Briggs & Stratton Engine Torque Specs

Cylinder head bolt torque at a glance

HighMediumLow= how many independent sources agree

Check the unit before you set the wrench. Briggs prints cylinder-head, connecting-rod and cover torque in inch-pounds (in-lb); the flywheel nut is in foot-pounds (ft-lb). On a foot-pound wrench, divide in-lb by 12: 140 in-lb is 11.7 ft-lb — setting 140 ft-lb is twelve times the spec.

Briggs & Stratton fastener torque varies by engine family and even by model-series number, not by horsepower. These specs come straight from Briggs & Stratton's own “Check Chart” service documents (form MS-3992 and its per-platform siblings), extracted directly from the… Read the rest ›

manufacturer PDFs — so the flywheel-nut, cylinder-head, and connecting-rod numbers are grouped by the model-series ranges Briggs actually uses.

Where these numbers come from. 54 published figures, 6 confirmed gaps, every source named. How we checked ›

Values for the classic L-head, Intek single-cylinder OHV, Intek V-twin, and Vanguard V-twin families are extracted from official Briggs & Stratton Check Charts. The Quantum and EXi lines have no located manufacturer torque chart — they are shown as gaps rather than back-filled from a different design generation. One Intek V-twin source lists the flywheel torque with an “in-lb” unit label that its own N·m value contradicts; that row is flagged so you don't trust the mislabeled unit.

Classic L-Head / Flathead (3-5 HP class) Manufacturer-published

series 60000, 80000, 90000, 10A000-10M000, 110000, 120000, 130000 (aluminum/cast-sleeve); 170000, 171700, 190000, 191700, 220000/250000, 280000 (larger L-head aluminum); 230000, 240000, 320000 (L-head cast iron)
This is Briggs & Stratton's own official "Check Chart" -- form MS-3992, common specifications for all single-cylinder L-head engines. More about this engine ›

Extracted directly from the manufacturer PDF (not a paraphrase). Torque values are grouped: model series 60000 through 130000 share identical fastener torques; 170000-280000 aluminum step up; cast-iron 230000/240000/320000 step up further.

Fastener Torque Where it comes from
flywheel nut (model series 60000-130000, e.g. 3-5 HP) 55 ft-lbHigh —
cylinder head, in-lb (model series 60000-130000) 140 in-lb≈ 11.7 ft-lbHigh —
connecting rod torque (model series 60000-130000) 100 in-lb≈ 8.3 ft-lbHigh —
crankcase cover/sump (model series 60000-120000) 90 in-lb≈ 7.5 ft-lbHigh —
crankcase cover/sump (model series 130000) 120 in-lb= 10 ft-lbHigh 130000 (5 HP) steps up from the 90 in-lb used on smaller series in this family.
flywheel nut (model series 170000/171700/190000/191700) 65 ft-lbHigh —
cylinder head, in-lb (model series 170000/171700) 165 in-lb≈ 13.8 ft-lbHigh —
connecting rod torque (model series 170000/171700) 165 in-lb≈ 13.8 ft-lbHigh —
cylinder head, in-lb (model series 190000/191700, ~8 HP) 165 in-lb≈ 13.8 ft-lbHigh —
connecting rod torque (model series 190000/191700) 185 in-lb≈ 15.4 ft-lbHigh —
flywheel nut (model series 220000/250000) 65 ft-lbHigh —
flywheel nut (model series 280000, L-head aluminum) 85 ft-lbHigh —
cylinder head, in-lb (model series 280000) 185 in-lb≈ 15.4 ft-lbHigh —
connecting rod torque (model series 280000, both rod screws same size) 185 in-lb≈ 15.4 ft-lbHigh
This series uses either two same-size rod screws (185 in-lb each) OR a small+large screw pair torqued differently: small screw first to 160… Why › in-lb, large screw second to 260 in-lb. See Fig. 1 in the source chart.
flywheel nut (L-head cast iron, model series 230000/240000/320000, e.g. 10-16 HP) 145 ft-lbHigh —
cylinder head, in-lb (L-head cast iron 230000/240000/320000) 190 in-lb≈ 15.8 ft-lbHigh —
connecting rod torque (L-head cast iron 230000/240000/320000) 190 in-lb≈ 15.8 ft-lbHigh —
crankcase cover/sump (L-head cast iron 230000/240000/320000, Mag & PTO side) 90 in-lb≈ 7.5 ft-lbHigh PTO-side cover listed separately at 190 in-lb in the source chart; Mag side is 90 in-lb.
sump screw torque (universal, integral washer/dog-point style) 140 in-lb≈ 11.7 ft-lbHigh
200 in-lb variant applies to sump screws with a loose washer + thread sealant, per the chart's Fig. 1 callout. Why › Use 140 in-lb for integral-washer dog-point screws.

