Honda GX Series Engine Torque Specs

This is genuine manufacturer-doc-grade sourcing throughout.

(GX160)" reference sheet that cross-confirms the same numbers.

honda-engines-eu.com) restates by name for GX240. The supplement's own preface says it covers "the Honda GX240R2/RT2/T2/U2/UT2 and GX340R2/RT2/T2/U2/UT2 engines" and routes anything it doesn't cover to "the GX390RT2/T2/UT2 base shop manual (part number 62Z5F00) and GX270T2/UT2 supplement (part number 62Z5F00Z)" -- so cylinder head bolt, connecting rod bolt, rocker arm, crankcase cover bolt and oil drain plug are not printed under a GX240 heading in any of the three linked documents and are recorded as gaps rather than carried over from GX390. Honda EU's GX240 documents print 270 cm3/77x58mm (GX270's figures) -- both 62Z5F00X p.1-7 and the separate technical-sheet-gx240-v26.pdf p.4 agree with each other on this. Honda's US GX240 specification is 242 cm3/73x58mm; not re-fetched in this pass. Either way, this does not affect the p.2-4 torque table. Honda's Standard Torque Values table (62Z5F000, p.2-4) covers any small fastener not individually listed, by thread size: 6mm bolt/nut 7 lbf-ft, 8mm 16 lbf-ft, 10mm 25 lbf-ft, 12mm 40 lbf-ft.

Motor Co. 2010/2017), which explicitly names GX270 and covers flywheel, connecting rod and cylinder head bolt; and the GX270-specific service information supplement (Honda P/N 62Z5F00Z, June 2010) for the flywheel-nut correction below. Rocker-arm figures still cite the GX340/GX390 assembly sheet (cf.hondappsv.com, © Honda Motor Co. 2009), which doesn't restate GX270 by name -- flagged medium confidence on that row for that reason. Valve clearance and displacement/torque-output specs come from Honda's official GX270/GX390 owner's manual.

honda-engines-eu.com) restates by name for GX340. The supplement's own preface routes anything it doesn't cover to "the GX390RT2/T2/UT2 base shop manual (part number 62Z5F00) and GX270T2/UT2 supplement (part number 62Z5F00Z)" -- GX340's flywheel figure happens to match GX390's exactly. Cylinder head bolt is separately sourced below from an older, K1-generation Honda assembly sheet that names GX340 directly (a fourth document, not one of the three 62Z5F00X routes to); the remaining fasteners are not printed for GX340 in any document found, so they are recorded as gaps. Honda EU's 62Z5F00X p.1-8 spec page prints 389 cm3 / 88x64mm under its GX340 heading -- that is GX390's displacement/bore, a labelling error in that document; it does not affect the p.2-4 torque table. Honda's Standard Torque Values table (62Z5F000, p.2-4) covers any small fastener not individually listed, by thread size: 6mm bolt/nut 7 lbf-ft, 8mm 16 lbf-ft, 10mm 25 lbf-ft, 12mm 40 lbf-ft.

bolt and spark plug instead cite the GX390 base manual (62Z5F000) directly, since it names GX390 in its own table rather than a combined diagram sheet. Bore x stroke 88.0x64.0mm.

manual (Honda P/N 62Z6N000, June 2009, honda-engines-eu.com) with one shared torque table for the whole family, cross-confirmed against the engine-assembly diagram sheet for the cylinder nut and flywheel nut rows. All three share the same 688.0 cm3 block (Doc A p.1-3, printed exactly, not a rounded nameplate number); only power/torque-output tuning differs across the three model numbers, not fastener torque. No head bolts carry a published torque on this V-twin: Honda uses four M10x1.25 cylinder nuts per cylinder instead of a head-bolt joint -- Honda's own lubrication table (p.2-5) lists this location as "cylinder nut and bolt threads and seating surface." Honda's own torque table names the fastener "Cylinder nut"; it is labeled "cylinder head nuts" below since it is the head-equivalent joint. Unlisted small fasteners follow Honda's Standard Torque Values table (62Z6N000, p.2-4) by thread size: 5mm bolt/nut 3.8 lbf-ft, 6mm 7 lbf-ft, 8mm 16 lbf-ft, 10mm 25 lbf-ft, 12mm 40 lbf-ft.