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Old 18th December 2020, 06:27
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Mister Towed Mister Towed is offline
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Issue with the HS2 carbs now solved. They weren't set too lean and everything was adjusted fine. The only thing I hadn't done was fit a breather 'Y' pipe from the rocker cover to the carbs, but that couldn't stop the engine firing, surely?

An internet search didn't throw up anybody who'd cited it as a reason for their engine not working, and the breather pipes on a MkIII engine are just tubes with no one-way valves in them so it made sense to me that running without them fitted would make no difference to the manifold pressure so shouldn't affect the running of the engine.

Despite not really thinking it would make any difference, I stuck some insulation tape over the breather tube on each carb, then, ignition on, press starter and Vroom! It worked.

So, for future reference the old Triumph Spitfire or Herald motor won't fire if the breather tubes are disconnected. Who could'a known?

Hoping to make some real progress now I have a working motor
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