weighs 35 pounds. That's a total of 70 pounds or 1120 ounces (70x16=1120). One percent of 1120 is 11.2 ounces. So, according to Tire Rack, 9 ounces of weight would be acceptable..... If the OP's tire/wheel assemblies weigh more or less than the example, then the calculations would need to be done with his actual tire/wheel weight. The 70 pounds I used is just a "guesstimate".....
I believe that I'd do two things, first, look on the inside of the wheel AND the outside of the wheel, add up the total amount of weight and second, look at the dots on the tire to make sure the yellow dot is aligned with the valve stem.
Now, one other consideration that Tire Rack doesn't address and that isn't discussed by the OP is whether he has a TPMS system. If he has an external TPMS screwed onto the top of the valve stem, it weighs about 1.5 to 2.5 ounces and if it was on the tire when they balanced it, well that would mean that the actual tire balance only needed 9-1.5 or 7.5 ounces... Maybe even as little as 6.5 ounces. To me, that still seems like a lot of weight, but according to Tire Rack, it's within acceptable limits.....