All dimensions in inches.
| Model (Horsepower) | K91 (4) | K161 (7) | K181 (8) | K241 (10) | K301 (12) | K321 (14) | K341 (16) | |||
| General | Bore x Stroke | 2.375 x 2.000 | 2.938 x 2.500 | 2.938 x 2.750 | 3.251 x 2.875 | 3.375 x 3.250 | 3.500 x 3.250 | 3.750 x 3.250 | ||
| Displacement Cu. In. | 8.86 | 16.94 | 18.64 | 23.85 | 29.07 | 31.27 | 35.90 | |||
| Max. Operating RPM | 4000 | 3600 | 3600 | 3600 | 3600 | 3600 | 3600 | |||
|
Balance Gear |
Shaft O.D. | New | - | - | - | .4998/.5001 | .4998/.5001 | .4998/.5001 | .4998/.5001 | |
| Max Wear Limit | - | - | - | .4996 | .4996 | .4996 | .4996 | |||
| End Play | - | - | - | .002/.010 | .002/.010 | .002/.010 | .002/.010 | |||
| Camshaft | End Play | .005/.020 | .005/.010 | .005/.010 | .005/.010 | .005/.010 | .005/.010 | .005/.010 | ||
|
Connecting Rod |
Running Clearance |
Rod to Crankpin (New) | .001/.0025 | .001/.002 | .001/.002 | .001/.002 | .001/.002 | .001/.002 | .001/.002 | |
| Rod to Crankpin Wear Limit | .003 | .0025 | .0025 | .0025 | .0025 | .0025 | .0025 | |||
| Rod to Piston Pin (New) | .0007/.0008 | .0006/.0011 | .0006/.0011 | .0003/.0008 | .0003/.0008 | .0003/.0008 | .0003/.0008 | |||
| Small End I.D. (New) | .5630/.5633 | .6255/.6258 | .6255/.6258 | .8596/.8599 | .8757/.8760 | .8757/.8760 | .8757/.8760 | |||
| Crankshaft |
Main PTO & Flywheel End O.D. |
New | .9841/.9844 | 1.1811/1.1814 | 1.1811/1.1814 | 1.5745/1.5749 | 1.5745/1.5749 | 1.5745/1.5749 | 1.5745/1.5749 | |
| Max. Wear Limit | .9841 | 1.1811 | 1.1811 | 1.5745 | 1.5745 | 1.5745 | 1.5745 | |||
|
Crankpin |
New | .9360/.9355 | 1.1860/1.1855 | 1.1860/1.1855 | 1.5000/1.4995 | 1.5000/1.4995 | 1.5000/1.4995 | 1.5000/1.4995 | ||
| Max. Wear Limit | .9350 | 1.1850 | 1.1850 | 1.4990 | 1.4990 | 1.4990 | 1.4990 | |||
| Max. Out of Round | .0005 | .0005 | .0005 | .0005 | .0005 | .0005 | .0005 | |||
| Max. Taper | .001 | .001 | .001 | .001 | .001 | .001 | .001 | |||
| End Play | .004/.023 | .002/.023 | .002/.023 | .003/.020 | .003/.020 | .003/.020 | .003/.020 | |||
| Cylinder Bore | Inside Diameter | New | 2.3755/2.3745 | 2.9380/2.9370 | 2.9380/2.9370 | 3.2515/3.2505 | 3.3755/3.3745 | 3.5005/3.4995 | 3.7505/3.7495 | |
| Max. Wear Limit | 2.378 | 2.941 | 2.941 | 3.254 | 3.378 | 3.503 | 3.753 | |||
| Max. Out of Round | .003 | .003 | .003 | .003 | .003 | .003 | .003 | |||
| Max. Taper | .003 | .003 | .003 | .002 | .002 | .002 | .002 | |||
| Cylinder Head | Max. Out of Flatness | .003 | .003 | .003 | .003 | .003 | .003 | .003 | ||
| Ignition | Spark Plug Type & Gap | Type2 | RCJ-8 | RCJ-8 | RCJ-8 | RH-10 | RH-10 | RH-10 | RH-10 | |
| Battery | .025 | .025 | .025 | .035 | .035 | .035 | .035 | |||
| Magneto | .025 | .025 | .025 | .025 | .025 | .025 | .025 | |||
| Gaseous Fuels | .018 | .018 | .018 | .018 | .018 | .018 | .018 | |||
| Nominal Point Gap | .020 | .020 | .020 | .020 | .020 | .020 | .020 | |||
| Model (Horsepower) | K91 (4) | K161 (7) | K181 (8) | K241 (10) | K301 (12) | K321 (14) | K341 (16) | |||
