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Moving The Carburettor

by

Nick Mohoney

Not wanting to cut the exhaust balance pipe on the front of the engine to be able to use the solex carburettor I thought I would try the approach Mike Bowden took and move the carburettor back to be under the bonnet. Cutting the branch pipes of the mainfold wasn't too difficult (Fig 1) but welding the manifold onto a support wasn't feasible for me simply due to not having a welder and not being able to weld if I did have one. So making use of the threaded studs protruding from the gear box case I managed to braze up and bend some rackets (fig 2) which allowed me to mount the carburettor partly over the gear box and partly over the starter motor using a combination of threaded rod and bolts and conical armour ring bolt covers to centralise the rod in the manifold assembly (fig 3 & 4) .The brackets felt a bit flimsy at first, but once bolted up on the gear box and manifold I found it was actually strong enough to pull the rolling chassis along by this mounting arrangement with no flexing or distortion.

I connected the manifold to the inlet ports using using fluro lined silicon hose and mounted the carburettor. It all fired up okay but,the silicon hoses collapsed gradually with the vacuum induced and caused the engine to stall.I bought some coil spring stiffeneers (fig 5) and put those inside the hoses and they seemed to do the job of keeping the shape. Covering the hoses with stainless steel braiding thankfully cut down on the lairyness of the hose colour. I didn't have the engineering skill of Mike to make up reversing levers for the throttle control, but by using generous curves on the throttle cable and choke cable (fig 6) I managed to get a reasonably a smooth action, helped by a stainless steel turnbuckle tension assembly from the front bulkhead onto the return spring ( fig 7). I had to do some adjustment to the gear lever on the splined spigot it sits on to avoid it colliding with the fueline but, the gear change seems fine.

How this lasts and performs long term, who knows!

Nick Mahoney

carburettor
carburettor
carburettor
carburettor
carburettor
carburettor
carburettor

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