Echo Engine Torque Specs

Echo is the one handheld 2-stroke brand on this site whose documents are all first-party: every figure below was read from a PDF hosted on echo-usa.com or from Yamabiko's own service manual, rather than a dealer re-host. The SRM-2620ES service manual carries a complete "Torque… Read the rest ›

Limits" table — the most thorough published table of any handheld engine here — and it prints every value three ways, in kgf-cm, N·m and in-lbf, which makes each row self-checking. Note that Echo specifies most of these as bands, and that its M10 spark plug takes far less than the M14 plug on a Stihl or Husqvarna saw.

Where these numbers come from. 18 published figures, 1 confirmed gap, every source named. How we checked ›

The SRM-2620ES "1-3 Torque Limits" table is the primary source and also covers the Shindaiwa T262XS/C262S/T262TXS/C262TS. The CS-400, CS-590 and SRM-225 figures come from Echo operator's manuals on echo-usa.com, where they are printed as formal spec callouts rather than running text. Values are shown in the unit Echo itself printed — in-lb where Echo prints lbf-in, ft-lb where the figure is high enough for a ft-lb wrench to read it — with Echo's N·m figure recorded on every row. Echo also publishes a general fastener table for unlisted hardware (M3 0.6-1, M4 1.5-2.5, M5 2.5-4.5, M6 4.5-7.5, M8 11-15 N·m); that is a fallback for hardware with no specific spec, not a substitute for the rows below. Two documented gaps: the CS-590 operator's manual prints no muffler-bolt figure although the CS-400's does, and the CS-310/CS-352 were not checked.

Echo SRM-2620ES / SRM-2620TES25.4cc Manufacturer-published

series SRM-2620ES, SRM-2620TES; also Shindaiwa T262XS, C262S, T262TXS, C262TS
From the official Yamabiko/Echo service manual, section "1-3 Torque Limits". More about this engine ›

The table prints kgf-cm first, then N·m, then in-lbf — three units for every row, which means each value cross-checks against itself. This is the most complete published fastener table of any handheld engine on this site.

Fastener Torque Where it comes from
cutter fastener (left-hand thread)LM10 21–24 ft-lbHigh
28-32 N·m (280-320 kgf-cm). LEFT-HAND thread — it loosens clockwise. Why › The highest torque on the machine, and the one most often ruined by turning it the wrong way.
magneto rotor (flywheel)M8 12–15 ft-lbHigh
16-20 N·m (160-200 kgf-cm, 140-175 in-lbf). Why › Far below a 4-stroke crankshaft flywheel nut — a handheld magneto rotor is an M8 fastener, not the 125 ft-lb item on a Honda GX270.
spark plugM10 7–11 ft-lbHigh
10-15 N·m (100-150 kgf-cm, 87-130 in-lbf). Why › This is an M10 plug, which is why it takes roughly half what the M14 plug on a Stihl or Husqvarna chainsaw does. Match the figure to your plug thread, not to "2-stroke".
clutch shoeM6 62–97 in-lbHigh 7-11 N·m (70-110 kgf-cm, 60-95 in-lbf).
cylinder screwM5 62–97 in-lbHigh 7-11 N·m (70-110 kgf-cm). Cylinder and head are one casting on a 2-stroke — not a head-bolt sequence.
crankcase screwM5 62–97 in-lbHigh 7-11 N·m (70-110 kgf-cm).
mufflerM5 62–97 in-lbHigh 7-11 N·m (70-110 kgf-cm).
starter pawl assemblyM8 62–97 in-lbHigh 7-11 N·m (70-110 kgf-cm).
starter caseM5 35–53 in-lbHigh 4-6 N·m (40-60 kgf-cm).
muffler cover, crankcase sideM5 27–40 in-lbHigh 3-4.5 N·m (30-45 kgf-cm). Note this differs from the starter-side cover screw below — Echo gives the two sides different figures.
muffler cover, starter sideM5 22–31 in-lbHigh 2.5-3.5 N·m (25-35 kgf-cm). The lowest figure in the table.

Echo CS-40040.2cc Manufacturer-published

series CS-400
From the Echo CS-400 operator's manual on echo-usa.com, where these appear as formal "fastening torque" spec callouts rather than running… More about this engine ›

prose. Echo prints N·m, kgf-cm and lbf-in; the in-lb values below are Echo's own printed figures.

Fastener Torque Where it comes from
guide bar nut 175–200 in-lbHigh
20-23 N·m (200-230 kgf-cm) — about 15-17 ft-lb. Why › Echo is one of the few handheld manufacturers that publishes a guide-bar-nut figure at all; Husqvarna's workshop manuals do not.
spark plug 130–150 in-lbHigh 15-17 N·m — about 11-12.5 ft-lb. Printed by Echo as "fastening torque".
muffler mounting bolt / nut 70–95 in-lbHigh 8-11 N·m. Two-stage: tighten cold, then re-tighten after the saw has warmed up.

