Bubbles in fuel line. Would Bubbleless Clunk help?
 

I have noticed that on full throttle I get bubbles in my fuel line which appears to cause very minor sputters in the engine (.46 glow). Is this normal and would something like the O.S. Bubbleless clunk help?

Bubbles in the fuel are most often caused by excessive engine vibration. You may have a propeller out of balance, or rare cases, a bent crank. If this is the case, a bubble-less tank will not help much. You may also have an air leak under your carb or backplate.
I've never had an issue with regular 2 line fuel tanks when the fuel tank is padded and the prop was reasonably balanced. Your problem may disappear with an inexpensive new prop.

In the boating world, it's normally a pinhole in the line or a loose fitting line at the tank outlet that causes bubbles.
I'd check the fuel supply line first, then the prop balance as suggested above and, if they are all good, I'd look at replacing the pickup parts inside the tank as you might have a cracked brass tube or torn hose between the tube and clunk

I don't think so. Depends on where the bubbles are coming from I'd say you have an air leak. Look carefully at the needle valve are the bubbles between the tank and the valve? If so fill the tank if the bubbles go away your pick up line is leaking inside the tank. If the bubbles are after the valve your valve is leaking, easy fix with an o ring.
If the bubbles aren't from the tank but are before the needle valve check the line to the carb, especially where it passes through the fire wall.
Do you have one of those fancy fueling valve? They like to leak air.
Good luck let us know what you find

It's an Evolution engine, so the needle valve is towards the back and then there is a fuel line between the needle valve and the carb. I notice these tiny bubbles between the needle valve and carb.

The O-ring on the remote needle valve may be leaking. I couldn't find just the O-ring, but the entire remote assy is fairly inexpensive. It might be worth a shot. https://www.wholesaletrains.com/Detail.asp?ID=200432171

The reason I mentioned excessive vibration in my earlier post is you said you don't get the bubbles below full-throttle.

I had the same problem with an OS 40 LA not too long ago. Turns out the o ring in the needle valve had worn out. I ordered a new needle for about ten bucks and the problem was solved.

I happened to run into the same problem today, it turned out to be the tank stopper became loose. It was on a tower trainer when i assembled it i didn't over tightened the stopper because i tend to tighten so much that it split the Chinese tank.