I am transferring my dual carb setup (Weber 40IDF) from my ‘77 to my ‘78 (was shocked at how little room there is now…kinda wish I hadn’t started down this path). Anyway, I want to have the ability to run off the stock fuel pump - if and when I chose (as if the electric pump dies). I did find a single response on this site that suggested it has the output to keep up, so I’ll run with that. I’d also like to keep the fuel lines the same size, so here are my questions:
(1) the upper fuel pump manifold (not sure official terminology) is at least superficially different between the ‘77 and ‘78. Although I didn’t remove the hose from the ‘78, the hose barb is pressed into the housing. On the ‘77 the hose barbs are threaded (M8x1.25) and removable as shown below. Are these two manifolds interchangeable and use the same diaphragm? Is there a correct year per type?
(2) assuming there’s no issue swapping the two fuel pump manifolds, it sure would be nice to keep the 6mm fuel hose theme all the way through. The Webers have a fuel inlet hose fitting that is also threaded (M10x1.0) with an 8mm hose barb. I’ve searched high and low and can’t find a metallic (aluminum, brass or stainless) that offers a “proper” M10x1.0 to 6mm hose barb arrangement. At least that is available. Yes, there are several out there that have that call out, but NONE show a full flange/seat for the seal washer like a straight metric thread uses. The sad fact is that McMaster Carr DOES show it but all three options (brass/303/316) are not available. Surprisingly (to me anyway) Randakk doesn’t have it. Anyone have a source? I know I can cobble together a plumbing abomination but would like to do it clean. And I haven’t found a 6mm to two 8mm tee / y fitting either because that is just backwards.
(3) the other option would be to find an outlet fitting for the threaded manifold (M8x1.25 to 8mm hose barb). I’m having the exact same issue here as the flange/seat is insufficient for a proper seal. Besides, I’d rather go all 8mm including the petcock but I’m sure that’s a goose chase
Thanks,
Z
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