Hy Ron, thanks for your reply.

First of all, excuse my english, Im from Mexico, LOL, so Ill try to explain myself as clear as I can.

I found that the "carb Adjuster" is called the Carb Retainer, with O-Rings on both sides. One of those came broken, like a "C" shape. I just put another one, and fits a little tight, but nothig to worry about.

The second Issue is the carb not sitting flush to the block of the engine. Between the oring and the block, there's like 4mm. I pushed hard enough to the point my finger had marks of the restrictor.

Having that problem, I decided to open the box of my other new B5, to check if the carbs had to be that apart from the block, and my surprise was that the 2nd engine and the carb sit perfect, so I checked the 1rst carb with the 2nd engine and sits perfect. So the problem was the first engine.

I put both carbs in the first engine and they don t fit right (4mm upper than they should be).

I checked both carbs and are exactly the same dimensions. The white insulation plastic is exactly in the same position, flush to the alloy material.

So, I decided to remove about 2mm of the white material in the end of it (like a cone) with a hobby knife, after that, the carb sits perfect in the 1rst engine.

Hope I was clear enough, LOL.