Models D,E,F,G,H,S 1-1/2 to 12HP
Also Economy, Jaeger, etc.
We can't guess how many jobber's sold Hercules engines but the above were the most popular. Parts on this page are for the models listed above. However, some of these parts will also fit the not so common 'N' (contact us for more info). Use these links for the JI/JK and XI/XK parts listings. We do not have a listing for Thermoil. When ordering parts for Hercules please give the HP and the letter with it off the serial tag on the top of the engine (Jaeger engines have an extra plate on the lower side of the block-do not use info off of this tag for ordering). Here are some other notes that may be helpful to you.

No Serial Plate? Give us the diameter of piston and we'll ask you a few questions to determine HP, etc.

1-1/2 to 2HP Cyl. blocks and caps have a double liner for the main bearing, one is a factory installed poured liner, not replaceable, and must be poured. The replaceable insert sits in this (APPLIES ONLY TO 1-1/2 to 2HP engines).

History of Hercules by Glen Karch 1914-1934 This 20 year period is when most of the engines in collector's hands were made. Although this book is on Hercules engines it is good reading for anyone.

Part# Description Price
L25 Instruction & Parts, 1-1/2 to 12HP, 64 pages 9.90
L270 History of Hercules by Glen Karch 11.00
L271 Serial number list 1.10
L076 Instruction & Parts, Economy 1-1/2 to 12HP, 1926 4.40
HM302 Bearing, Rod 1-1/2 to 2HP 25.05
HM3021 Bearing, Rod 2 to 2-1/2HP (cly bore 3-5/8") 37.50
HM3022 Bearing, Rod 2-1/2 to 3-1/2HP 45.00
HM3023 Bearing, Rod 5-6HP 57.50
HM3024 Bearing, Rod 7-8HP 72.50
HM3025 Bearing, Rod 9HP 82.50
HM3026 Bearing, Rod 12HP 160.00
HM303 Bearing, Main, 1-1/2 to 2HP 30.55
HM3031 Bearing, Main, 2 to 2-1/2HP (cyl. bore 3-5/8") 42.50
HM3032 Bearing, Main, 2-1/2 to 3HP 51.00
HM3033 Bearing, Main, 5-6HP 72.50
HM3034 Bearing, Main, 7HP 87.50
HM3035 Bearing, Main, 9HP 110.00
HM30355 Bearing, Main, 12HP 200.20
HM305 Carb, Choke Plate, 1-1/2 to 2HP 12.95
HM306 Carb, Choke Plate, 2-1/2 to 3-1/2HP 15.00
HM307 Carb, Choke Plate, 5-6HP 18.00
HM309 Carb, Needle Valve, 1-1/2 to 2HP 22.50
HM310 Carb, Needle Valve flat spring (held on with screw) 7.70
HM311 Carb, Needle Valve wire spring (goes in hole) 1.10
The Following carb parts are for kero. pump type carbs.
HM3036 Carb Drain Valve 24.00
HM308 Carb Fill Hole Lid 12.95
HM3037 Carb Fuel Needle Valve 22.50
HM3038 Carb Pump Body 100.50
HM3039 Carb Pump Plunger 37.35
HM431 Carb Throttle Water Valve Assembly 62.50
For related parts see "Fuel Line Assy", etc.
