Carb overflow pipes

[kettle738]

A while back there was an early CB750 on US ebay, I can't recall if it was a sandcast or later diecast K0, but an early bike nonetheless.

It was described as an unmolested example, and it looked it, pretty rough and dirty from standing so long, but seemingly very original.

I always scour the photos of such bikes for interesting detail, and what caught my eye was the overflow pipes from the float bowls, they were fuel stained brown, but they were quite obviously clear, not black.

It makes perfect sense to have clear overflow pipes on a four cylinder bike, so the leaking culprit can be easily identified.......but, should those hoses be clear or black?

I always thought they were black, but thinking isn't knowing, can anyone enlighten me please?

Mick................Kettle738

[Steve Swan]

I'm pretty sure float overflow tubes weren't used until mid-K0, they were black.  Not aware any sandcast fitted with these from factory.

[kettle738]

Many thanks for that Steve, but that's an even bigger surprise; it's amazing that Honda would fit overflow pipes to the carbs that are clearly made or at least able to accept a flexible hose......and then leave them bare to dribble on the crankcases.

Perhaps the owner of the ebay bike fitted them himself....it's hard to find detailed photos taken when these bikes were new.

Mine is a later K0 in any event, CB750-1010369 so I guess the answer is black tubes for me.

Mick..........kettle738     

[Steve Swan]

The February 1971 Parts List shows these overflow hoses used beginning vin 29794.  The hoses are not shown in the earlier CB750 parts lists.