TR4/4A TR4 HS6 carb float bowl lid orientation

[Adrio]

Does anyone happen to know if the orientaion of the float bowl lid on the bowl of the HS6 carb is significant. I notice that the lid can go on in any of three positions. But given that the engine is slightly nose up and the front and rear carbs are mirror images, I was wondering if there is a "correct" way of putting the float lids on.

While trying to figure out my backfire problem, I noticed that the front carb has the fuel level higher then the rear carb. No amount of float level adjusting seems to change this. In fact adjusting the float level seems to hardly change the fuel level. I have checked and verified the float, the flat needle and seat and they are working fine.

I am grasping at straws but thought this might be significant and I hope someone knows if this orientation is significant.

 

[gbtr6]

You could try different positions. I adjusted mine for ease of mounting the fuel lines. Also, try the Grose jets. They help. Perry

 

[piman]

Hello Adrio,
the orientation is irrelevant, just set them to suit the fuel lines. There are, I believe, three different floats that were used in HS units, Brass - 5\16" setting, plastic and metal arm - 1\8" to 3\16" and the later all plastic 1\16" to 3\16" so there is some variation. The latter are not adjustable in the normal fashion as there is no arm to bend, but what thickness washer that is fitted to the needle jet body can affect the fuel level.
How severe is the backfire, I take it you are talking about a backfire on the over run? It could be an air leak on the exhaust manifold\front pipe or some over fuelling perhaps from the carburettor(s) not closing with the throttle off (unlikely if it idles easily)If your units have the little poppet disc in the throttle plates, try sealing them off?

Alec