Troubleshooting a String Trimmer that has Lost Power
A few simple maintenance practices can help restore the performance of a faulty string trimmer (Weed Eater).
Check the Age of the Fuel
Today’s ethanol-containing gasoline can break down in relatively short time periods. If your blended fuel supply is more than two or three weeks old, blend a new batch of fuel. AMSOIL Saber Pro now features an additional fuel stabilizer to help offset these effects.
Check Air Filter Condition
A clogged air filter prevents the engine from receiving sufficient air to operate properly. Before removing the air filter, brush away loose debris from around the filter cover and filter element. Tap the filter on a tabletop or the palm of your hand to dislodge any dirt or debris. If you use compressed air, make sure you direct air through the filter from the inside to avoid lodging debris deeper in the filter. Avoid washing the filter as this can collapse its micro-fine structure. If cleaning doesn’t remove debris, replace the filter with the appropriate part recommended by the trimmer manufacturer.
Check the Spark Plug
Spark plug fouling occurs when oil, carbon or other foreign substances coat the tip of the plug and interfere with normal firing. Too much oil in the gasoline, inferior oil, a dirty air filter and/or continued operation at less than full throttle will eventually cause spark plug fouling. Replace the spark plug with a new one recommended by the trimmer manufacturer.
If a new plug is not immediately available, remove the plug and clean all carbon and oil deposits from the plug tip. Set the gap according to the manufacturer’s recommendations and reinstall the plug.
Clean the Exhaust Spark Arrestor Screen
On many trimmers, a small screen covers the exhaust outlet and prevents sparks from exiting the muffler and potentially starting a wildfire. For this reason, trimmers should not be operated if the screen is missing, punctured or disintegrating.
As with plug fouling, too much oil in the gasoline, inferior oil, a dirty air filter and/or continued operation at less than full throttle will plug the screen with carbon deposits. This prevents exhaust gas flow, which leads to power loss. To fix the problem, remove the spark arrestor screen and inspect it for plugging. If plugged, either replace it with the appropriate part recommended by the trimmer manufacturer or clean it.
To clean the spark arrestor screen, spray it with AMSOIL Power Foam® to soften the deposits before cleaning the screen with an abrasive pad. Reinstall the screen and test the weed wacker.
If these attempts to restore power fail, take the trimmer to your servicing dealer.
Use High-Quality Oil to Help Avoid Power Loss
Using a high-quality two-stroke oil with excellent detergency can help avoid many of the problems listed here. Two-stroke oils that burn cleanly help reduce plug fouling and spark arrestor screen deposits. AMSOIL SABER® Professional Synthetic 2-Stroke Oil withstands high heat and stress to protect handheld equipment engines against wear and harmful deposits. It can be mixed at conventional mix ratios (32:1, 40:1, 50:1) or the SABER Ratio™ (80:1, 100:1), offering the convenience of one mix ratio for all applications.
Just by using the AMSOIL 2-cycle oils you will have the last laugh when you first bring out your trimmers and yard tools and they start right away. Still after making the suggestion to your other Sioux Falls neighbors they will insist their method is better and struggle with starting and a un-necessary cloud of smoke. That’s right folks, AMSOIL’s Saber is practically smokeless and we get praise on its lack of foul order just as we do with our other 2-stroke oils for powerports.
Take care of your yard equipment and trust AMSOIL for your lubricants and also checkout our award winning fuel treatment designed for small engines – AMSOIL Quickshot – cleans, prevents fuel issues, stabilizes (non 2-cycle too) fuel and prevents the effects of ethanol.
Find all AMSOIL Saber PRO 2-cycle products and bottle sizes in our local Sioux Falls store
Synthetic Warehouse
4610 W. 12th St
Sioux Falls, SD 57107
402-933-3902
*All trademarked images are the property of their respective owners and may be registered marks in some countries. No affiliation or endorsement claim, express or implied, is made by their use. All products advertised here are AMSOIL-engineered for use in the applications shown.
Following 300 hours of professional-use testing in Stihl* string trimmers at the manufacturer mix ratio of 50:1, SABER Professional kept pistons and rings virtually free of carbon and wear (see the picture on the left), while use of a leading oil brand caused significant carbon buildup around the ring area (see the picture on the right). This engine is nearing the failure point.
After 300 hours of simulated severe use while running SABER Professional, the exhaust-port on the left exhibited virtually no signs of blocking. In contrast, after 300 hours of simulated severe use while running a leading oil brand, the exhaust port on the right exhibited severe exhaust-port blocking. This engine barely idled at the end of the 300-hour test.
Exhaust gases flow through the spark arrestor screen (located directly on the muffler), which is prone to plugging. Using SABER Professional, the screen on the left did not require cleaning following 300 hours of severe-service testing. In contrast, using a leading oil brand, the screen on the right plugged after only 45 hours of runtime and required repeated cleaning throughout the test.
Outstanding Protection for Zero-Turns and Other Four-Stroke Equipment
Keeping piston ring and land areas clean is critical to maintaining the power and performance of zero-turn mowers. Following 500 hours of severe-service testing in the Kawasaki* FX 730 V engine, Formula 4-Stroke Synthetic Small Engine Oil kept pistons and rings virtually free of carbon and wear.