4 Cycle FULL CRANK Straight Shaft String Trimmer

Model: #RY4CSS

4.5 | 1972 Reviews
The 4 Cycle Straight Shaft String Trimmer brings power, less hassle, and performance to your lawn maintenance. The 4 cycle low emission engine and REEL-Easy bump feed string head make trimming your yard a breeze while keeping the air around you cleaner. The straight shaft allows for extended reach trimming under decks, around obstacles, and in hard to reach places. With the RYOBI 4 Cycle string trimmer, you no longer have to worry about mixing gas and oil. This innovative unit is attachment capable, accepting all nine of the Expand-It universal outdoor attachments. Backed by a RYOBI 3 year warranty while offering less hassle and mower power, the RYOBI 4 Cycle Straight Shaft Trimmer is the residential string trimmer of choice.


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  • Engine Type: 4 Cycle/Stroke Low Emission Engine
  • Trigger: Variable Speed Throttle
  • Cutting Path: 18 in cutting swath
  • String Diameter: .095 in. dual line
  • Line Advancement: Bump Feed
  • Attachment Coupler: universal attachment coupler
  • Weight: 11.8 lb.


  • S430 Straight Shaft String Trimmer
  • Ergonomic Front Handle
  • Straight Shaft Grass Guard/Deflector
  • ReelEasy™ String Head
  • 4 Stroke Engine Lubricant
  • Funnel
  • Operator’s Manual


4 Cycle FULL CRANK Straight Shaft String Trimmer
4 Cycle Attachment Capable String Trimmer is rated 4.5 out of 5 by 1972.
Rated 1 out of 5 by from The last piece of Ryobi products that I buy I bought the trimmer about a month ago. I used the 4 cycle trimmer three times. I had to put string on it. It opened easily and then couldn't put it back together. Something in the trimmer head seems broken and parts are no longer available. It should be under warranty. I paid $325.40 for it on July 22, 2023 and I want a refund.
Date published: 2023-11-17
Rated 5 out of 5 by from Great weedeater! Bought this a couple weeks ago, along with a Ryobi 2-in-1 Pivoting Bladed Head, in hopes of using it to clear some larger weeds/small shrubs along our driveway. It was very easy to put together, and the cutting head was incredibly easy to switch out. I added some oil and gas, 2 pulls and it was running! Chewed through the heavier weeds no problem, greatly simplifying my job!
Date published: 2023-11-06
Rated 5 out of 5 by from Best Good it’s easy to running and good quality. I will use it lot
Date published: 2023-10-24
Rated 4 out of 5 by from Powerful I bought this a few weeks ago and it is a good product, except it uses a lot more gas for a 4 cycle engine than I am used to. It takes 4 tanks of gas to be able to weed eat around everything on 1 acre property, the string guard is a little to small for it. The power is great and it will sling items into your legs and feet. It would also help if a shoulder harness was included.
Date published: 2023-10-07
Rated 3 out of 5 by from Did work good Got it 2 years ago and tore up this year can't find receipt for it so I have a broke 1
Date published: 2023-10-05
Rated 4 out of 5 by from Trimmer Con Fuerza. Es un equipo potente, pero la tuerca que aguanta el mango es plástica y en la primera usada tuve que remplazarla por una de metal ya que perdió la rosca. Además que el protector que tiene debería ser un poco mas grande ya que cuando está cortando la grama y las piedritas dan en las piernas por mas tapado que uno éste. Si ese protector fuese un poco mas grande eso no ocurriría. También hubieran agregado una correa para sostener el trimmer ya que para trabajos de larga duración se cansa los brazos sostenerlo asi sin nada, la correa hubiera sido de gran ayuda para esos trabajos de larga duración.
Date published: 2023-09-27
Rated 4 out of 5 by from Workhorse that does a great job! This is my second Ryobi gas straight trimmer. First one lasted nearly 7 years, so I had no problem deciding on what brand to buy this time. My only complaint with purchase was the bottle of oil was not sealed correctly at the factory. It was in the sealed bag with other included parts, but a little messy. Better QC at the factory would have caught this. Overall this is a workhorse that just like my first Ryobi years ago, ALWAYS starts with one pull.
Date published: 2023-09-24
Rated 5 out of 5 by from 4 cycle what more can ya say I purchased this and it has made my life a lot easier them weeds don't stand a chance.....
Date published: 2023-09-22
Rated 4 out of 5 by from Good trimmer Bought to replace the old one that lasted 6 years.
Date published: 2023-09-13
Rated 5 out of 5 by from Best weedeater ever I just purchased this about 2 days ago. Best weedeater I have ever used. The amount of power this thing has amazes me. I cut through everything brush and all. It is so good on fuel I cut my whole yard and still have a half of tank. No mix no Hassel. The bump head is amazing the whole thing is. Thanks ryobi tools!!! Y'all went the extra mile on this product.
Date published: 2023-09-09
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