Echo CS-310 and CS-590 Troubleshooting: Starting, Power and Oiling

Chainsaws
T
Tom Bradley
ASE Certified Small Engine Technician, 25+ Years Experience

Echo chainsaws require fresh 50:1 fuel mix (2.6 oz oil per gallon of 89+ octane gas). The CS-310 is a 30.5cc homeowner saw; the CS-590 is a 59.8cc pro model. Common problems include hard starting (old fuel—drain and refill), engine dies at full throttle (clogged fuel filter or spark arrestor) and chain not oiling (clean oil port, check oil pump). Carburetor adjustment screws: L=low speed, H=high speed, T=idle. Turn L clockwise until stumble, back out 1/4 turn.

These are the complaints I hear most about the CS-310 and CS-590—and they’re almost always fixable.

Echo makes solid chainsaws. The CS-310 is a great homeowner saw for pruning and occasional firewood. The CS-590 is a serious workhorse that handles bigger jobs. Both have Echo’s i-30 starting system that cuts pull force by 30%. When they’re running right, they’re reliable. When they’re not, it’s usually old fuel or a carburetor issue.

Comparing Echo CS-310 and CS-590 Models

SpecCS-310CS-590
Engine30.5cc59.8cc
Power1.73 HP3.89 HP
Bar length14-16”18-24”
Weight8.8 lbs13.9 lbs
Best forPruning, small firewoodSerious firewood, felling

The CS-310 is light and easy to handle all day. The CS-590 has nearly double the power for bigger cuts. Most homeowners do fine with the CS-310. If you’re processing cords of firewood, get the CS-590.

Cold Start Issues

Echo’s i-30 starting system works well—if you follow the procedure. Here’s the right way:

  1. Full choke, throttle locked in fast idle position
  2. Pull until engine fires (usually 3-5 pulls)
  3. Move choke to half position
  4. Pull until engine runs
  5. Move choke to run, let it warm up

If It Still Won’t Start

Check fuel first. Must be fresh 50:1 mix under 30 days old. Old gas is the #1 cause of chainsaw problems. Dump it, add fresh mix, try again.

Check the spark plug. Pull it out and look:

  • Tan/brown = good
  • Black and wet = flooded
  • White/gray = running lean

Check the primer. Press until you see fuel in the bulb. No fuel? The fuel filter or lines are clogged.

Check the air filter. A clogged filter prevents starting. Clean or replace it.

Hot Start Problems

Hot starting should be easy—no choke, just 2-3 pulls. If it won’t hot start:

Flooded: You over-choked or over-primed. Wait 10 minutes, then try with choke OFF and throttle wide open.

Vapor lock: Fuel vaporizing in the hot carburetor. Loosen the fuel cap to release pressure, retighten, try again.

Running lean: Carburetor needs adjustment or cleaning.

Flooded Engine Fix

Too much fuel in the cylinder. The plug is wet and smells like gas.

  1. Remove spark plug
  2. Pull starter 10-15 times with throttle wide open (clears excess fuel)
  3. Clean and dry the plug, or install a fresh one
  4. Reinstall plug
  5. Try starting with choke OFF and throttle open

Still won’t start? Let it sit 20 minutes for fuel to evaporate, then try again.

Prevention: Don’t over-prime. Don’t pump the throttle while trying to start.

Engine Surging

The RPM goes up and down rhythmically. The saw won’t hold a steady speed.

Most likely causes:

Quick test: Cover part of the air intake with your hand while it’s running. If surging stops, the engine is running lean—check the fuel filter and carburetor.

Power Loss Problems

The saw runs but won’t cut worth a damn. Work through this list:

  1. Dull chain — This is the #1 cause. A sharp chain pulls itself through wood. A dull chain just rubs.
  2. Dirty air filter — Restricts airflow, kills power
  3. Clogged spark arrestor — The screen in the muffler plugs with carbon over time. Remove and clean it.
  4. Carburetor H screw — High-speed mixture affects full-throttle power
  5. Compression loss — Worn rings or scored cylinder (high-hour saws only)

Overheating Solutions

Chainsaws run hot, but excessive heat damages engines.

What causes it:

  • Running lean (H screw too tight)
  • Blocked air filter
  • Sawdust packed in the cooling fins
  • Wrong fuel mix (not enough oil)

Warning signs: Engine dies under load, hard hot starting, metal-on-metal sounds.