HM315 Con. Rod Bushing 1-1/2 to 2HP 14.00
HM3151 Con. Rod Bushing 2 to 2-1/2HP (3-5/8" bore) 15.50
HM316 Con. Rod Bushing 2-1/2 to 3-1/2HP 20.50
HM317 Con. Rod Bushing 5-6HP 24.00
HM3171 Con. Rod Bushing 7HP 30.00
HM318 Crankguard 1-1/2 to 2HP 62.75
HM320 Crankhandle 1-1/2 to 2HP, closed style 49.25
HM321 Decal, Economy 1-5/8" X 6" 4.00ea
HM322 Decal, Economy 3-3/4" X 10" 9.00ea
HM323 Decal, Economy "Propeller" 2-1/8" X 6-1/2" 8.25ea
HM325 Decal, Hercules Engine 7.00ea
HM327 Decal, Jaeger 8.80ea
HM329 Exhaust Rocker Lever, 1-1/2HP **Model 'N' ONLY 51.35
HM330 Exhaust Rocker Lever 1-1/2 to 2HP 34.65
HM3305 Exhaust Rocker Lever 2 to 2-1/2HP 'S' **w/3-5/8" bore 51.45
HM331 Exhaust Rocker Lever 2-1/2 to 3-1/2HP 42.35
HM332 Exhaust Rocker Lever 5-6HP 44.25
HM3325 Exhaust Rocker Lever 7-8HP 63.80
HM333 Exhaust Rocker Lever adjustment bolt (like original) 12.00
HM334 Exhaust Push Rod assy. 1-1/2 to 2HP 103.70
HM3345 Exhaust Pushrod assy. 2HP 'H', 2-1/2HP 'S' 103.70
HM335 Exhaust Push Rod only 44.30
HM336 Exhaust Cam Roller 1-1/2 to 2HP 17.05
HM3361 Exhaust Cam Roller 2-1/2 to 12HP 17.35
HM337 Exhaust Cam Roller Pin Only 1-1/2 to 2-1/2HP model 'S' 16.50
HM3371 Exhaust Cam Roller Pin Only 2-1/2 model 'E' to 12HP 11.00
HM338 Exhaust Detente Latch Block 1-1/2 to 2HP 26.95
HM3382 Exhaust Detente Latch Block 2-1/2 to 12HP 26.95
HM339 Flywheel Key, Straight, 1-1/2 to 2HP 1.40
HM3391 Flywheel Key, Straight, 2-1/2 to 2-1/2HP (3-5/8" bore) 1.40
HM3392 Flywheel Key, Straight, 2-1/2 to 3-1/2HP 1.40
HM3393 Flywheel Key, Straight, 5-6HP 1.95
HM3394 Flywheel Key, Straight, 7-8HP 1.95
HM340 Fuel line assy. (from tank to carb) 25.60
HM3405 Fuel line check valve (included with HM340) 17.50
HM3511 Fuel Line 'T' (inc. with HM340) 2.20
HM343 Fuel Tank, Fills Mag Side, 1-1/2 to 2HP 57.75
HM3435 Fuel Tank, Fills in Back, 2HP, model "H" & "?" 57.75
HM344 Fuel Tank, Fills Opposite Side, 1-1/2 to 2HP 57.75
HM345 Fuel Tank, Fills Mag Side, 2-1/2 to 3-1/2HP 60.25
HM346 Fuel Tank, Fills Opposite Side, 2-1/2 to 3-1/2HP 60.25
HM347 Fuel Tank, Fills Mag Side, 5-6HP 74.25
HM348 Fuel Tank, Fills Opposite Side, 5-6HP 74.25
HM3485 Fuel Tank, Fills Mag Side, 7-8HP 81.40
HM3486 Fuel Tank, Fills Opposite Side, 7-8HP 81.40
HM349 Fuel Tank Filler Spout w/lid, 1-1/2 to 5HP 45.40
HM350 Fuel Tank Filler Lid, 1-1/2 to 2HP 5.50
HM351 Fuel Tank Lid, Swivel 1-5/8" dia. 5.50
HM3512 Fuel Tank Lid, Swivel 2-5/8" dia. 5.50
HM352 Gasket, Cyl. Head, 1-1/2 to 2HP 9.35
HM353 Gasket, Cyl. Head, 2 to 2-1/2HP (3-5/8" bore) 9.45
HM354 Gasket, Cyl. Head, 2-1/2 to 3-1/2HP 10.45
HM355 Gasket, Cyl. Head, 5-6HP 12.65
HM356 Gasket, Cyl. Head, 7-8HP 14.85
