Boosting the Performance of Husqvarna's Legendary 372XP Chainsaw

Improving the Performance of the Husqvarna 372XP Chainsaw

The Husqvarna 372XP is a professional-grade chainsaw that is popular among loggers, arborists, and homeowners with lots of property to maintain. This 70cc saw is designed for excellent power-to-weight performance and is known for its reliability and smooth operation. However, there are several modifications that can be made to improve the 372XP's cutting speed, torque, and fuel efficiency even further.

Aftermarket Cylinders

One of the best ways to get more power out of the 372XP is to install an aftermarket cylinder kit. These kits come with a new cylinder, piston, rings, gaskets, and sometimes a decompression valve. Popular options are from Meteor, Pro maxResults, and Solo. An aftermarket cylinder increases displacement to around 80cc resulting in more torque and higher chain speeds.

Porting

Having the cylinder exhaust and intake ports professionally widened, smoothed, and polished can significantly increase airflow and engine performance. This process, known as porting, is best left to experienced chainsaw mechanics. In combination with a bigger cylinder, porting can boost power by 30% or more. The saw will run cleaner at high RPMs leading to less engine wear over time.

Muffler Mods

Modifying the stock muffler by drilling holes or removing the spark arrestor screen reduces backpressure which allows the engine to expel exhaust gases faster. This simple upgrade adds noticeable power throughout the RPM range. It also enhances throttle response and makes the saw run cooler. Just be sure to check local laws as muffler mods can increase noise.

Adjusting the Carburetor

Having the carburetor professionally tuned can optimize the air/fuel ratio for maximum power gains. Turning the high-speed jet clockwise leans out the mixture for increased revs while counterclockwise enriches it for a little more torque. Adjusting the low speed screws also helps with acceleration and idle. Just don't over-lean the fuel mixture which can cause damage over time.

Filing the Muffler Baffle

Carefully filing down the interior baffle in the muffler produces similar benefits as drilling holes. This smooths airflow and reduces engine-robbing backpressure. Best results come from removing the baffle altogether. But this drastically increases noise so consider adding a spark arrestor screen to keep things legal.

Advancing Ignition Timing

Advancing the ignition timing delivers a hotter spark optimized for maximum combustion pressure. This also reduces ignition delay. While somewhat complicated, advancing the flywheel a few degrees typically yields 300-400 extra RPMs. This helps the modified 372XP reach peak horsepower.

Installing a Decompression Valve

A decompression valve temporarily bleeds compression for much easier starting. This upgrade is most beneficial after boosting displacement and compression via an aftermarket cylinder kit. Easing pull force saves wear and tear on your arm and the chainsaw's starter mechanism.

Running Higher Octane Fuel

To prevent premature ignition, always run the recommended 50:1 gas-to-oil ratio but consider switching to high-octane, premium fuel. This allows further advancing ignition timing and experimenting with leaner carb settings without detonation issues. The extra cost is worth the extractor power.

Getting an Adjustable Carburetor

Swapping the stock carb for an aftermarket adjustable unit provides precise fuel tuning. This allows dialing in the ideal air/fuel ratio for maximum power and throttle response. Adjustable carbs also permit further modification down the road. Popular options are from Walbro and Tillotson.

Upgrading the Air Filter

A clogged air filter restricts airflow into the carburetor reducing power. Upgrade to a premium filter that flows more cfm while trapping smaller dirt particles. This supports better combustion and keeps the engine running cooler while preventing early wear.

Installing Dual-Port Muffler

For the biggest power gains, upgrade to a dual-port muffler designed to significantly boost exhaust flow. This type of muffler comes standard on the highest performance Stihl and Husqvarna models. Match one to your particular 372XP for peak RPMs and torque across the power band.

Adding a Wrap Handle

Installing an aftermarket wrap handle gives you a second grip position for enhanced control and less fatigue while bucking logs. It also reduces the risk of your hand slipping onto the hot muffler. Pick a compact design that doesn't interfere with the chainsaw's balance and maneuverability.

Safety Considerations When Modifying Saws

It's crucial to exercise caution when modifying your 372XP to prevent damage, bodily harm, and violating noise ordinances. Here are some important safety tips to know:

• Allow only experienced mechanics to perform modifications
• Follow all recommended porting guidelines
• Check local noise regulations
• Limit muffler mods to responsible levels
• Don't over-lean carburetor fuel mixtures
• Make sure ignition timing isn't too radical
• Wear hearing protection when testing changes
• Keep an adjusted saw tuned properly

With the right upgrades and careful tuning, the already impressive Husqvarna 372XP can transform into a championship-level cutter. Just be sure to prioritize safety through every step of the modification process.

FAQs

What are the benefits of porting a Husqvarna 372XP?

Porting the cylinder smoothing and polishing the exhaust and intake ports increases airflow and engine performance. This professional upgrade can boost power by 30% or more when combined with a bigger cylinder kit.

Does advancing the ignition timing require special tools?

Yes, advancing the flywheel timing requires some specialized tools like a degree wheel and piston stop. It also requires in-depth knowledge of chainsaw engines. Best to have this done by an experienced mechanic.

What safety gear should be worn when testing performance upgrades?

Always wear chaps, steel-toe boots, thick gloves, eye and ear protection. Have a first aid kit on hand. Work in a clear area away from bystanders. Pay close attention to safety procedures.

Can muffler modifications violate local noise laws?

Yes, removing too much of the muffler baffle and spark arrestor can make the chainsaw illegally loud. Limit mods to reasonable levels and check local ordinances to avoid fines.