Valve clearance — feeler gauge, not a wrench

  • valve clearance intake, cold (model series 60000-120000): Not a torque spec -- clearance value: .006-.010 in.
  • valve clearance exhaust, cold (model series 60000-120000): Not a torque spec -- clearance value: .005-.007 in.

L-Head Opposed Twin Cylinder (classic twin flathead) Manufacturer-published

series 400000, 420000, 460000

Older opposed-twin flathead family (predates the Vanguard/Intek V-twin OHV designs below). From the same official B&S Check Chart.

Fastener Torque Where it comes from
flywheel nut 145 ft-lbHigh —
cylinder head, in-lb 160 in-lb≈ 13.3 ft-lbHigh —
connecting rod torque 190 in-lb≈ 15.8 ft-lbHigh —
crankcase cover/sump 225 in-lb≈ 18.8 ft-lbHigh —

Quantum (single OHV push-mower engine) Manufacturer-published

series 12H800-12H899, 12J800, 12S800, 12T800, 122K00, 123K00, 129800 and similar "12x800"/"12xK00" numeric-suffix series (4-6.5 HP vertical-crankshaft, side-valve/L-head walk-behind mower engines)
PARTLY RESOLVED (2026-08). There is still no Briggs chart headed "Quantum" -- the nameplate is marketing language that does not appear in… More about this engine ›

Briggs' own repair manuals. What was located is the bucket underneath it: Briggs publishes an L-head Check Chart row for model series 120000, and Briggs' own parts catalog treats 120000-12Z999 as one range, which is where the Quantum model numbers fall. Four fastener figures below now come from that chart, cross-checked against Briggs' separate metric-only chart. They are graded medium rather than high for one specific reason: the identification of Quantum with the 120000 row rests on the model-number range, not on any document naming the engine, and the primary manual 270962 itself could not be read directly -- only Briggs' derived charts of it. Community forum posts confirm general figures like 140 or 165 in-lb for head bolts on "many" B&S engines but do not tie a number specifically and confidently to Quantum. Do not apply the classic-L-head numbers above to Quantum without verifying the exact model/type/code against a repair manual looked up by full model number at briggsandstratton.com -- Quantum is a later (1990s-2000s), higher-volume design and its fastener specs are not guaranteed to match the older flathead family.

