Forum

[Thack]

MartinB, you wrote: "I spent a small fortune on my Electra X putting on an Amal Carb and timing adjusters for very little gain so did not want to repeat that!" I expect this comment will be removed, but frankly I've always been surprised that Hitchcocks sell Amals at all. Even in their day they were regarded as very poor compared with their more sophisticated Italian and Japanese competitors (and trust me I know - I've had a lot of experience with Amals back in the day). Progression off idle is a particular weak point with the Concentric, with a flat spot just as you crack the throttle very common. If you plot fuel flow vs air flow they generate a very bendy graph with wide mixture variation. Their main advantage was that they were much cheaper than the others, and because pretty well every Brit bike for decades had them fitted you could buy replacement parts from any motorcycle parts shop in the land. Personally I wish our hosts would sell Dell 'Orto pumpers!

[Thack]

Before I get thrown out for criticising Amals, I wanted to say "thank you" to everyone who commented in this thread. I'll be having a chat with Haywards of Cambridge in the next few days! Thanks again.

[trevorch]

Dear Thack,

With my 2011 EFI I fitted the short Hitchcocks silencer(91080), that retains the existing down tube. With the internal baffles in place, the sound was fantastic. Increase in power was minimal, but no effect on the throttle response or fuel consumption, still very good around 3.5L/km. Also fitted one tooth larger pinion. Changing back to a conventional carb of any make, together with removing the heavy cat. silencer is pretty sure to worsen fuel consumption and create an illegal level of emissions IMHO. The existing ECU can surely be tweaked with a power commander but this would only be worthwhile for more extreme silencer and air filter modifications. Cjheers TrevorCH

[Presto]

I don’t understand criticism of AMAL Mk 1 carbs. They have been used very successfully in every type of motorcycle application – touring, sports, road racing, trials, moto-cross, grasstrack, enduro, etc., etc. They work well in four strokes and two strokes. They are not the ‘best’. They certainly are not the ‘worst’. They are easy to tune and give good service for little outlay. Most of the ‘problems’ are down to user mis-tuning and rider mis-use!

[wilf]

Trevorch, did you out want to revise your fuel consumption figures?

[trevorch]

Wilf, thanks. Of course 3.5L/100km

Cheers Trevor