HM357 Gasket, Mag Bracket, 1-1/2 to 2-1/2HP model 'S' 3.30
HM358 Gasket, Mag Bracket, 2-1/2 to 12HP 3.30
HM3592 Gear, Crankshaft Pinion, 2-1/2 'E' to 3-1/2HP 103.70
HM3594 Gear, Crankshaft Pinion, 5-6HP 103.70
HM3596 Gear, Crankshaft Pinion, 7-8HP 139.70
HM360 Gear, Gov. Pinion, 1-1/2 to 12HP 51.45
HM362 Gov. Detente Blade, 1-1/2 to 2HP 29.70
HM3621 Gov. Detente Blade, 2-1/2 to 12HP,(1 bolt hole) 35.50
HM3621A Gov. Detente Blade, 2-1/2 to 12HP,(2 bolt hole) 35.50
HM3621B Gov. Detente Blade Bolt, 1-1/2 to 12HP 14.05
HM3621C Gov. Detente Blade Adjusting Screw 14.05
HM3622 Gov. Detente Lever, 1-1/2 to 2HP 43.75
HM3624 Gov. Detente Lever, 2-1/2 to 12HP 43.75
HM363 Gov. Spindle Rod, 1-1/2 to 2HP 20.35
HM3632 Gov. Spindle Rod, 2HP (3-5/8" bore) 20.35
HM364 Gov. Spindle Rod, 2-1/2 to 12HP 21.20
HM3642 Gov. Spindle Shaft, 1-1/2 to 2HP 112.50
HM3645 Gov. Bracket 1-1/2 to 2HP (3-1/4" bore) 94.05
HM365 Gov. Speed Control Lever 1-1/2 to 12HP 12.50
HM366 Gov. Weight 1-1/2 to 2-1/2HP 18.45
HM3662 Gov. Weight 2-1/2 to 12HP (round style) 35.00
HM368 Gov. Weight Pin, 1-1/2 to 2-1/2HP model 'S' 1.95
HM369 Gov. Weight Pin, 2-1/2 to 12HP (early style weight) 3.30
HM371 Grease Cup, Auto, Brass, 1-1/2 to 2HP model 'S' 57.75
HM372 Grease Cup, Auto, Brass, 2-1/2 to 12HP model 'S' 72.50
GR03 Grease Cup, Rod, 1-1/2 to 2-1/2HP 8.25
GR04 Grease Cup, Main, 1-1/2 to 2-1/2HP 10.45
GR05 Grease Cup, Rod, 2-1/2 to 12HP 12.25
GR07 Grease Cup, Main, 2-1/2 to 12HP 16.50
WICO 'EK' mag linkage parts
HM374 Mag Bracket, 1-1/2 to 2-1/2HP model 'S' 63.00
HM375 Mag Bracket, 2-1/2 to 12HP 66.00
EK11 EK Trip Rocker group - contains rocker, latch block and latch block adjusting screw - (will also work with WICO PR) 35.00
EK14 Armature Return Spring, EK 4.40
EK18 Trip Finger Mag Drive Spring, EK 4.40
EK22 Armature Spring Support, EK 11.00
EK23 Armature Spring Support Shaft & Nut, EK 15.95
EK24 Trip Finger Assy., EK 71.00
EK25 Trip Finger Latch Group Only, EK 27.50
EK26 Finger Frame Group Only, EK 39.35
EK27 Trip Finger Retard Lever, EK 4.95
HM386 Trip Finger Bracket, 1-1/2 to 2-1/2HP model 'S' 42.50
HM387 Trip Finger Bracket 2-1/2 to 12HP 37.50
HM3879 Push Rod Clamp 1-1/2 to 2-1/2HP 37.35
HM388 Push Rod Clamp 2-1/2 to 12HP 43.75
For WICO 'EK' mag. parts see WICO 'EK' mag. section

Webster mag linkage parts
WEB11 Mag. Trip Finger Assy. 1-1/2 to 12HP 63.80
For Webster mag parts see Webster mag. section

HM393 Muffler, Ball, 7" dia., 1" to 1-1/2NPT (state pipe size) 58.00
HM394 Muffler, Ball, 9" dia., 2" to 2-1/2NPT (state pipe size) 120.00
HM395 Muffler, Cone, 6" dia., 1" to 1-1/4NPT (state pipe size) 58.00
These mufflers are nicely cast with square head bolts.