Fastener Torque Where it comes from
cylinder head bolts 140 in-lb≈ 11.7 ft-lbMedium
15.8 N·m (converted -- the L-head Check Chart prints in-lb only for this row). Why › Medium rather than high confidence for the reason given in the engine note: the figure is Briggs' own, but published against the 120000 model bucket rather than the "Quantum" nameplate.
flywheel nut 55 ft-lbMedium
75 N·m. This row has an independent cross-check: Briggs' metric-only chart (form MS-3992MET) lists 75 Nm for the same L-head 120000 row, and… Why › 55 ft-lb converts to 74.6 N·m -- two separate Briggs documents agreeing in different units. Use a flywheel holding tool, not an impact gun.
connecting rod bolts 100 in-lb≈ 8.3 ft-lbMedium 11.3 N·m (converted -- chart prints in-lb only).
crankcase cover / sump bolts 85 in-lb≈ 7.1 ft-lbMedium 9.6 N·m (converted -- chart prints in-lb only).
2 specs not published — spark plug, oil drain plug What we found ›
  • spark plugGAP: still not published. The L-head Check Chart that supplies the four figures above has no spark-plug row, so unlike them this one has no Briggs document behind it at any confidence. The Intek single-cylinder entry's 180 in-lb is the nearest same-era B&S reference point and is NOT confirmed for this family.
  • oil drain plugGAP: no figure in the L-head Check Chart for this fastener.

Intek Single-Cylinder OHV Manufacturer-published

series 110400, 110600, 111400, 111600, 113400, 120400, 120600, 121400, 121600, 122600, 123400, 123600, 28S700, 311700
From B&S's own official "CHECK CHART - COMMON SPECIFICATIONS FOR ALL SINGLE CYLINDER INTEK ENGINE MODELS" PDF -- a dedicated per-nameplate… More about this engine ›

manufacturer chart. Model series 110400-123600 (roughly 3.5-6.75 HP class) share one torque profile; 28S700/311700 (larger, ~11-13 HP Intek singles) share a second, higher profile.

Fastener Torque Where it comes from
flywheel nut (model series 110400-123600) 60 ft-lbHigh 81 N-m equivalent per the official chart.
cylinder head (model series 110400-123600) 210 in-lb≈ 17.5 ft-lbHigh 24.0 N-m equivalent.
connecting rod (model series 110400-123600) 100 in-lb≈ 8.3 ft-lbHigh 11.0 N-m equivalent.
cover or sump (model series 110400-123600) 110 in-lb≈ 9.2 ft-lbHigh 12.0 N-m equivalent.
flywheel nut (model series 28S700/311700, larger Intek singles) 100 ft-lbHigh
135 N·m, as printed. Briggs' own repair manual 276781 prints "Flywheel Nut 100 lb-ft. Why › (135 Nm)" verbatim on both the MODEL 280000 and MODEL 310000 vertical-series spec pages, and Briggs' metric-only chart (form MS-3992MET) independently lists 135 Nm for both rows. This row previously carried a note reading "88.0 N-m equivalent", which was wrong: 88 N·m is the starter clutch (65 lb-ft), the only OTHER lb-ft row on that same manual page — the flywheel nut's imperial figure had been paired with the starter clutch's metric one. A widely-mirrored third-party Intek chart reproduces the same 100 ft-lb / 88 N·m pairing, which is the likely route in. The ft-lb figure was always right; do not "correct" it downward to match the bad note.
cylinder head (model series 28S700/311700) 220 in-lb≈ 18.3 ft-lbHigh 25.0 N-m equivalent.
connecting rod (model series 28S700/311700) 150 in-lb≈ 12.5 ft-lbHigh 17.0 N-m equivalent.
cover or sump (model series 28S700/311700) 210 in-lb≈ 17.5 ft-lbHigh
16.0 N-m equivalent (chart shows both 16.0 Nm and 210 in-lb -- minor internal N-m/in-lb rounding mismatch in the source document itself; the… Why › in-lb figure is what a US mechanic should use).

Valve clearance — feeler gauge, not a wrench

  • valve clearance intake, cold (model series 110400/111400/113400/120400/121400/123400): Not a torque spec -- clearance value: .004-.006 in.
  • valve clearance intake, cold (model series 110600/111600/120600/121600/122600/123600): Not a torque spec -- clearance value: .004-.008 in.
  • valve clearance, cold (model series 28S700/311700): Not a torque spec -- clearance values: intake .003-.005 in, exhaust .005-.007 in.

