- Joined
- Jun 30, 2012
- Messages
- 13,658
I think it is the matter of a dog chasing it's tail, with conventional carburettors. The vacuum operated slide in the SU carb is probably no better than the constant velocity systems which were used on many Japanese bikes. The shape of the needle still determines throttle response by compensating for loss of vacuum. What we need is perfect mixture and ignition control under all operating conditions - as the vacuum in the inlet tract changes.
I suggest the reason that most modern bikes of simiar capacity to Commandos are faster, is due to this factor. The Royal Enfield retros have fuel injection, but probably not a fully integrated engine management system.
However in saying that - I would not fit a black box onto a classic Commando, where it could be seen. Anything non-original de-values the bike.
Many years ago I met a guy ( Baldo Meli) who had worked for the Triumph factory. He was responsible for the crank in my short stroke Triton 500. He was a mad Irishman who had got a 12th in the IOMTT in about 1948 on a rigid-framed Tiger 100. I always thought he was an idiot, so I never believed his bullshit. He said 'SU carbs are good'. A lot of what he brought to Australia in the early 1950s appeared on later model Triumphs. The Bonneville head was one of his achievements. And the 5TA had a 65,5mm stroke, where the one he created was 63mm stroke. That 500cc Triumph Percy Tate raced was short stroke.
When I think about what he had said, in hindsight - he was always right and I was ignorant.
I believe fuel injection was first used in Hitler's racing cars and then in the FW190, With petrol, in particular - the slightest bit too rich and the motor will be slow. You cannot be obliged to adjust the carburetor every time you ride the bike.
I suggest the reason that most modern bikes of simiar capacity to Commandos are faster, is due to this factor. The Royal Enfield retros have fuel injection, but probably not a fully integrated engine management system.
However in saying that - I would not fit a black box onto a classic Commando, where it could be seen. Anything non-original de-values the bike.
Many years ago I met a guy ( Baldo Meli) who had worked for the Triumph factory. He was responsible for the crank in my short stroke Triton 500. He was a mad Irishman who had got a 12th in the IOMTT in about 1948 on a rigid-framed Tiger 100. I always thought he was an idiot, so I never believed his bullshit. He said 'SU carbs are good'. A lot of what he brought to Australia in the early 1950s appeared on later model Triumphs. The Bonneville head was one of his achievements. And the 5TA had a 65,5mm stroke, where the one he created was 63mm stroke. That 500cc Triumph Percy Tate raced was short stroke.
When I think about what he had said, in hindsight - he was always right and I was ignorant.
I believe fuel injection was first used in Hitler's racing cars and then in the FW190, With petrol, in particular - the slightest bit too rich and the motor will be slow. You cannot be obliged to adjust the carburetor every time you ride the bike.
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