Single Carburettor

Hi Graham,

Smaller carburettors are a lot easier to calibrate for good idle and smooth progression from idle as the gas speed is greater. Personally, I would expect there to be an undetectable power difference (caveat - both carbs being properly jetted) between the two carbs until the engine was north of 5000rpm.

When the Ducati 900 was a current model (late '70's) I got to ride both a 900SS and a Darmah on the same day.

The Darmah was by a long way the nicest of the 2 to ride - not talking ergonomics or comfort - as it 'drove' so much more easily at normal speeds and especially around town. The Darmah had 32mm carbs, the SS 40mm. 

Hope this helps your decision,

George

I fitted a 34mm single Mikuni to my Mk3 around 20 years ago. I have done around 80,000 miles with the carb needing little attention. I was advised at the time that a 36mm carb would increase the petrol consumption but would make little or no difference to the useable power other than at the top end in 4th gear.

Hi Tim,

Was that attention late August 2017 on Olivers Mount, Scarborough and fixed by the Great Late Mark McLennon? I seem to remember the carb coming loose and you had to manually richen the mixture to keep going. I have the photo. Treasured memories.

For me, my Mk 3 Commando runs very well on a single 32mm Mk 1 Amal.  (68 mpg) E0 petrol.

I run a VM 34 with the 2-1 manifold cleaned up to blend with the ports and the largest K&N filter that would fit in. Running with a PW 3 cam, good for road speeds but probably looses out at top speed on a track. Pulls strongly low and mid range and uphill.