ive heard of people using 4 carbs from a bike......anyone ever done this on a rotary??????

 

Yes. Sometimes done in racing applications for engines that run only at high RPMs and have aggressive porting. Note that is a very narrow field of application.

 

i have a 12a bridgeport in a 70 mg midget with 456 posi that i race in s.c.c.a,my problem is the eldabroke 500 cfm 4 barel cuts out in hard corners and cant afford $900 for sidedraft and intaks.been trying to fing a good deal on used...but thoes that will sell want prem price.im a mechinest of 13yrs and was auto mech for 17...so i can build the intake,an have acess to bike carbs.my have to give it a try...only be out my time if it doesent work!

 

That sounds like the application. Another option is a set of bike ITBs and an inexpensive EFI controller like the Megasquirt.