HM396 Nameplate, 1-1/2 to 12HP 8.80
HM3965 Piston, 1-1/2 to 2HP (3-1/4" bore), oversize available 178.75
HM397 Piston Wrist Pin, 1-1/2 to 2HP 17.90
HM3975 Piston Wrist Pin, 2 to 2-1/2HP (3-5/8" bore) 17.90
HM398 Piston Wrist Pin, 2-1/2 to 3-1/2HP 20.35
HM399 Piston Wrist Pin, 5-6HP 25.35
HM3991 Piston Wrist Pin, 7-8HP 29.45
HMR20 Piston Ring, 3-1/4" x 1/4", 1-1/2 to 2HP 6.60ea
HMR28 Piston Ring, 3 5/8" x 1/4", 2 to 2-1/2HP(3-5/8" bore) 6.60ea
HMR35 Piston Ring, 4" x 5/16" model 'E', 2-1/2HP 8.80ea
HMR39 Piston Ring, 4 1/4" x 5/16", 3 to 3-1/2HP 8.80ea
HMR48 Piston Ring, 5" x 3/8", 5-6HP 13.20ea
HMR52 Piston Ring, 5 3/4" x 3/8", 7-8HP 15.40ea
HM401 Pulley With Keyway and Set Screw, 1-1/4" shaft 91.40
Pulleys for shafts to 1-1/2
HM02 Spark plug, 1/2" NPT 5.50
HM4015 Spring, Detent, 1-1/2 to 12HP 2.75
HM402 Spring, Exh. Push Rod, 1-1/2 to 2-1/2HP model 'S' 5.25
HM403 Spring, Exh. Push Rod, 2-1/2 to 8HP 5.50
HM404 Spring, Gov. Spindle Rod, 1-1/2 to 2HP 3.85
HM405 Spring, Gov. Spindle Rod, 2-1/2 to 12HP 3.85
HM406 Spring, Exh. Valve, 1-1/2 to 2HP 5.25
HM407 Spring, Exh. Valve, 2-1/2 to 6HP 5.25
HM4075 Spring, Exh. Valve, 7-8HP 7.15
HM408 Spring, Int. Valve, 1-1/2 to 2HP 5.25
HM409 Spring, Int. Valve, 2-1/2 to 6HP 5.25
HM4095 Spring, Int. Valve, 7-8HP 7.15
HM4097 Spring, Valve Lock, 2-1/2 to 6HP 4.40
HM4097A Spring, Valve Lock, 7 to 12HP 4.40
HM415 Valve, Exh. or Int., 1-1/2 to 2HP 37.50
HM4155 Valve, Exh. or Int., 2 to 2-1/2HP (3-5/8" bore) 37.50
HM416 Valve, Exh. or Int., 2-1/2 to 3-1/2HP 41.50
HM417 Valve, Exh. or Int., 5-6HP 48.00
HM418 Valve, Exh. or Int., 7-8HP 55.0
HM4183 Valve, Exh. or Int., 9HP 62.00
HM4185 Valve, Exh. or Int., 12HP 66.00
HM4192 Valve Lock, 2-1/2 to 3-1/2HP 14.60
HM4193 Valve Lock, 5-6HP 14.60
HM4194 Valve Lock, 7-8HP 14.60
HM4195 Valve Lock, 9-10HP 14.60
HM4197 Valve Lock Stud, 2-1/2 'E' to 6HP 5.50
HM4197A Valve Lock Stud, 7 to 12HP 5.50