Ryobi PLT3043A / PLT3043YW Questions & Answers

Unleaded 91 petrol. Small engine 2 stroke oil.

From what I can see comparing images of the two carbies, they are more or less identical. Correct me if I'm wrong; I believe the 'YE' variant differs from the 'A' variant only aesthetically (ie. external plastic cowling, appearance, attachments, etc). So yes, they should be perfectly interchangeable. Worst case scenario, the high and low speed jets would only need slight adjusting - an easy exercise.

No clutch in the PLT3043A. Direct drive full time.

Air gap setting of .008 to .012 (8 to 12 thousandths of an inch) is to be made with a shim between flywheel magnets and ignition pickups in 2 places simultaneously. The ignition module and flywheel must not touch each other for 360 degrees of flywheel operation. I use a cardboard business card to gap the coil to the flywheel and works fine. As long as there is no contact on a full rotation, you're good. Prior to my teardown, I noticed the gap was incredibly small. A business card worked fine upon rebuild.

This engine uses a Champion RCJ-6Y or an NGK BPMR7A with 0.63 mm electrode gap.

1. Stop the engine, disconnect the spark plug wire. Hold the bump head and unscrew the bump knob. Turn counter-clockwise. 2. Remove the spool from the bump head. NOTE: Keep the spring attached to the spool. Remove any old line remaining on the spool. 3. Cut two pieces of line, each being approximately 2.7 m (9 ft.) long. 4. Insert the first line into the anchor hole in the upper part of the spool. Wind the first line around the upper part of the spool counterclockwise, as shown by the arrows on the spool. Place line in the slot on upper spool flange, leaving about 152mm (6 in.) extended beyond the slot. Do not overfill. After winding the line, there should be at least 6mm (1/4 in.) between the wound line and the outside edge of the spool. 5. Repeat above step with second line, using the bottom part of spool. Do not overfill. 6. Replace the spool and the bump knob.

They are superceded.

Why would the pull cord not work

Engine displacement is 30 cc. Max engine performance is 0.78 kW (1.05 hp).

Pull cord problems could be related to the plastic cog in the pull starter housing, not engaging with the spring loaded tabs on the flywheel due to worn/rounded teeth. If the cord does not pull out at all, there could be too much compression in the cylinder due to carbon buildup on the piston head, or a seized piston due to corrosion buildup in the cylinder - try pulling again after removing the spark plug to remove pressure. My pull start problems were caused by a seized inner bearing in the crankcase, preventing the rotation of the crankshaft and everything connected to it. A big (but not impossible) job to replace. Runs like new now. But try the most likely (and easier) checks first though; ie. removing the whole drive shaft housing (4x torx screws, 2x electrical wire connectors 1x throttle cable mount torx screw & finally the throttle cable linkage from the carby), then remove the pull starter assembly off the motor (4x torx screws on the front and 2 on the rear from memory) and have a look inside to make sure the spring mechanism pulls and retracts correctly. Squirting some WD-40 Silicone Spray to lubricate the cog's rotation wouldn't hurt. Also check the condition of the plastic cog to make sure its teeth aren't too rounded and worn - I've seen dudes cut the teeth so they're sharp again. Next apply WD-40 lubricant to the flywheel spring-loaded tabs to make sure they move quite freely. Finally, see if you can rotate the flywheel by hand. You should feel quite a lot of compression, but still be able to rotate it a full 360 degrees. If this doesn't budge, you'll need to do more surgery to get into the crank case and cylinder to inspect the cause. All very repairable though.

For 20 years, I've only ever half filled the tank for each use - enough that the fuel pickup filter is submerged at all operating angles. The total fuel tank capacity is 425ml. Remember to empty the fuel tank after each use to prevent stale fuel gumming up in fuel lines and carburettor and blocking flow. These are the official numbers if they mean anything to you: 1. Fuel consumption (in accordance with ISO 8893) at max. engine performance - 0.52 kg/h. 2. Specific fuel consumption (in accordance with ISO 8893 at max. engine performance - 0.47 kg/h. So I'm guessing one full tank, at full throttle, will last almost 1 hour.

Hard to answer exactly. Suggest looking up a video on youtube. But basically, the motor crankshaft output is effectively hard-connected to the flywheel. There are no gears or clutch - purely a direct drive which subsequently rotates a flexible rod through the shaft housing, down to the trimmer head. The end of the rod is squared and passes through a fixed ball bearing into an arbor spindle, which carries the bumper head outer casing. The inner spool head is spring loaded and secured within, by the bumper knob at the very bottom. To extend the trimmer line while the engine is running, rev the motor slightly and firmly tap the bottom of the cutting head a couple of times on the ground. Each tap forces the spring loaded internal spool head upwards, centrifugal forces extend the cutting line outwards a couple of cm each tap. The excess line is severed by a small razor edge on the grass deflector assembly. The Ryobi Pro Cut II Head is available from Bunnings and is compatible with this trimmer, but I've tried it and still prefer the original style bumper-head - less stopping and starting the engine to extend the cutting line each time.

