MV F4 750 - Modern classic receives Brain Surgery

Every now and then, a bike rolls into the workshop that makes everyone stop and take a second look, the kind of machine you don’t see all that often these days. For those old enough, we are reminded of how cool they were back in the day and it provides an opportunity for the younger folk to learn a little about sports bike progression over the years.

When the MV Agusta F4 750 rolled of the production line in 1999, the model was an instant thing of beauty with the exotic price tag to match. The power output for a 750cc sports bike at the time was seriously impressive. The model had a life span from 1999 to 2004 before it was replaced by the 1000cc variant.

This 2003 beauty came into the workshop after the customer did a track day and found the bike just wasn't running right.

The rider’s feedback was simple:

“It just doesn’t feel right — underpowered and not running well.”

The Diagnosis

Straight away, our team noticed it was only running on two cylinders. To make matters stranger, someone had bumped up the idle just to keep it alive. That’s a bit like turning up the volume to fix a broken speaker — it doesn’t solve the real problem.

We rolled the bike through our standard diagnostic process . What we found was interesting — the fault wasn’t mechanical at all, but hiding inside the ECU. After performing multiple diagnostic tests using an oscilloscope, it was determined that the ECU had internal faults which warranted further investigation

Enter Our Electronics Guru

Cesar AKA Richie

As this specific ECU is no longer available as a replacement part for this model, we proceeded with opening the unit to determine if an internal repair was possible.

This is where our in-house electronics specialist, Cesar (or Richie, as the crew calls him), shines. Instead of boxing the ECU up and sending it off, Cesar carefully opened it up right here in the workshop.

Two MOSFETs related to the injector control were replaced, and a damaged resistor in one of the injector tracks was also repaired. After reassembling the ECU, further oscilloscope testing confirmed that the ECU and all four injectors are now functioning correctly. The ECU was then sealed, reinstalled, and the motorcycle was started. All four cylinders are now firing as expected, indicating successful repair of the ECU.

Running on all 4

With the ECU repaired and reinstalled, we fired the MV back up. Instantly, it came to life on all four cylinders. The real test came on the dyno, where it pulled strong numbers — seriously impressive power for a 750 of this era. It’s a reminder of just how well these MV engines were built, and why they still deserve respect today.

Why It Matters

For us, it’s more than just fixing what’s broken. It’s about giving these exotic machines the attention to detail they deserve, and keeping them running the way their makers intended. In this case, that meant not just finding the problem, but repairing it in-house with the right expertise.

Big thanks to Cesar for the precision electronics work — and to our customer for trusting us with such a special machine. a top job, really well done!!

On the Race Center dyno to make sure it is now running right and on all 4 cylinders.

Very decent power for a bike that's almost 25 years old with the OEM exhaust. This would mean around 135hp range at the engine