Intek V-Twin OHV Manufacturer-published

series 405777 (40 cu-in / 656cc), 445777 (44.2 cu-in / 724cc)
From B&S's own official "COMMON SPECIFICATIONS FOR INTEK V-TWIN OHV ENGINES" PDF, which includes a full fastener torque table by… More about this engine ›

wrench/socket size. All figures below are directly from that manufacturer document.

Fastener Torque Where it comes from
head bolts 220 in-lb≈ 18.3 ft-lbHigh 1/2" socket. 25.0 N-m equivalent.
connecting rod 100 in-lb≈ 8.3 ft-lbHigh 5/16" socket. 11.2 N-m equivalent.
flywheel 150 ft-lbMedium⚠ sources disagree
The source PDF literally prints "150 in. Why › Lbs. (203Nm)" -- but 203 N-m converts to ~150 ft-lb, not 150 in-lb (150 in-lb would be ~17 N-m). This looks like a unit typo in B&S's own document (in-lb where ft-lb was meant). Recorded here as ft-lb because that's the value consistent with the stated N-m figure and with a 1-1/4" wrench flywheel nut of this size class; flagged so downstream editors don't silently trust "in-lb" at face value.
spark plug 180 in-lb= 15 ft-lbHigh 5/8" deep socket. 20.0 N-m equivalent.
oil drain plug 125 in-lb≈ 10.4 ft-lbHigh 3/8" square drive (internal). 14.0 N-m equivalent.
valve cover 100 in-lb≈ 8.3 ft-lbHigh 3/8" socket. 11.2 N-m equivalent.
rocker arm 100 in-lb≈ 8.3 ft-lbHigh 8mm socket. 11.2 N-m equivalent.
rocker arm lock nut 60 in-lb= 5 ft-lbHigh 13mm socket. 6.6 N-m equivalent.

Valve clearance — feeler gauge, not a wrench

  • valve clearance, cold (both intake and exhaust): Not a torque spec -- clearance value: .004-.006 in.

Vanguard OHV V-Twin Manufacturer-published

series 290000, 303000, 350000, 351000, 380000 (common torque specs shared across all models per the manufacturer chart)
From B&S's own official "VANGUARD OHV V-TWIN CYLINDER ENGINE MODELS - COMMON SPECIFICATIONS - ALL MODELS" PDF. More about this engine ›

Unlike Intek, Vanguard's chart states these torque values apply uniformly across the whole model range, not tiered by displacement.

Fastener Torque Where it comes from
cylinder head 165 in-lb≈ 13.8 ft-lbHigh 19.0 N-m equivalent.
connecting rod 115 in-lb≈ 9.6 ft-lbHigh 13.0 N-m equivalent.
flywheel 125 ft-lbHigh 175.0 N-m equivalent -- unit-consistent (unlike the Intek V-Twin flywheel entry above).
spark plug 200 in-lb≈ 16.7 ft-lbHigh 23.0 N-m equivalent.
crankcase cover 150 in-lb≈ 12.5 ft-lbHigh 17.0 N-m equivalent.
valve cover 25 in-lb≈ 2.1 ft-lbHigh 3.0 N-m equivalent.
rocker arm stud (current style) 100 in-lb≈ 8.3 ft-lbHigh 11.0 N-m equivalent.
rocker arm stud (early style) 140 in-lb≈ 11.7 ft-lbHigh 16.0 N-m equivalent.
rocker arm lock nut 65 in-lb≈ 5.4 ft-lbHigh
7.0 N-m equivalent. Note: a secondary source (JustAnswer, model 380000/23hp) reports 70 in-lb for the same fastener -- close enough to be… Why › rounding, not flagged as a hard conflict.
intake manifold 140 in-lb≈ 11.7 ft-lbHigh 16.0 N-m equivalent.
exhaust manifold 150 in-lb≈ 12.5 ft-lbHigh 17.0 N-m equivalent.

