It can be done but you must use an electronic filter if you do so.
The only one of those that I use nowadays is the Tech Aero unit. there are a couple of others around but I have not had much success with them.


[link]http://www.tech-aero.net/ultra-ibec[/link]

What Voltage does your ignition require? If it requires more than 6 volts the Tech Aero unit is the only one I have found that will supply it reliably to the ignition.
If it is a simple "4 cell pack" requirement, then the weight saving is pretty negligible.

Even 2.4 can suffer from intereference. Don't ever rely on it to shroud a poor build or installation or product.