It's a dirt bike, not a snowmobile.
Just for the record, ALL the 4T guys were crying their eye out, waiting for EFI to "save" the 4T's and their carburation problems. Madscientist warned said fools about all that would happen, including catalytic converters on the bikes, with the soon to follow emmissions testing!!
Yes, 4T fan, this is part of what you get, more hassles.
Now, go to page 88 in the December issue of Dirt Bike.
I'll quote it out for you.
THE ISSUE: You have a new FI CRF450R Honda, and in spite of the new mapping to the throttle body, the machine still coughs and tends to flame out at low rpm.
THE PRODUCT:Injectioneering specializes in performance EFI development. Injectioneering re-engineered the 2009-10 CRF450R throttle body to improve the throttle response (zero to quarter throttle region) and eliminate stumbling and stalling characteristics of the stock throttle body.
Emphasis obviously mine.
Courtesy Dirt Bike magazine, December 2009, page 88, top of page.
All EFI did was make things more complicated. I can get the stumble out of any 4T with a carb. You just wouldn't like the cost, or the peripheral problems you get when you take the stumble.
Again, be careful what you swallow from these (ANY) manufacturer.
I have spent 20 plus years screwing with FI off all types. 99% of the time, a carb is better, makes more HP and more torque.
That being said, some things require FI. Such as blown fuel (or nitomethane in any application) blown alcohol, blown gas. EFI is great for your daily driver and tow rig. Other than that.....................