Re-ring and reseal package for the 83mm Kohler twin-cylinder engines. Two Style B piston ring sets, one for each cylinder, replacing 25-108-02-S, plus a complete gasket and seal set and both crankshaft seals. Rings and gaskets only; no pistons are supplied, so the ring style has to match the pistons already in the engine. Style B uses a 1.2mm top ring: measure the old top ring or the top piston groove, and if it reads 1.5mm you have Style A pistons and need 24-108-15-S instead. These rings are the +0.08mm step, about three thousandths of an inch over the 83.00mm standard bore and the smallest oversize offered, for a cylinder still near standard with light wear. If the block has been machined to a true oversize, order the ring set matching the bore the shop cut. Covers the CH25, CH26, CH730, CH735, CH740, CH745, CH750 and CH752, the vertical-shaft CV25, CV26, CV730, CV735, CV740, CV745 and CV750, and the SV710 through SV740 and SV810 through SV840. Before fitting, measure the bore for taper and out of round, check end gap and groove side clearance, and leave a honed finish for the rings to seat against.
- TWO RING SETS AND A FULL GASKET SET - NO PISTONS - Two Style B ring sets, one per cylinder, replacing 25-108-02-S, with a complete gasket and seal set and both crankshaft seals. The pistons stay in the engine, which is why the ring style below has to be checked.
- MEASURE YOUR TOP RING - 1.2MM IS THIS KIT - Style B takes a 1.2mm top ring and Style A takes 1.5mm. Lay a caliper across the old top ring or the top groove. If it reads 1.5mm you have Style A pistons and need 24-108-15-S instead.
- PLUS 0.08MM, ABOUT .003 INCH - Kohler sizes its oversizes in millimeters: standard, +0.08mm, +0.25mm and +0.50mm. This is the smallest step, for a cylinder close to the 83.00mm standard with light wear, where a standard set leaves the end gap wide. A bored block needs the set for the size it was cut to.
- FITS THE 83MM KOHLER TWINS - CH25, CH26, CH730, CH735, CH740, CH745, CH750 and CH752; CV25, CV26, CV730, CV735, CV740, CV745 and CV750; SV710 through SV740 and SV810 through SV840. Read the model and spec numbers off the blower housing decal.
- CHECK THE CYLINDER BEFORE THE RINGS GO IN - Measure the bore for taper and out of round first; past a few thousandths of taper the block needs boring and pistons instead. Check end gap in the bore each ring will run in and side clearance in the groove, hone so the rings bed in, and clean the oil pan face to bare metal before the sealant goes on.