Yes, the flexible drive shaft needs to be fed as far as it can fit back into the flywheel. As long as the drive shaft is fully engaged down at the cutting head end, it should naturally mate up with the spindle in the flywheel when you reconnect the drive shaft housing back onto the engine.

I've found the original bumper head style is most effective for the PLT-3043A. I have tried the newer Pro Cut 2 head, and although it provides a cleaner vertical edging cut than the original bumper style, it is so so inconvenient stopping to replace the cutting line lengths every 10 mins. Also, once you lose over an inch off your cord length, performance is reduced, meaning you need to throw out the remaining lengths and insert fresh cord - such a waste. Also, fixed cutting blades are NOT recommended for these models (PLT-3043A and PLT-3043YW) - motor doesn't have enough grunt to sustain at speed and overcome extra load.

I no longer have this Susan, I can't remember if there was a filter or not.

Yes, a fuel filter at the end of the fuel line in the tank is necessary. Due to the operating environments of whipper snippers, you're going to get fine debris in the tank at some stage. Without a fuel line filter in circuit, the only thing preventing particles entering your combustion chamber is a super small and super fine little piece of gauze in the carburettor. This tiny little gauze is prone to gum up with poor fuel anyway - any extra debris will block the fuel entering the chamber.

The fuel supply hose (with filter on end) connects to the innermost pipe on the carby - the tube closest to the engine. The return line connects to the outermost carby tube - the tube closest to the air filter housing.

I've tried a few, but have had the best results with 2.0mm diameter line. Anything over that causes issues when using the bump head to extend the line - it binds up and gets stuck. Also, the thicker the line, the more it 'bashes' the grass, rather than 'slashes' it - if that makes sense? Makes your edges look terrible.

You've done everything I would have done. Only think I can think of as it heats up the bore expands and it loses compression hence the power drop off. Piston rings may need replacing and now we are getting into an expensive area. I have switched to battery operated due to the area I need to do now is a lot smaller. So far I have had an issue and have not had to deal with fuel mixtures etc.

Thanks Culprit. I have checked the ring gap and checked for ware. At this time, I am confused as to how to adjust the fuel adjustment screw. Even Ryobi claim that they don't have any adjustment information for these machines. ;(. Do you and / or anybody know how to reduce the fuel adjustment jet / screw when it is covered by a white plastic pointer cover. I'm supposed to turn it 1/16 - 1/8 clockwise, but I can't work out how to turn it ?

Try adjusting the High and Low mixture screws on the Carby . That model usually comes with a "ZAMA" carby being a C1U type . If that doesn't work then buy a Diagram and gasket kit for $15 for the carby as its common for the diagram to dry out out after time. on all 2 stroke machines. Make sure you pull off the carby first to get the model model number first which is written on the carby before buying a gasket and diagram kit as it not unusual for different types of carby model numbers were used . I am guessing yours will be a C1U-H28 or a C1U H48A . If your screws have covers just pop them off to adjust them . You usually need a PACman type screwdriver ( $10 on ebay) to adjust the old ZAMA carbs but you can use a hacksaw to cut a groove into them to use a regular screw driver. just watch YOUTUBE how to cut the screws out with a hacksaw

I don’t think so and the model is obsolete in Australia now

The safety section of the manual states "Use only original manufacturer's replacement parts, accessories and attachments. Failure to do so can cause possible injury, poor performance and may void your warranty". Additionally, attaching heavier metallic cutting attachments will place an extra load on your engine, causing it to struggle and increase wear.

1. Engine starts but will not accelerate: Carburettor requires adjustment: Turn "L" needle counterclockwise 1/16 turn. If "L" low needle can not be turned counterclockwise, do not force plastic limiter caps. Contact a servicing agent.

2. Engine starts but will only run at high speed at half choke: Carburettor requires adjustment: Turn "H" needle counterclockwise 1/16 turn. If "H" high needle can not be turned counterclockwise, do not force plastic limiter caps. Contact a service agent.

3. Engine does not reach full speed and emits excessive smoke: Carburettor requires adjustment: Turn "H" needle clockwise 1/16 - 1/8 turn.

4. Engine starts, runs, and accelerates but will not idle: Carburettor requires adjustment: Turn idle speed screw clockwise to increase idle speed.

5. Oil drips from muffler: Carburettor requires adjustment: Turn "H" needle clockwise 1/16 - 1/8 turn. Oil dripping from muffler also caused by running the engine at part throttle - increase to full throttle while operating.

Note: The "L" Low Speed Jet screw is the inner screw closest to the engine body, while the "H" High Speed Jet screw is the outer screw closest to the air filter housing assembly.

This link describes the process of tuning: external link 

It's hard to explain but here's a link external link 

being a 2-stroke engine you need to take unleaded petrol and mix it with a 2-stroke oil at a 50:1 fuel ratio, eg 5 Litre of fuel to 100ml of oil

Two stroke

Unleaded 91 octane petrol, mixed with 2 stroke oil, at a ratio of 50:1 (ie. 5L of petrol and 100ml of oil).