Prevention: Clean cooling fins regularly. Run slightly rich rather than lean. Use correct 50:1 mix.

Carburetor Adjustment

Echo uses Walbro or Zama carburetors. They’re reliable but need occasional tuning. See our carburetor cleaning guide for the full process.

The Three Screws

  • L (Low) — Idle and low-speed mixture
  • H (High) — Full-throttle mixture
  • T (or LA) — Idle speed

Most Echo carbs have limiter caps on L and H that restrict adjustment range (EPA requirement). You can remove them for full access, but it may void your warranty.

How to Adjust

  1. Start the saw and let it warm up for 2-3 minutes
  2. Set T so it idles reliably (chain should NOT move at idle)
  3. Turn L clockwise until engine stumbles, then back out 1/4 turn
  4. Rev to full throttle, adjust H for max RPM, then richen 1/8 turn
  5. Check that it accelerates cleanly from idle to full throttle
  6. Readjust T if needed

Important: Running lean destroys engines. If you’re unsure, err on the rich side. A little smoke is better than a seized piston.

When to Rebuild or Replace

Signs the carb needs work:

  • Won’t adjust properly
  • Leaking fuel
  • Stiff or cracked diaphragms
  • Clogged passages that won’t clean out

A rebuild kit runs $12-20 and includes gaskets, diaphragms and the needle valve. Replacement carburetors cost $25-45. If you’ve rebuilt it twice and it still has problems, just replace it.

Maintaining Proper Chain Tension

Loose chains jump off bars. Tight chains wear fast and stress the engine. Get it right.

How to adjust:

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

New chains stretch a lot during break-in. Check tension every few cuts for the first tank of fuel.

Signs of a Dull Chain

A sharp chain pulls itself through wood. A dull chain makes you push.

Signs it’s dull:

  • Fine sawdust instead of chips
  • Have to push hard to cut
  • Saw pulls to one side
  • Smoke while cutting
  • Chattering or bouncing

Sharpen it:

  • File by hand (use correct file size for your chain pitch)
  • Electric bench grinder
  • Professional sharpening ($5-10)

Replace when: Teeth worn past witness marks, hit rocks or dirt, or severely stretched.

Bar Maintenance Tips

Bars wear out too. Every few uses:

  • Clean the groove of packed sawdust
  • File burrs off the rails
  • Flip the bar for even wear
  • Check that the nose sprocket spins freely

Oiler Issues

The automatic oiler keeps chain and bar lubricated. No oil = rapid wear.

No Oil Coming Out

  1. Is there oil in the tank?
  2. Remove bar and chain, run saw briefly—oil should spray from the outlet
  3. Clean the oil outlet (sawdust plugs it)
  4. Check the bar groove is clean
  5. Inspect the oil filter in the tank

Adjusting Oil Flow

Both the CS-310 and CS-590 have adjustable oil pumps. Small screw near the oil outlet.

  • Clockwise = less oil
  • Counterclockwise = more oil

Increase for hardwood, dusty conditions, or longer bars. Decrease for light work.

Maintenance Schedule

Every Use

  • Check chain tension
  • Check bar oil level
  • Quick chain inspection

Every Tank of Fuel

  • Clean air filter
  • Flip bar if needed
  • Clear sawdust from cooling fins

Every 10 Hours

  • Clean spark arrestor screen
  • Check spark plug
  • Check fuel filter
  • Lube bar nose sprocket

Every 50 Hours or Annually

  • Replace fuel filter
  • Replace air filter
  • New spark plug
  • Inspect fuel lines (replace if cracked)
  • Service carburetor if needed

Common Parts

PartEcho Part #Price
Air filterA226001410$12-18
Spark plug15901019830$5-8
Fuel filter13120507320$6-10
Chain (CS-310)91PX52CQ$15-20
Chain (CS-590)72LPX70CQ$20-28
Carburetor kit12310008560$12-20

Summary

Echo chainsaws are reliable. The CS-310 and CS-590 both have solid reputations for easy starting and long service life. When problems happen, it’s almost always old fuel or a dirty carburetor.

Keep the fuel fresh (under 30 days old), the chain sharp and the air filter clean. Follow the maintenance schedule. These saws will run for years.

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