Weber Marelli ECU problems

This site has been superceded by the new My16M site

Third party dependence

Its a black box that I know nothing about. If it fails I have no way of knowing what has gone wrong or how to fix it. This is contrary to the usual intimacy that a Guzzi owner has with their machine.
You may not be surprised to hear that it has just failed me. It failed in the middle of nowhere and it kept the bike off the road for over 4 weeks. It cost me over $1000 to get it fixed although this did include a new battery. The original battery suddenly failing allowed a voltage surge to damage the ECU.

System performance

Although it works fairly well it falls it bit short of my expectations. While cruising at suburban speeds it has an occasional and inexplicable miss as if it just forget to fire the spark on that cycle. Also while idling happily, it will sometimes simply wind down, requiring a save with the throttle. The bike has a tendency to ping. I'm lucky if I can get much more than half throttle under some conditions and that is using the best available fuels and even octane boosters. Some of these problems may not have anything to do with the ECU but with the current lack of information on the unit who can tell.


The only way to configure the ECU is with a EPROM change. While not overly expensive it is very much hit and miss as to whether it performs better or worse then the EPROM it replaces. I'm pretty sure the missing is inherant in the software design of the ECU so I reckon any aftermarket EEPROM will not eliminate it entirely.