6 Jonsered Chainsaw Pressure Testers For Engine Repairs
Keep your equipment running smoothly with our top 6 Jonsered chainsaw pressure testers for engine repairs. Compare the best professional tools and buy yours today.
Nothing slows down a busy harvest season quite like a Jonsered chainsaw that refuses to start or loses power under a heavy load. Maintaining a two-stroke engine requires catching air leaks early, long before a scored piston turns a minor repair into a total engine failure. Investing in a quality pressure tester is the most effective way to ensure your equipment stays ready for the next pile of firewood or orchard maintenance task.
Disclosure: As an Amazon Associate, this site earns from qualifying purchases. Thank you!
Mityvac MV8500: The Pro-Level Vacuum/Pressure Kit
The Mityvac MV8500 is the gold standard for those who demand precision and versatility across an entire fleet of small engines. It functions as both a vacuum pump and a pressure pump, allowing for thorough testing of impulse lines, fuel systems, and crankcase seals.
Because of its robust construction and accurate gauge, this kit is an ideal choice for the serious hobby farmer who maintains multiple saws, trimmers, and leaf blowers. The high-quality materials ensure that the seals inside the tool won’t perish after a few seasons in a dusty shop.
While it represents a higher initial investment, the long-term reliability justifies the cost. If the goal is professional-grade diagnostic capability that survives decades of occasional use, this kit is the correct choice.
Stens 705-001: A Trusted Aftermarket Standard
Stens has long been a staple in the small engine repair world, and the 705-001 tester is a workhorse designed specifically for the mechanics who need a straightforward tool. It provides a reliable way to check for those pesky crankcase leaks that cause lean running conditions.
This unit is perfect for the individual who wants an “out-of-the-box” solution without unnecessary bells and whistles. It fits most common Jonsered carburetor inlets and spark plug ports with minimal fuss, saving precious time when the saws need to be back in the field immediately.
While it may lack the extensive accessory list of more expensive kits, its simplicity is its greatest strength. For a straightforward, reliable tool that does one job extremely well, the Stens 705-001 is a solid recommendation.
8milelake Tester: Best Value for Occasional Use
Budget constraints are a reality for every hobby farmer, and the 8milelake tester proves that effective diagnostics don’t have to break the bank. This kit comes with an extensive array of adapters that accommodate a wide variety of small engine configurations.
This tester is recommended for the occasional user who only repairs a saw once or twice a year. It provides the necessary data to determine if a seal is compromised, even if the build quality isn’t intended for daily professional shop use.
It is a smart purchase for those who prefer to have a wide range of adapters on hand for various off-brand equipment. For the occasional mechanic who values utility over high-end aesthetics, this kit offers the most bang for the buck.
Walbro 57-11: The OEM-Quality Pressure Tester
When dealing with sensitive two-stroke carburetors, there is no substitute for the precision of an OEM-style tool. The Walbro 57-11 is specifically engineered to test the integrity of needle valves and gaskets, which are the most common failure points in Jonsered fuel systems.
Choosing this tool is an investment in accuracy. Because Walbro manufactures many of the carburetors found on Jonsered saws, their testing equipment is calibrated perfectly for the specific pressure requirements of these engines.
It is highly recommended for those who have exhausted other troubleshooting methods and need to verify the performance of a carburetor rebuild. If precision matters more than the variety of included adapters, skip the generic kits and opt for the Walbro.
A ABIGAIL Engine Tester: Most Complete Adapter Set
The A ABIGAIL Engine Tester stands out primarily for its sheer volume of adapters, making it the most versatile option for a mixed-brand workshop. If there are various types of power equipment lying around the barn, this kit likely has a fitting for all of them.
This kit is designed for the problem solver who enjoys tinkering with vintage equipment or non-standard engine builds. The adapters are clearly labeled, which simplifies the testing process when working on unfamiliar Jonsered models.
While the sheer number of parts can be overwhelming at first, the convenience of having every possible fitting at arm’s reach is invaluable. This is a must-have for the hobbyist who finds themselves working on a wide range of different small engine platforms.
Motion Pro 08-0188: Simple, Reliable Gauge
Motion Pro is a name synonymous with quality motorcycle and small engine tools, and their 08-0188 gauge is a testament to minimalist design. This is a dedicated tool for those who prefer quality over quantity and want a gauge that stays accurate for years.
The construction is rugged, and the gauge face is easy to read, even in low-light barn conditions. It is perfect for the farmer who already has a DIY vacuum source or a compressor and just needs a rock-solid, accurate measurement tool.
Do not be fooled by its lack of adapters; the accuracy and build quality are superior to many cheap, all-inclusive kits. This is the clear choice for the mechanic who prioritizes tool longevity and precision above all else.
Choosing a Tester: Complete Kit vs. Single Gauge
Deciding between a complete kit and a standalone gauge depends entirely on existing shop infrastructure. A complete kit is essential for someone starting from scratch, as it provides the necessary fittings to connect to various spark plug holes and impulse lines.
However, if the shop is already equipped with basic fittings or a vacuum pump, a standalone gauge is often the better value. High-quality gauges hold their calibration longer, whereas cheap, massive kits often suffer from leaks within the included hoses and quick-disconnect fittings.
- Complete Kits: Best for those with no existing diagnostic tools and a variety of different engine types.
- Standalone Gauges: Recommended for those seeking higher accuracy, professional longevity, and who likely already possess basic plumbing/adapter components.
Step-by-Step: Pressure Testing Your Engine
To begin, ensure the engine is clean, especially around the spark plug port and the intake manifold. Remove the spark plug and install the tester’s adapter firmly, ensuring the seal is airtight.
Pump the tool to the manufacturer’s specified pressure, usually between 7 and 10 PSI. Observe the gauge carefully; if the needle drops steadily, there is a leak in the system.
If the pressure holds for at least 30 seconds, the seals are likely intact. If it drops, use a soapy water solution to spray around the crank seals and intake boot to look for bubbles, which will pinpoint the exact location of the leak.
Understanding Pressure and Vacuum Test Results
A successful pressure test indicates that the engine’s “lungs” are sealed, preventing air from entering where it shouldn’t. If the pressure drops, it signals that the engine will run lean, causing it to overheat and potentially seize during heavy cutting.
Vacuum testing is equally critical for checking the health of the crankshaft seals. A crank seal that holds pressure but fails under vacuum will allow air to be sucked into the crankcase, leading to erratic idling and poor acceleration.
Always perform both tests when troubleshooting a persistent running issue. A comprehensive check covers the fuel delivery system, the crankcase, and the cylinder base, providing a complete picture of engine health.
Finding Leaks: Seals, Gaskets, and Carb Boots
The most common culprit for pressure loss in a Jonsered saw is the intake manifold boot, which often cracks from age and fuel exposure. A secondary offender is the crankshaft seal, which typically leaks behind the flywheel or the clutch assembly.
If the pressure continues to drop after ruling out the boot, check the cylinder base gasket for signs of seepage or oil buildup. Even a minute failure in these components will ruin the air-to-fuel ratio, rendering the most finely tuned carburetor ineffective.
Don’t ignore small leaks in the hope that they will “seal up” once the engine warms up. Persistent leaks lead to piston damage that cannot be reversed. Replacing a $5 gasket now is a fraction of the cost of a full engine rebuild later.
Investing in a pressure tester is not an indulgence; it is a fundamental part of responsible, long-term equipment management. By taking the time to master these diagnostics, any hobby farmer can prevent the frustration of engine failure and ensure their saws are always ready to work. Stay proactive, keep the seals tight, and the equipment will serve the farm well for many years to come.
