I've heard there were "problems" with the Magneti-Marelli ECM that Harley used early on. Could anyone here offer more specific information about what these problems were?

I have a bike with this ECM and it kind of pops and sputters in the low RPM's. I'm wondering if this is a problem with the ECM itself or with the map.

TIA

 

From what I've learned, problems arise with the MMI system when the bike is modified. Mine (98RKC) has that system and aside from a bad head temperature sensor and poorly adjusted hot/cold idle setting has given me no trouble. Mine is also stock with the exception of a stage I kit.

You'll have to post up more information about your bike for someone to try and diagnose the problem.

 

This bike is one of the new Indian's. It's a 2010 Darkhorse Chief. Great bike, rides great, attracts a crowd.

I've been told that the way the MMI is mapped is the problem with the sputtering. That at low rpms the mixture becomes so lean (16/17:1) that the engine starves and that's causing the sputter. This is made worse because I live at 7000+ elevation and typically ride up into the 12000 range. So thin air + super lean AF ratios = sputtering.

I asked because I wanted to make sure the issue was the map rather than the MMI itself before I committed to a fix.

Thanks!

 

I have an older bike with the MM system, modded a fair bit. So far 70K without issues, Dyno'd and mapped by FuelMoto. Since it's an open loop system, it is not as flexible as later systems IIRC.