Echo CS-310/CS-590 Problems | Gas Chainsaw Repair Guide

Echo’s CS-310 and CS-590 are reliable gas chainsaws popular with homeowners and professionals. Known for easy starting and durability, these saws handle years of service with minimal fuss. Echo has been building outdoor power equipment since 1972 and their chainsaws reflect decades of engineering refinement. When problems develop, this guide helps diagnose and fix common issues so you can get back to cutting.

Table of Contents

• Model Comparison
• Starting Problems
• Engine Issues
• Carburetor
• Chain and Bar
• Oiling System
• Maintenance
• Frequently Asked Questions

Model Comparison

Understanding the differences between these two saws helps with troubleshooting and parts selection.

Feature	CS-310	CS-590
Engine	30.5cc	59.8cc
Power	1.73 HP	3.89 HP
Bar	14-16”	18-24”
Weight	8.8 lbs	13.9 lbs
Fuel Capacity	8.5 oz	21.8 oz
Oil Capacity	6.8 oz	10.2 oz
Chain Speed	4,720 FPM	5,313 FPM

Echo CS-590 featuring the i-30 starting system for reliable cold starts

The CS-310 targets homeowners tackling occasional firewood, pruning and storm cleanup. Its lighter weight makes it easy to handle for extended periods. The CS-590 steps up significantly in power and is built for serious firewood processing, larger tree felling and demanding property maintenance. Professional landscapers often choose the CS-590 as a mid-range workhorse.

Both models feature Echo’s i-30 starting system that reduces pull force by 30% compared to conventional starters. This makes cold starting much easier, especially in cooler weather.

Starting Problems

Starting issues are the most common complaint with any chainsaw. Echo’s i-30 system helps, but problems still occur.

Won’t Start Cold

The Echo i-30 starting system has a specific procedure that works best when followed exactly.

Proper cold start procedure:

1. Set choke lever to full choke position
2. Move throttle to fast idle (throttle lock engaged)
3. Pull starter cord until engine fires (usually 3-5 pulls)
4. Move choke to half position
5. Pull again until engine runs
6. Move choke to run position and let idle warm up

If the saw won’t start cold, check these items:

1. Fuel condition - Must be fresh 50:1 mix (Echo recommends their Power Blend or similar quality 2-stroke oil). Fuel older than 30 days is suspect.
2. Spark plug condition - Remove and inspect. Should be tan/brown colored. Black and wet indicates flooding. White indicates lean condition.
3. Primer bulb - Press until you see fuel in the bulb. If fuel doesn’t appear, check fuel lines and filter.
4. Air filter - Must be clean for proper air/fuel mixture.

A properly functioning spark plug should have a tan to light brown electrode

Won’t Start Hot

Hot starting should be simple - no choke needed, just 2-3 pulls.

If the saw won’t hot start:

• Flooded condition - Too much fuel in the cylinder. Wait 10 minutes and try with throttle wide open.
• Vapor lock - Fuel vaporizing in hot carburetor. Loosen fuel cap to check for pressure, then retighten.
• Carburetor running lean - May need adjustment or cleaning.

Flooding Recovery

A flooded engine has too much raw fuel in the cylinder and can’t ignite.

Recovery procedure:

1. Remove spark plug
2. Pull starter cord 10-15 times with throttle wide open
3. Clean and dry the spark plug (or install fresh plug)
4. Reinstall plug
5. Try starting with choke OFF and throttle open
6. If still won’t start, let sit 20 minutes for fuel to evaporate

Prevention: Don’t over-prime and don’t pump throttle repeatedly during starting attempts.

Engine Issues

Beyond starting problems, these engine issues commonly affect Echo chainsaws.

Engine Surging

Surging (RPM fluctuating up and down) indicates a fuel delivery or air leak problem.

