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Help Revive a Lawn Mower (and other equipment) that Runs Rough

Written by Charleen

Help Revive a Lawn Mower (and other equipment) that Runs Rough

John Baker|

Judging someone’s character can be boiled down to this key question: do they love going to the dump?

An affirmative answer indicates a visionary – one who sees a fashionably distressed dining set where others see a worn out table and chairs. One who sees the south wall of their new chicken coop where others see dusty old windows. One who sees his new (free) rolling shop stool where others see a ratty office chair.

Why drop $50 on a shop stool when you can get a sweet unit like this free at the dump?

So, while I salivate at adding a lawnmower, snowblower or other piece of equipment from the dump to my family fleet, I also burn with shame toward my fellow man for discarding something that might have been easily repaired.

There has to be a better way

One of the biggest reasons people junk their lawnmower, string trimmer, chainsaw or other equipment is because it starts hard and runs rough. A dirty carburetor is often to blame.

Over time, oxygen deteriorates the gasoline in the carb, leading to the formation of varnish and other deposits that stick the float, block the screens and plug the tiny fuel passages. The result? Fuel that doesn’t flow properly and an arm nearly ripped from its socket from fruitlessly yanking the starter cord.

Engine deposits are another problem

The combustion chamber grows intensely hot during operation. The heat breaks down motor oil, creating carbon that can lodge in the ring lands and cause the piston rings to stick. Stuck rings reduce engine compression, which makes starting more difficult and reduces engine power.

Gasoline byproducts can form deposits on the piston crown, which can lead to pre-ignition. That’s when a super-heated chunk of carbon ignites the fuel/air mixture before the spark plug fires, causing a shock wave in the cylinder that can lead to piston damage.

In two-stroke engines, deposits can block the exhaust port or spark arrestor screen, choking off airflow and leading to rough-running. If bad enough, the engine will quit running altogether.

String trimmer exhaust port plugged with carbon deposits, causing it to run poorly.

An effective way to prevent hard-starting, rough-running equipment is to treat gas with gasoline stabilizer prior to storage and to periodically clean the carburetor and combustion chamber with a good fuel additive. Otherwise, you’ll find yourself at the dump paying to dispose of your lawnmower, snowblower or other equipment while people like me lie in wait, rubbing our hands together with glee.

If your engine and carburetor are already dirty and causing grief, clean them with AMSOIL Power Foam. It’s a potent cleaning agent that…

  • Cleans deposits from ethanol and degraded fuel
  • Removes gum and varnish
  • Maximizes horsepower
  • Restores startability
  • Helps improve fuel economy
  • Reduces pollution

It will not damage seals, gaskets, rubber or plastic materials commonly used in gasoline engines.

I’ve tried it a few times on my lawn and garden equipment, and it’s pretty simple to use. Just run the engine to normal operating temperature, remove the air filter and spray Power Foam into the intake as fast as possible without stalling the engine. You may have to rev the engine to facilitate the process. Make sure you’re in a well-ventilated area because an impressive volume of smoke will emit from the exhaust.

Then, shut off the engine and let it sit for 10-15 minutes.

While you’re waiting, Power Foam‘s potent formula attacks and loosens the built-up carbon and varnish, helping free stuck rings, clean the valves and piston crown, and remove varnish from the carburetor. If the engine is especially dirty, you may want to repeat the process.

Replace the air filter, start the engine and pat yourself on the back for helping prevent the addition of one more perfectly usable piece of equipment to the local dump.

It may be unfortunate for scavengers like me, but it’s great for your wallet.

And here’s another Sioux Falls secrete for you lawn care customers!! A frequent weedeater problem easy to repair.

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Maintenance, , , , , , , ,

ECHO String Trimmer Technical Study

Written by Ches Cain

AMSOIL SABER® Professional Synthetic 2-Stroke Oil resisted performance-robbing deposits and maintained power and performance in ECHO string trimmers.

Published September 2016

Overview Government mandates require modern handheld trimmers and other twostroke equipment to produce less exhaust emissions. To comply, some original equipment manufacturers (OEMs) design their equipment to run on leaner fuel/oil mixtures. Burning more air and less fuel/oil, however, also increases heat. To withstand this intense environment and ensure equipment lasts as designed, modern two-stroke oils must demonstrate improved wear protection and detergency. Objective Demonstrate through lab testing that the latest generation** of AMSOIL SABER® Professional Synthetic 2-Stroke Oil exceeds the increased performance needs of ECHO* string trimmers in particular, and modern two-stroke string trimmers in general. Methodology Testing was conducted on eight ECHO trimmers in the AMSOIL mechanical lab and followed a test plan designed to compare two-stroke oils in simulated real-world conditions. Test duration is designed to simulate an extended length of service. The OEM’s recommended 50:1 mix ratio was followed.

test_parameters

SABER Professional was installed in four trimmers and ECHO Power Blend was installed in another four. Computer-controlled actuators operated the trimmer throttle triggers according to an identical protocol for each unit. Images of trimmers arranged on the test stand are included for reference.

trimmer_engine_set

 

Test administrators monitored engine rpm, spark-plug temperature, exhaust emissions and other parameters to ensure consistent, repeatable operation and gauge overall performance of each trimmer. After 300 hours of operation, the trimmers were disassembled and inspected. Note: Test results published in this Technical Study describe and represent properties of oils that were acquired on the dates listed in Table 1 on the facing page. Results do not apply to any subsequent reformulations of such oils or to new oils introduced after completion of testing. All oils were available to consumers at the time of purchase. Testing was completed in July 2016. The differences in effects between AMSOIL SABER Professional and ECHO* Power Blend* are statistically valid at the 95% confidence interval for exhaust port blockage and spark arrestor screen plugging.  The carbon buildup on pistons was not numerically quantified as part of the study.

