Model # 990R Official Ryobi string trimmer

Here are the diagrams and repair parts for Official Ryobi 990R string trimmer, as well as links to manuals and error code tables, if available.

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Model diagram and schematic

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Showing 10 of 155 parts |

#15

Cylinder head diagram

Cylinder

Part #181039

The manufacturer no longer makes this part, and there's no substitute part

#23

Clutch,starter module&fuel tank diagram

Fuel line

Part #181086

The manufacturer no longer makes this part, and there's no substitute part

#NI

All parts diagram

Flywheel key

Part #610676

The manufacturer no longer makes this part, and there's no substitute part

Screw

Part #181003

The manufacturer no longer makes this part, and there's no substitute part

#23

Lower boom & cutting head diagram

Spring

Part #610636

The manufacturer no longer makes this part, and there's no substitute part

#12

Lower boom & cutting head diagram

Blade assembly

Part #682061

The manufacturer no longer makes this part, and there's no substitute part

#23

Carburetor and muffler diagram

Baffle

Part #181062

The manufacturer no longer makes this part, and there's no substitute part

#NI

All parts diagram

Line

Part #180120

The manufacturer no longer makes this part, and there's no substitute part

Lead wire

Part #181094

The manufacturer no longer makes this part, and there's no substitute part

Clutch,starter module&fuel tank diagram

Isolator

Part #181072

The manufacturer no longer makes this part, and there's no substitute part

Symptoms for gas line trimmers

Choose a symptom to see related grass line trimmer repairs.

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Why won't my gas line trimmer start?

Main causes: stale fuel, cracked fuel lines, dirty carburetor, bad spark plug, worn piston rings…

Why does my gas line trimmer run rough?

Main causes: stale fuel, clogged fuel filter, faulty spark plug, clogged air filter, cracked fuel lines, clogged carbure…

Why does my gas line trimmer leak gas?

Main causes: cracked fuel lines, bad carburetor seals, leaky fuel tank cap, damaged fuel tank…

Repair guides for gas line trimmers

These step-by-step repair guides will help you safely fix what’s broken on your grass line trimmer.

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How to rebuild a line trimmer carburetor

If the line trimmer engine won't start even though there's fuel in the tank, the carburetor could be the problem. Follow…

Repair difficulty

Time required

15 minutes or less

How to replace a line trimmer carburetor

If the line trimmer won't start even though there's fuel in the tank, the carburetor could be the problem. Follow these …

Repair difficulty

Time required

15 minutes or less

How to replace a line trimmer fuel line

The fuel line on a grass line trimmer deteriorates with time and eventually can split or crack. You can replace it yours…

Repair difficulty

Time required

15 minutes or less

Articles and videos for gas line trimmers

Use the advice and tips in these articles and videos to get the most out of your grass line trimmer.

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Top 10 electric lawn and garden tools for 2023

Model # 990R Official Ryobi string trimmer

Model diagram and schematic

SEARCH WITHIN THIS MODEL

Symptoms for gas line trimmers

Why won't my gas line trimmer start?

Why does my gas line trimmer run rough?

Why does my gas line trimmer leak gas?

Repair guides for gas line trimmers

How to rebuild a line trimmer carburetor

How to replace a line trimmer carburetor

How to replace a line trimmer fuel line

Articles and videos for gas line trimmers

Top 10 electric lawn and garden tools for 2023

How to enjoy all the online benefits we offer on our Sears PartsDirect website

Grass line trimmer maintenance checklist

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