V-Star 1100 High
Compression Pistons: Performance Without Compromise
An internal combustion engine operates on a simple but powerful
cycle: fresh air enters the cylinder, mixes with fuel, gets
compressed, ignited, and expelled as exhaust—then the process
repeats. The tighter this air-fuel mixture is compressed, the more
potent and efficient the combustion becomes.
The stock pistons in the V-Star 1100 deliver a compression ratio
of 8.3:1, classifying it as a low-compression engine. This setup is
optimized for low-octane fuel and mass production, offering ease of
tuning and broad reliability—but it limits performance potential.
Upgrading to our 10.6:1 high-compression pistons transforms the
V-Star 1100 into a true performance machine. After extensive testing
across a range of compression ratios, we’ve found 10.6:1 to be the
sweet spot—delivering enhanced power while maintaining engine
durability and long-term reliability.
You might wonder: if 10.6:1 is good, why not go higher—say 11:1
or 12:1? The answer lies in a critical issue: pre-detonation, or
"pinging." As compression increases, the air-fuel mixture becomes
more volatile and generates more heat, raising the risk of
spontaneous ignition before the spark plug fires.
In a properly timed engine, the spark plug ignites the mixture
just before the piston reaches Top Dead Center (TDC), ensuring
maximum power as the piston begins its downward stroke. But with
excessive compression, the mixture can ignite prematurely due to
heat and pressure alone—causing pre-detonation.
This premature ignition sends shockwaves through the cylinder,
disrupting the combustion cycle and placing extreme stress on
internal components. It can lead to power loss, mechanical
instability, and damage to pistons, rings, rods, pins, and even the
crankshaft. Worse still, even silent pre-detonation can push
cylinder temperatures so high that aluminum-alloy pistons may fail
or melt—resulting in catastrophic engine damage.
Consider this: at 4,000 RPM, each piston fires 33 times per
second. That’s a lot of opportunity for things to go wrong if
compression isn’t carefully managed. Some competitors may claim that
higher compression always means more power—but that’s a risky
oversimplification.
Our 10.6:1 pistons strike the perfect balance between performance
and protection. If you have further questions or want to explore how
this upgrade can elevate your ride, we’re here to help!
V-Star 1100
High-Lift Cams: Power You Can Install Yourself
The V-Star 1100 is equipped with a Single Overhead Cam (SOHC)
engine, which simplifies camshaft upgrades compared to more complex
internal modifications. No need to remove the engine or use
specialized tools—if you're comfortable adjusting valve clearances,
you can install new cams yourself.
This engine uses two camshafts—one per cylinder—each featuring
two lobes. These lobes actuate the rocker arms, which in turn
control the intake and exhaust valves through the four strokes of
the combustion cycle:
Intake: The intake valve opens as the
piston descends, drawing in the air-fuel mixture.
Compression: Both valves close as the
piston rises, compressing the mixture.
Power: The valves remain closed while
combustion drives the piston downward.
Exhaust: The exhaust valve opens as the
piston ascends, expelling spent gases.
Increasing valve lift allows more air into the cylinder,
enhancing the air-fuel charge and boosting power. High-lift cams are
engineered to achieve this—but too much lift can lead to problems
like piston-to-valve contact or valve float at high RPMs. Valve
float occurs when springs can't close the valves quickly enough,
compromising performance and reliability.
Stock valve springs on the V-Star 1100 can safely accommodate
cams with up to 0.450" lift. Our Triple X2 cams,
with a 0.438" lift, are precisely tuned for this setup. For riders
seeking even greater performance, our Triple Z cam
delivers nearly 0.500" lift and requires dual valve springs to
manage the added stress. The Triple Z also reduces valve overlap,
improving low-end torque—but installing it does require engine
removal to upgrade the springs.
All our cams feature nickel-based hardweld lobes—the industry’s
most durable solution for long-term reliability. This process
involves returning your stock cam core, which we then rework to our
exact specifications. Unlike billet heat-treated cams that may wear
out in under 5,000 miles, our hardweld cams routinely exceed 100,000
miles in real-world use.
While seasonal delays may occur due to core returns, we believe
this is a worthwhile tradeoff for unmatched durability and
performance. If you have any questions or want help choosing the
right cam for your build, we’re here to assist!
V-Star 1100 Flat
Slide Carburetors: Instant Response, Maximum Performance
Keihin is globally recognized as a leader in carburetor
technology, and their Flat Slide designs are among the most
responsive in the industry. Trusted by top-tier race bike
manufacturers, Keihin carburetors deliver exceptional
performance—and we’ve gone the extra mile to tailor them
specifically for the V-Star 1100.
From the factory, the V-Star 1100 comes equipped with Constant
Velocity (CV) carburetors. In this setup, the throttle grip doesn’t
directly control the slide; instead, the slide is lifted by engine
vacuum. While this design simplifies tuning for mass production, it
introduces a delay in throttle response. Even with a full twist of
the throttle, the slide won’t rise until sufficient vacuum is
generated—resulting in sluggish acceleration and a noticeable lag
before the engine delivers its full potential.
Our Keihin 39mm FCR Flat Slide carburetors eliminate that delay.
With a direct mechanical connection between the throttle cable and
the slide, throttle input translates instantly into engine
response—whether you're rolling on gently or going wide open. Plus,
the 39mm bore (up from the stock 37mm) increases airflow by 120
square millimeters, allowing more air and fuel into the engine when
needed.
The result? A significantly stronger powerband in the lower and
mid-range RPMs—right where most riders spend their time. While peak
horsepower gains are around 7 HP over stock, the real magic happens
in everyday riding conditions, where throttle response and torque
are dramatically improved.
Fuel efficiency also sees a boost during steady cruising and
touring—though aggressive riders may notice otherwise! When combined
with our other performance upgrades, these carbs deliver a
thrilling, responsive ride that transforms your V-Star 1100.
Keihin FCR carbs also offer exceptional tuning flexibility. With
a wide selection of needles and jets available, you can fine-tune
your setup to match your riding style and performance goals with
precision.
V STAR 1100 DYNA
3000 IGNITION
In 2004, Yamaha made changes to the ignition setup of the V-Star 1100 on certain models, primarily in California. However, some models with this change appeared sporadically in other regions as well. By 2005, the new ignition setup was implemented across all remaining states. This update involved a switch from a two-plug to a one-plug setup, though the box's basic functionality remained virtually unchanged.
To determine which Dyna 3000 ignition is compatible with your V-Star 1100, follow these steps:
Remove the driver’s seat to access the ignition module located directly beneath it.
Check the stock module:
If it has two separate sets of wires connecting to the module (two plugs), you’ll need the Dyna 3000.
If it has one wire plug set, you’ll require the Dyna 3000 Single Plug (V2).
Cylinder Replating:
Restoring Precision and Performance
Modern motorcycle engines benefit greatly from Nickel
Ceramic plating, a high-precision process that dramatically
improves heat dissipation and maintains tighter bore tolerances by
reducing thermal expansion and contraction. This advanced surface
treatment is far superior to traditional steel sleeves, offering
exceptional hardness and durability. In fact, it’s not uncommon for
plated cylinders to retain their original hone cross-hatching even
after 70,000 miles of use.
Historically, cylinder repairs or over-bores required inserting a
steel sleeve and machining it to spec. While effective in the short
term, this method introduces a thermal barrier between the piston
and the engine’s cooling fins, leading to increased operating
temperatures. Over time, this can degrade performance and shorten
engine life.
Our cylinder replating service restores the full
benefits of Nickel Ceramic technology, ensuring your engine runs
with maximum precision, efficiency, and longevity.
