Currently, I own a 2000 Road king with the dreaded Magnetti Marelli EFI. What I have decided to do was a full blown custom job as a winter project. So in starting this project, I've decided to purchase an S&S T124 Long block engine without a fuel or ignition system. Since the T124 will fit 1999 -'06 big twins, I bought the Screamin' Eagle Pro 58mm Throttle Body with High Flow Intake Manifold so now my question is this while I wait for the engine to be built. Do I need to change my ECM? And if I do, will I also need a different wiring harness to fit the throttle body?

Any advice would be appreciated.

Later, in a different thread, I'll be asking transmission questions. This is my first rodeo.

 

There's nothing dreaded about MM, except misguided internet folklore. Darned good reason for a serious upgrade though! Why didn't you simply buy your engine with the whole nine yards? Then it would all go together and work properly. S&S has a replacement system for your stock MM, called S&S Variable Fuel Injection or VFI, which has better tunability than the stock set-up.

 

+1 on that. S&S makes a 58 MM throttle body and a ECM that's compatible with the wiring and fuel tank on your bike. Would be less work then using the SE throttle body.

 

I guess I kind of jumped the gun when I bought the SE throttle body, but, I purposely didn't buy the fuel or ignition system so I could learn while I build. By trade I'm a computer network geek but started working on my bike this year (and have a few other threads out there on it) and really started to enjoy the frustrations. LOL

 

I had looked into using a newer Delphi system on my 2000, and couldn't find that much information on converting one to work.
You should look at the S&S website and check the tech section. The instruction sheets/manuals can be downloaded.
I did a S&S ECM, 52mm, and O2 sensors on mine.

 

I would use the S&S system. Converting to a Delphi is some serious business. You will like the S&S system.

 

So DanDMan and wurk..... are yousaying I will have to get the EFI main wiring harness for *cough* $770 then the efi? and if so which did you use? (this is where I'm hitting a wall) Did you go with the VFI closed loop fuel injection kit? And what about ignition?

 

I pieced mine together for about $1300, basically a 52mm Throttle Body Kit with 02 sensors. It uses the stock harness and the S&S ECM. Plug & play. The ECM allows you to download your own maps using Pro Tune 2. If you go with 02 sensors you add 3 wires to the ECM plug.
There's one on ebay, it's a complete 52mm kit. Maybe they can get you a 58mm kit.

http://www.ebay.com/itm/141008419312?

Here's a 58 mm kit (not a complete one)

http://www.ebay.com/itm/S-S-58mm-THR...01-TWIN-CAM-W-