Common causes:

1. Carburetor adjustment needed - L screw affects idle and low-speed mixture
2. Air leak at intake - Check gaskets between carburetor and cylinder
3. Clogged fuel filter - Restricts fuel flow causing lean surges
4. Dirty air filter - Creates rich condition at idle, lean at full throttle
5. Cracked fuel lines - Allows air into fuel system

Diagnosis: If surging stops when you cover part of the air intake with your hand, suspect a lean condition (clogged fuel filter or carburetor needs richening).

Lacks Power

A saw that starts but cuts poorly frustrates users. Work through these causes systematically.

Power loss causes (most to least common):

1. Dull chain - The #1 cause of poor cutting. A sharp chain pulls itself through wood.
2. Dirty air filter - Restricts airflow, reducing power output
3. Clogged spark arrestor - The screen in the muffler plugs with carbon
4. Carburetor needs tuning - High-speed adjustment affects full-throttle power
5. Compression loss - Worn rings or scored cylinder (high-hour saws)
6. Exhaust port carbon buildup - Restricts exhaust flow

Regular air filter cleaning prevents power loss and engine damage

Overheating

Chainsaws run hot, but excessive heat damages engines.

Overheating causes:

1. Lean fuel mixture - Running lean generates excess heat. Adjust H screw slightly richer.
2. Blocked air filter - Engine can’t breathe properly
3. Dirty cooling fins - Sawdust packed around cylinder prevents heat dissipation
4. Damaged flywheel fan - Reduced cooling airflow
5. Using wrong fuel mix - Too little oil causes excess friction heat

Signs of overheating: Engine dies under load, hard hot starting, scoring on piston/cylinder.

Carburetor

Echo chainsaws use quality Walbro or Zama carburetors that rarely fail outright but need periodic adjustment and cleaning.

Echo Carburetor Basics

Adjustment screws:

• L (Low) - Controls idle and low-speed fuel mixture
• H (High) - Controls full-throttle fuel mixture
• T (or LA) - Sets idle speed

Most Echo carburetors have limiter caps on L and H screws restricting adjustment range for EPA compliance. These caps can be removed for full adjustment range, though this may affect warranty coverage.

Basic Carburetor Adjustment

Proper adjustment requires a tachometer for best results, but field adjustments are possible.

Adjustment procedure:

1. Start saw and let warm up 2-3 minutes
2. Set T screw for reliable idle (chain should not move at idle)
3. Turn L screw clockwise until engine stumbles, then back out 1/4 turn
4. Rev to full throttle and adjust H for maximum RPM, then richen 1/8 turn
5. Verify clean acceleration from idle to full throttle
6. Readjust T if needed

Warning: Running too lean (H screw too tight) causes engine damage. Always err on the rich side if unsure.

Carburetor Service

When adjustment alone doesn’t solve problems, the carburetor needs service.

Signs carburetor needs rebuild:

• Won’t adjust properly within normal range
• Leaking fuel from carburetor body
• Diaphragms stiff or damaged
• Internal passages clogged despite cleaning

Rebuild kit cost: $12-20 and includes all gaskets, diaphragms and needle valve.

When to replace: If carburetor body is cracked, threads stripped, or multiple rebuilds haven’t solved problems. Replacement carburetors run $25-45.

Chain and Bar

The cutting system needs regular attention for best performance.

Chain Tension

Proper chain tension is critical for safe cutting and chain life.

Correct tension procedure:

1. Loosen bar nuts (don’t remove)
2. Lift bar nose up
3. Turn tensioner screw clockwise until chain snugs against bar bottom
4. Hold bar nose up while tightening bar nuts
5. Check: chain should pull freely around bar and snap back when lifted 1/4” from bar

Proper chain tension allows slight lift from the bar while staying in the groove

Check tension frequently - new chains stretch significantly during break-in. Recheck every few cuts initially.

Chain Won’t Cut

A sharp chain makes cutting easy. A dull chain makes work miserable.

Signs of dull chain:

• Produces fine sawdust instead of chips
• Must push saw hard to cut
• Saw pulls to one side
• Smoke while cutting
• Chattering or bouncing in cut

Sharpening options:

• File by hand (proper size round file for chain pitch)
• Electric bench grinder
• Professional sharpening service ($5-10)

Replace chain when: Teeth worn past witness marks, damaged by rocks or dirt, or severely stretched.