Valve clearance — feeler gauge, not a wrench

  • valve clearance, cold (both intake and exhaust): Not a torque spec -- clearance value: .004-.006 in.

EXi Series (modern low-maintenance single OHV, e.g. EXi625/725/875)

series 104M00, 125P00 and similar current-production series (approx. 2020s introduction)
GAP: EXi is Briggs & Stratton's current (as of this research, 2026) push-mower engine line built around "Just Check & Add" (no scheduled oil… More about this engine ›

changes). It is new enough that none of the classic aggregator sites (mymowerparts.com, smallenginesuppliers.com) that host the older official Check Chart PDFs have a dedicated EXi torque chart, and no EXi-specific repair-manual torque table was located. A re-check in 2026-08 found a plausible LEAD and deliberately did not use it: Briggs' "110000/120000 Professional Series" manual (part no. 279000-3/11) describes the same ReadyStart thermostatic-choke carburetor the EXi platform uses and prints a full torque table (flywheel nut 60 lb-ft/81 N·m, cylinder head 210 lb-in, connecting rod 95 lb-in, sump 110 lb-in, spark plug 180 lb-in, oil drain 145 lb-in). But that manual never names EXi, 725EXi, 875EXi, 104M02 or 122M02 anywhere in its 77 pages, and a bore-diameter cross-check came out ambiguous rather than confirming -- 104M02's bore matches the manual's 120000 section, not the 110000 one its "10" prefix would suggest, so Briggs' model-number-to-family mapping is not reliable for this letter-coded generation. Publishing those figures as EXi specs would be exactly the borrowed-number substitution this dataset exists to avoid. B&S's own EXi marketing pages give engine *output* torque ratings (e.g. 7.25 ft-lb gross torque @ 2600 rpm per SAE J1940) which is a performance spec, NOT a fastener torque -- do not confuse the two. If accurate EXi fastener specs are needed, the only reliable path is looking up the full model/type/code on briggsandstratton.com's manual finder for the specific unit in hand.

No published torque figures for this engine. Every source we checked is under “What we found” below.
4 specs not published — cylinder head bolts, flywheel nut, connecting rod, oil drain What we found ›
  • cylinder head boltsGAP -- no confirmed EXi-specific figure found.
  • flywheel nutGAP -- no confirmed EXi-specific figure found.
  • connecting rodGAP -- no confirmed EXi-specific figure found.
  • oil drainGAP -- EXi's headline feature is eliminating scheduled oil changes ("Just Check & Add"), which makes the drain-plug torque spec less commonly documented/needed by consumers; still, no figure was located.

How do I find the right Briggs & Stratton torque spec for my engine?

Read the model-series number stamped on the engine (e.g. 120000, 190000, 280000) — Briggs groups torque specs by model-series range, not by horsepower. Match that number to the family below: series 60000–130000 share one set of numbers, 170000–280000 step up, and the cast-iron 230000/240000/320000 engines step up further.

What is the flywheel nut torque on a Briggs & Stratton engine?

It depends on the family: ~55 ft-lb on the small aluminum L-head engines (series 60000–130000), 65 ft-lb on the mid-size aluminum series, 85 ft-lb on series 280000, and up to 145 ft-lb on the cast-iron L-head engines. Use the flywheel-nut row for your exact model series.

Why are some Briggs torque values in inch-pounds?

Briggs lists smaller fasteners — cylinder head, connecting rod, crankcase cover — in inch-pounds (in-lb) and the flywheel nut in foot-pounds. Divide in-lb by 12 to convert to ft-lb (140 in-lb ≈ 11.7 ft-lb). The tables keep Briggs' original units so they match the service chart.

What's the head bolt torque on a Briggs Intek OHV engine?

The Intek single-cylinder and V-twin OHV families have their own dedicated Check Charts with head-bolt torque sequences — see the Intek tables below. Do not use the classic L-head flathead numbers on an Intek; the head design and bolt pattern are different.

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