Re-assembly questions

[bs175dths]

Any sort of guard used to protect the fuel line from getting damaged by constant use of the throttle linkage is going to reduce the amount of space between the moving part of the throttle linkage and the stationary fuel line to carburetor number 4.
Basically, the two will be rubbing each other when in use, and that means resistance.
Your throttle needs to snap closed when the throttle lever is released in all situations and in all rotating positions of the handlbars. It is a matter of safety!
Given the current availability of the fuel line in use, try trimming small amounts of tubing until sufficient clearance is achieved. Keep in mind not trimming this line too short.
If that doesn't work, locating the proper size fuel line may be your best (safest) bet.

BTW - the supplied photograph clearly shows the hose clamp closest to number 4 carburetor is tighter than its neighbor. Remember, that T fitting is plastic and they can be crushed by overtightening clamps. Backing off just a bit might be in order. Remember too, Mother Honda used those little, light duty clamps to hold the fuel lines. They have just enough pressure to hold the hose to the fitting and not cause a leak.

ps - I like to use a socket on a driver (not a rachet) to tighten these little guys, just until the excess band starts to curve.