Exhaust Valve 32-016-01-S Fits Kohler CH25 CH730 CH740

One standard exhaust valve that fits the Kohler CH and CV twin engines, replacing 32-016-01-S. Note on numbering: 24-016-01-S was the original part number and is still what appears in a lot of service literature and on shop shelf labels. It was superseded to 32-016-01-S, and the factory parts note reads to use 32-016-01-S in its place, so both numbers lead to this valve. This listing supplies one valve. These V twins have two cylinders and two exhaust valves, so order two if both heads are being done. Fits CH18, CH20, CH22, CH23, CH25, CH26, CH730, CH740 and CH750 and the vertical shaft CV equivalents; identify the engine from the model and spec numbers on the blower housing decal. Related parts: the intake valve is 24-017-01-S standard, the 0.25mm oversize stem versions are 32-016-02-S exhaust and 24-017-02-S intake, and the valve stem seal is 25-032-14-S. If the cylinder head guide has already been reamed 0.25mm oversize, the oversize stem valve is the one you need rather than this standard one. On diagnosis: a burnt exhaust valve is usually the result of a receded seat, a worn guide letting the valve sit crooked, carbon holding it off the seat, or an engine run lean or hot, and a new valve fitted into a worn guide or onto a pitted seat will not last. Guide wear limit on the exhaust is 7.159mm against a new size of 7.038 to 7.058mm. Seat and face angle is 45 degrees and stem to guide clearance on the exhaust is 0.050 to 0.088mm. Lap the new valve until the seating ring is even, clean all lapping compound from the port and guide, and fit a new stem seal while the head is apart. These engines use hydraulic lifters, so there is no lash adjustment after assembly.

• ONE STANDARD EXHAUST VALVE PER ORDER - This is one valve. These twins have two cylinders and therefore two exhaust valves, so order two if you are doing both heads. Replaces 32-016-01-S. If your manual or your old parts list says 24-016-01-S, that is the superseded number for the same valve and the factory note reads to use 32-016-01-S in its place, so you are in the right place either way.
• BOTH NUMBERS, AND WHY THE OLD ONE IS HERE - 24-016-01-S was the original number and it still appears in service literature, on old parts tickets and on shop shelf labels, which is why it is on this page. It was superseded to 32-016-01-S. There is also a 0.25mm oversize stem version, 32-016-02-S, for a head whose guide has been reamed oversize. If your head has been reamed, that is the valve you want rather than this one.
• FITS KOHLER CH AND CV TWINS - CH18, CH20, CH22, CH23, CH25, CH26, CH730, CH740 and CH750, and the vertical shaft CV equivalents. Read the model and spec numbers off the blower housing decal. The matching intake valve is 24-017-01-S standard, or 24-017-02-S with the 0.25mm oversize stem, and the valve stem seal is 25-032-14-S. Exhaust valves work harder than intakes on these engines and usually fail first, which is why they are sold singly.
• WHY A VALVE BURNS, AND WHAT TO FIX WITH IT - A burnt exhaust valve is a symptom. The usual causes are a receded seat, a guide worn enough to let the valve sit crooked, carbon holding it off the seat, or an engine run lean or hot. A new valve in a worn guide or on a pitted seat buys a few hours. Check guide wear with a dial indicator, recut the seat, and lap the valve in. Guide wear limit on the exhaust is 7.159mm against a new size of 7.038 to 7.058mm.
• SETTING IT UP - Seat and face angle is 45 degrees. Stem to guide clearance on the exhaust is 0.050 to 0.088mm. Lap until the seating ring is even all the way round, then clean every trace of compound out of the port and guide. These engines use hydraulic lifters, so there is no lash to set, but turn the engine over by hand before the first start. Fit a new stem seal while the head is apart and check the gasket surface for flatness.