Arrow Performance Mufflers - Motorcyclist magazine

Moto Guzzi V7 Classic Removing Material On Cylinders

Round and round she goes, until she stops. Precise amounts of material were removed from the top of the V7’s cylinders with the help of a lathe.

Round and round she goes, until she stops. Precise amounts of material were removed from t

Some nice stainless-steel Arrow performance mufflers came with the bike. They looked restrictive, though. A dyno run confirmed this, so I cut the baffles with my Sawzall until I could see daylight.

After a few more changes and further dyno runs, the V7 managed 44.60 bhp at 6500 rpm. Peak power before the mods was 37.98 hp, so my work was good for a 17 percent gain, including a 10-bhp bump at 7000 rpm. Broadband torque is more important for a streetbike, and usable powerband is up from near-idle to almost redline. The best part of this project is all the engine modifications are in the top end. No need to remove the engine or split the cases; it’s outpatient surgery!

There’s no need for aftermarket pistons or cylinders on this Italian hot rod. The Guzzi's simple Heron-style heads make modifying the stock parts very effective.

There’s no need for aftermarket pistons or cylinders on this Italian hot rod. The Guzzi's

The stock V7 only carries 2 quarts of oil, and this well-known design issue leaves little margin for error. I’ve seen these bikes burn a full quart during hard, high-speed break-in runs, which leads to rising oil temperatures and catastrophic bearing failures. Overfilling to maximize oil capacity leaves a big puddle underneath the engine as that extra oil sneaks out the breather. My fix? Make a 3-quart sump extender to provide cheap insurance.

After all this work, I’ve been riding the V7 around San Francisco for the past few months. It’s a great grocery-getter and errand-runner, and in the canyons is stable and stealthy. Those barely legal exhausts make the diminutive V-twin sound like a Gatling gun in the city; short-shifting calms the commotion to a low moan.

Moto Guzzi’s small-block V-twin usually plays the pesky kid brother to the company’s big-block motors, but the V7 series has potential. After our little outpatient procedure, this one makes almost enough power to keep up with its looks.

Up Close

Combustion central: The V7 Classic’s 80mm dished pistons constitute its combustion chambers. These were clearanced slightly so the valves wouldn’t hit.
Combustion central: The V7 Classic’s 80mm dished pistons constitute its combustion chamber
The time-honored solder method was used to accurately measure squish clearance between the piston and head. Setting this properly unlocks power.
The time-honored solder method was used to accurately measure squish clearance between the
Don't like cutting baffles? A set of nicely finished stainless-steel Arrow megaphone exhausts gave our Guzzi a bigger bark and more bite.
Don't like cutting baffles? A set of nicely finished stainless-steel Arrow megaphone exhau