Echo CS-590 Timber Wolf59.8cc Manufacturer-published

series CS-590, CS-600P
From the Echo CS-590 operator's manual on echo-usa.com. More about this engine ›

The bar-nut and spark-plug figures are identical to the CS-400's despite the much larger engine — Echo uses one spec across the range for both.

Fastener Torque Where it comes from
guide bar nut 175–200 in-lbHigh 20-23 N·m — about 15-17 ft-lb. Same as the CS-400.
spark plug 130–150 in-lbHigh 15-17 N·m — about 11-12.5 ft-lb. Matches the CS-400 exactly.
1 spec not published — muffler mounting bolt / nut What we found ›
  • muffler mounting bolt / nutGAP: the CS-590 operator's manual prints no muffler-bolt torque, although the CS-400's does (8-11 N·m). The CS-400 figure is not carried over here — same brand is not the same engine, and this is a 59.8cc saw against a 40.2cc one.

Echo SRM-225 trimmer21.2cc Manufacturer-published

series SRM-225, SRM-225i; GT-225 shares the powerhead
From the Echo SRM-225 operator's manual on echo-usa.com. More about this engine ›

This manual prints kgf-cm and in-lbf only, with no N·m column — the N·m figures in the notes below are conversions from Echo's printed values, not Echo's own.

Fastener Torque Where it comes from
spark plug 130–150 in-lbHigh
150-170 kgf-cm as printed, which converts to 14.7-16.7 N·m. Why › Identical in-lbf figures to the CS-400 and CS-590 spark plug — a useful cross-check that Echo uses one plug spec across the range. Plug: NGK BPM-8Y.
muffler mounting bolt / nut 80–95 in-lbHigh 90-110 kgf-cm as printed, which converts to 9.0-10.7 N·m. Two-stage: tighten, run, re-tighten.

What is the spark plug torque on an Echo trimmer or chainsaw?

It depends on the plug thread, and Echo publishes both. The SRM-2620ES service manual specifies 10-15 N·m (about 7-11 ft-lb) for its M10 plug, while the CS-400, CS-590 and SRM-225 manuals all give 130-150 lbf-in (15-17 N·m, about 11-12.5 ft-lb). Either way an Echo plug takes roughly half what the M14 plug on a Stihl chainsaw does at 25 N·m. This is the clearest illustration on the site that "2-stroke spark plug torque" is not one number — match the figure to the plug thread on your machine.

What torque do Echo guide bar nuts take?

20-23 N·m — Echo prints it as 175-200 lbf-in — and the figure is the same on the 40cc CS-400 and the 59.8cc CS-590. Echo is unusual in publishing this at all: Husqvarna's workshop manuals for the 435 through 450 contain no guide-bar-nut torque anywhere. That makes Echo's number a useful sanity check on the 20-30 ft-lb bar-nut figures that circulate for other brands, which are 27-41 N·m — well above what the one manufacturer who does publish a spec considers right for the same joint.

Is the Echo trimmer cutter fastener a left-hand thread?

Yes. The SRM-2620ES service table lists it as LM10 with a left-hand thread, and it is the highest-torque fastener on the machine at 28-32 N·m (about 21-24 ft-lb). That combination — highest torque plus reverse thread — is why it is the fastener most often destroyed on these trimmers. It loosens clockwise. Confirm the direction before applying real force.

Why does Echo give two different muffler cover torques?

Because the two sides are different fasteners in different material. The SRM-2620ES table specifies 2.5-3.5 N·m for the starter-side cover screw and 3-4.5 N·m for the crankcase-side one — a real difference, not a rounding artifact, and both are low enough that only an in-lb wrench or a calibrated screwdriver can set them. The muffler itself is separate again at 7-11 N·m.

My Echo manual gives no torque for the bolt I am working on. What should I use?

Echo publishes a general fastener table for exactly that case: M3 0.6-1 N·m, M4 1.5-2.5, M5 2.5-4.5, M6 4.5-7.5 and M8 11-15 N·m. Use it only where there is no specific figure — a fastener that has its own row is not covered by the general table, and several on the SRM-2620ES (the cutter fastener at 28-32 N·m on an LM10, the magneto rotor at 16-20 N·m on an M8) sit well outside what the generic figure for their thread size would suggest.

Why is the muffler bolt torque missing for the CS-590?

Because Echo does not print it in that manual. The CS-400 operator's manual gives 8-11 N·m for its muffler bolts and the CS-590's does not give a figure at all. Rather than carry the CS-400 number across, this page records the gap: a 59.8cc saw and a 40.2cc saw are different engines, and borrowing a spec between them because the badge matches is the mistake these tables exist to prevent. Echo's general M5 figure (2.5-4.5 N·m) is not a substitute either, since the CS-400's own muffler spec sits above it.

Related lookups

Loading interactive lookup…