Its an interesting issue. I have an ex demo bike and never had a problem to date, I must be one of the lucky ones! But I'll be honest, I wouldn't expect to "blip" the throttle at idle on a large displacement V twin and expect the idle to carry on like nothings happened! Hold the throttle for a second to let the engine speed advance well yes, but not a blip. That is different to an engine cutting out when you shut off the throttle during engine braking, or coming to a stop. When I accelerate I always rev the motor upto speed and slip the clutch. When I was a trainee engineer, a mentor told me never labour an engine. Any engine.
I've been thinking about the basic principles of IC engines and why they stall. I've got years of experience in tuning A -series Mini engines on Dynos but not V Twins
, but I understand the principles of IC engines and they are the same for 4 stroke cycles although today, engines are running literally on air to cope with very tight emission regulations - the result is a nightmare of electronic control and regulation - made even more complex by auxiliary throttles and baffles. The very slightest increase in fuel at idle makes a huge difference to low speed throttle response, that could be one of the reason remapping has helped for some riders. But if owners have to fit a power commander to resolve the issue clearly Suzuki has some remapping to do. My friend had a TDM900 Yammy parallel twin, which had a remapping recall something to do with engine braking and idle issues. The remap made all the difference apparently.
Back firing is usually associated with retarded ignition timing if through the exhaust, if back firing through the air box, then its more than likely caused by a weak mixture particularly on low RPM / or during the engine being under no load.
Just thinking about the basics here...
From my experience if an engine is running too lean it will stall and "knock" from pre - ignition (pinking). If its running rich, it will hunt an produce a regular heavy pulsing exhaust note. One of the techniques for setting up carbs is snapping open the throttle and quickly releasing it, if the engine revs drop quickly or the engine stalls when the rpm reaches idle speed, then the mixture is too lean and needs to richer. One solution is increase the idle speed to establish a better air intake velocity at low rpm
I'm just sharing my thoughts here blokes..(I don't work for Suzuki..) A couple of things to consider with the new 1000 engine, firstly it has a heavier flywheel than any other Suzy V, secondly, the emissions are soo low at idle , I'm suprised the thing idles at all. From my experience, if there was an air leak between the throttle and cylinder head, the engine wouldn't idle full stop on a fuel injected engine or it would stall regularly. On a carb engine, a slight air leak may cause a rise in rpm resulting in an uneven rpm.
I'm thinking along the lines of when the throttle is blipped on the 1000, because of the large displacement and heavier bottom end coupled with the fact that the engine is a twin it won't like "short" low speed blips, particular as the air intake speed and fuel atomisation needs a short time to get regulated. I remember blipping the throttle on my Wee when changing down the gears and sometimes it would back fire into the airbox and miss a beat. Only ocasionally and only when I "blipped". Now a 4 cylinder or even triple has more power strokes per revolution, resulting in a freer , linear air flow. The cylinder displacement also is smaller. Any V twin won't take kindly to low speed short term throttle changes, without been given time to increase rpm.
It will be interesting to find the cause of some of the issues Veek owners are having. I'm friends with a local motorcycle engine builder who also has a dyno and years of experience in re-mapping. I'll have a chat with him, I'm sure he will be keen to have a further look.