Weed trimmer ready for engine testing

The test was run using two engines for each treatment. The study was then replicated using the same n=2 design. Exhaust- port blockage and spark-arrestor screen plugging were compared using a paired t-test. Equipment was run at factory-set conditions and there was no effort to intervene on any problems developed by the equipment outside of recommended maintenance in the owner’s manual. String trimmers arranged

Piston Rings/Piston Skirts

Deposits in the ring grooves can cause the rings to stick and lose effectiveness. Engine rpm can decrease and the engine cab lose compression. Significant compression loss leads to engine failure. Heavy deposits on the piston skirt increase friction and reduce performance.

Piston ring deposits with ECHO and AMSOIL

Deposits appear heavier on the pistons lubricated with ECHO Power Blend. The pistons lubricated with SABER Professional appear cleaner. SABER Professional provided improved detergency and extreme-heat resistance. Both oils guarded against piston ring sticking well.

Piston Crowns/Undercrowns Heavy piston crown deposits can cause preignition and poor performance. While undercrown deposits are unlikely to impede performance, they are an indicator of the oil’s detergency properties. With modern two-stroke equipment running hotter, oils must demonstrate strong detergency and heat resistance to maintain piston cleanliness and peak performance.

piston crowns undercrowns deposits from Echo oil

Pistons lubricated with ECHO Power Blend appear to contain heavier crown and undercrown deposits. In contrast, the piston crowns lubricated with SABER Professional look clean, with low levels of deposits. SABER Professional provided improved detergency and extreme-heat resistance.

Wrist Pins & Bearings The wrist pin and bearing are exposed to extreme heat due to their proximity to the combustion event. Ineffective lubrication can result in deposits, polishing and flat spots on the wrist pin restricting rotation. As the engine works to overcome this restriction, the piston can bear increased pressure, leading to scuffing and eventually failure.

wrist pins

All eight wrist pin bearings demonstrated no issues throughout the test, indicating the oils provided good protection. None of the wrist pins contain flat spots. Both of the oils performed well in this area.

Exhaust Ports

For the engine to run properly and produce maximum power, exhaust gasses must flow freely out the exhaust port during operation. Restricted exhaust causes RPM and power loss, starting difficulties and eventually, failure to operate.

Exhaust ports

SABER Professional demonstrated low exhaust-port deposits. In contrast, all four exhaust ports on the engines using the ECHO product suffered blockage, with two more than half blocked with deposits.

Note: Airflow loss was calculated using a flow bench to measure restriction which was converted to a percentage of flow compared to an unblocked exhaust post.

Spark Arrestor Screens

Exhaust gasses continually flow through the spark arrestor screen located on the muffler which is prone to plugging. Like the exhaust ports excessive deposits on the spark arrestor screen restrict airflow and reduced power.

Spark arrestor screens

SABER Professional demonstrated low spark-arrestor screen deposits. In contrast, screens on the trimmers lubricated with the ECHO product contained higher levels of deposits. The screen from engine 5 was nearly completely blocked with deposits after 239 hours of the 300-hour test and required replacement. On average screens from engines using ECHO Power Blend suffering 4X more airflow loss than screens on engines using SABER Professional 2-cycle oil.

Note: Airflow loss was calculated using a flow bench to measure restriction which was converted to a percentage of flow compared to an unblocked spark arrestor screen.

Main Bearings

The main bearings receive little lubrication given their location in the lower end of the engine. Deposits are an indicator of poor oil detergency. Heavy deposits can restrict bearing rotation and eventually lead to failure.

Echo main bearings

The bearings lubricated with SABER Professional appear to contain fewer deposits.

Crankcases

Oils with ineffective detergency properties can allow deposits to accumulate in the crankcase. During operation, deposits can circulate throughout the engine and reduce performance.

crankcase housing Echo

Crankcase deposits look heavier in the engines using ECHO Power Blend. The engines using SABER Professional appear clean and free of harmful deposits.

RPM & Spark-Plug Temperature

Reduced rpm and spark-plug temperatures are indicators the engine is producing sub-optimal power. This can be caused by heavy exhaust port and spark arrestor screen deposits which restrict air flow through the engine and result in reduced power. The following graphs depict the average rpm and spark-plug temperature of engines at wide-open throttle using SABER Professional and ECHO Power Blend.

Engines using SABER Professional maintained consistent power throughout the study, while the average spark-plug temperature declined slightly. In contrast, the engines using ECHO Power Blend slowly lost power as the study progressed. Similarly, the average spark-plug temperature suffered a drop.

RPM curve Echo string trimmer

Conclusion

As demonstrated in lab testing designed to simulate a full season of real-world use, AMSOIL SABER Professional Synthetic 2-Stroke Oil provides excellent protection for ECHO* brand string trimmers. SABER Professional outperformed ECHO Power Blend* XTended Life* Universal 2-Stroke Oil by providing improved resistance to piston deposits, crankcase deposits and exhaust port blocking. Due to its ability to limit exhaust-port and spark-arrestor-screen deposits, SABER Professional protected against rpm loss 21 percent better, resulting in reliable operation. The latest generation of SABER Professional meets or exceeds the increased performance requirements of ECHO SRM 225 trimmers.

AMSOIL fully supports the use of SABER Professional as a replacement for ECHO Power Blend XTended Life Universal 2-Stroke Oil, and warrants its use according to the AMSOIL Limited Liability Warranty (G1363).

Engine Tests, Sioux Falls Motor Oil and Lube News, , , , , , , ,