Bar Maintenance

Bars wear out too and need periodic attention.

Bar maintenance tasks:

• Clean bar groove of sawdust and debris
• File burrs from bar rails
• Flip bar periodically for even wear
• Check bar nose sprocket spins freely (if equipped)

Oiling System

The automatic oiler keeps the chain lubricated. Problems here cause rapid chain and bar wear.

No Bar Oil

Systematic diagnosis:

1. Check tank - Is there oil in the reservoir?
2. Test pump - Remove bar and chain, run saw briefly. Oil should spray from outlet.
3. Clean oil outlet - Sawdust can plug the oil passage
4. Check bar groove - Clean groove allows oil to reach chain
5. Inspect oil filter - Located in oil tank, may be clogged

Adjusting Oil Output

Both CS-310 and CS-590 have adjustable oil pumps.

Adjustment: Small screw near oil outlet. Turn clockwise to decrease output, counterclockwise to increase.

Settings: Increase oil for dusty conditions, larger bars, or hardwood. Decrease for light work or smaller bars to conserve oil.

Maintenance

Preventive maintenance keeps Echo chainsaws running for years.

Every Use

• Check chain tension before starting
• Check bar oil level
• Inspect chain for damage
• Clean air filter (dusty conditions)

Every Tank of Fuel

• Clean air filter
• Check bar condition and flip if needed
• Inspect chain for dull or damaged teeth
• Clear sawdust from cooling fins

Every 10 Hours

• Clean spark arrestor screen
• Inspect spark plug (replace if fouled)
• Clean all cooling fins thoroughly
• Check fuel filter in tank
• Lubricate bar nose sprocket (if equipped)

Annually or 50 Hours

• Replace fuel filter
• Replace air filter
• Install new spark plug
• Inspect all fuel lines (replace if cracked)
• Check starter rope condition
• Service carburetor if needed

Common Parts

Part	Echo Part #	Cost
Air filter	A226001410	$12-18
Spark plug	15901019830	$5-8
Fuel filter	13120507320	$6-10
Chain (CS-310)	91PX52CQ	$15-20
Chain (CS-590)	72LPX70CQ	$20-28
Bar oil	6459012	$8-12/qt
Carburetor kit	12310008560	$12-20

Frequently Asked Questions

CS-310 vs CS-590 - which should I buy?

CS-310 for occasional homeowner use - pruning, small firewood, storm cleanup. CS-590 for serious firewood processing, larger property maintenance, or light professional use. The CS-590 costs more but handles bigger jobs much faster.

Are Echo chainsaws reliable?

Very. Echo consistently ranks among the most reliable chainsaw brands. The i-30 starting system works well, engines are durable and parts are readily available. Many professionals use Echo as their backup or mid-range saw.

How does Echo compare to Stihl and Husqvarna?

Comparable quality at often lower prices. Echo’s i-30 starting system arguably beats competitors for easy starts. Stihl has the biggest dealer network. Husqvarna offers more professional models. All three brands make quality equipment.

What fuel mix does Echo recommend?

50:1 ratio using Echo Power Blend X or equivalent high-quality 2-stroke oil. Use 89 octane or higher fuel. Never use E15 or higher ethanol blends - E10 maximum.

Why does my Echo chainsaw die at full throttle?

Usually a fuel delivery issue. Check fuel filter, fuel lines for cracks, and carburetor high-speed adjustment. Could also be clogged spark arrestor restricting exhaust.

How often should I sharpen the chain?

Whenever cutting slows noticeably or you see sawdust instead of chips. For typical use, sharpen after every 2-3 tanks of fuel. Touch up more frequently if hitting dirt or cutting dirty wood.

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• Small Engine Fuel Problems

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Echo chainsaws are reliable workhorses built for years of dependable service. Keep fuel fresh, chains sharp and air filters clean. Follow the maintenance schedule and these saws will reward you with easy starts and strong cutting performance season after season.