New Regal Raptor DD250-2N in Shanghai

[macieq]

Hey Nuhaus,

Yes we have compared with Dan's RR (also EFI) and there is no second cable. I also saw and older RR with carbs at the said store on Sunday and that one had 2 cables. I explicitly poinetd it to the mechanics and understood from his geistures that it is intentional.

[euphonius]

For what it's worth, our 600cc Jialings with EFI also have single throttle cables, not a dual push-pull system. I can only speculate as to why EFI systems might be more tolerant of the single cable system. Though I've never opened the throttle valve (节气阀 jieqifa), the exploded diagram shows that the throttle cable does nothing more than throw open a butterfly valve, thus allowing air into the chamber for mixing with injected fuel. The mixture then is sucked into the cylinder when the intake valve opens and the piston recedes, creating vacuum. This is basically the same as what happens in a carburetor, though a carb has more mechanical things going on inside with a float chamber and floats, etc. So perhaps there are more places that can get gummed up, thus creating friction that could cause the butterfly valve to close less responsively under spring force.

As of now, I get very good engine braking just by downshifting and then rolling off the throttle. Not sure the second cable would make a huge difference, but it might.

Anyone have any ideas why EFI might be less demanding of a second cable to positively pull the throttle valve shut? MJH?

cheers

[Ario]

Dear all,

my name is ario, form Indonesia, i am also use Regal Raptor NAC 25, i would like to modified my carburetor, did anyone know what is applicable carb for RR NAC 25, thanks

A