| All Pistons | Service Replacement Sizes | .003 - .010 - .020 - .030 | ||||||||
 |
Thrust Face O.D.3 | New | 2.371/2.369 | 2.9297/2.9281 | 2.9297/2.9281 | 3.2432/3.2413 | 3.368/3.365 | 3.4941/3.4925 | 3.7425/3.7410 | |
| Max. Wear Limits | 2.366 | 2.925 | 2.925 | 3.238 | 3.363 | 3.491 | 3.738 | |||
| Thrust Face to Bore Clearance (New)1 | .0035/.006 | .007/.010 | .007/.010 | .007/.010 | .007/.010 | .007/.010 | .007/.010 | |||
| Ring End Gap | New Bore | .007/.017 | .007/.017 | .007/.017 | .010/.020 | .010/.020 | .010/.020 | .010/.020 | ||
| Used Bore (Max.) | .027 | .027 | .027 | .030 | .030 | .030 | .030 | |||
| Max. Ring side Clearance | .006 | .006 | .006 | .006 | .006 | .006 | .006 | |||
 |
Thrust Face O.D.5 |
New | - | - | - | - | - | - | 3.7465/3.7455 | |
| Max. Wear Limits | - | - | - | - | - | - | 3.744 | |||
| Thrust Face to Bore Clearance (New)1 | - | - | - | - | - | - | .0030/.0050 | |||
| Ring End Gap | New Bore6 | - | - | - | - | .010/.020 | ||||
| Used Bore (Max.)6 | - | - | - | - | - | - | .030 | |||
| Max. Ring Side Clearance | - | - | - | - | - | - | .004 | |||
 |
Thrust Face O.D.5 |
New | - | - | 2.9329/2.9336 | - | 3.3700/3.3693 | 3.4945/3.4938 | 3.7433/3.7426 | |
| Max. Wear Limits | - | - | 2.931 | - | 3.367 | 3.492 | 3.7406 | |||
| Thrust Face to Bore Clearance (New)1 | - | - | .0034/.0051 | - | .0045/.0062 | .0050/.0067 | .0062/.0079 | |||
| Ring End Gap | New Bore6 | - | - | .010/.023 | - | .010/.020 | .010/.020 | .013/.025 | ||
| Used Bore (Max.)6 | - | - | .032 | - | .030 | .030 | .033 | |||
| Max. Ring Side Clearance | - | - | .006 | - | .006 | .006 | .004 | |||
| Model (Horsepower) | K91 (4) | K161 (7) | K181 (8) | K241 (10) | K301 (12) | K321 (14) | K341 (16) | |||
| Piston Pin | Outside Diameter | .5623/.5625 | .6247/.6249 | .6247/.6249 | .8591/.8593 | .8752/.8754 | .8752/.8754 | .8752/.8754 | ||
| Valves | Guide Reamer Size | .250 | .3125 | .3125 | .3125 | .3125 | .3125 | .3125 | ||
|
Tappet Clearance (Cold) |
Intake | .005/.009 | .006/.008 | .006/.008 | .008/.010 | .008/.010 | .008/.010 | .008/.010 4 | ||
| Exhaust | .011/.015 | .017/.019 | .017/.019 | .017/.019 | .017/.019 | .017/.019 | .017/.019 | |||
|
Minimum Lift (Zero Lash) |
Intake | .2035 | .2718 | .2718 | .318 | .318 | .318 | .318 | ||
| Exhaust | .1768 | .2482 | .2482 | .318 | .318 | .318 | .318 | |||
|
Minimum Valve Stem O.D. |
Intake | .2478 | .3103 | .3103 | .3103 | .3103 | .3103 | .3103 | ||
| Exhaust | .2458 | .3088 | .3088 | .3074 | .3074 | .3074 | .3074 | |||
| Nominal Angle Valve seat | 45o | 45o | 45o | 45o | 45o | 45o | 45o | |||
|
Guide I.D. Max. Wear Limit1 |
Intake | .005 | .005 | .005 | .006 | .006 | .006 | .006 | ||
| Exhaust | .007 | .007 | .007 | .008 | .008 | .008 | .008 | |||
1Subtract
O.D. of inner part from I.D. of outer part.
2Champion
spark plugs or equivalent
3Measure
just below oil ring groove and at right angles to piston pin
41800
RPM generator sets .005/ 007.
5Measure
1/2" above the bottom of the piston skirt
6Top
and center compression rings