

Kohler PA-KT745-3088 7000 Series 26 HP Vertical Shaft Engine
Replacement engine for select Bad Boy mowers originally equipped with Kohler PA-KT745-3031 / KT745-3031. Kohler PA-KT745-3088 is a 747cc, air-cooled, V-Twin, vertical shaft gasoline engine in the Kohler 7000 Series KT745 family. This engine is commonly used as the updated replacement specification for the earlier PA-KT745-3031 Bad Boy mower engine.
Important: Engine spec numbers matter. PA-KT745-3031 and PA-KT745-3088 share the same basic KT745 engine platform, but external build items such as wiring, throttle/choke controls, fuel line routing, guards, muffler hardware, and OEM brackets can vary by mower model. Always compare your original engine tag, crankshaft size, wiring plug, controls, and mounting before ordering.
Quick Fitment Summary
| Item |
PA-KT745-3031 |
PA-KT745-3088 |
| Engine Series |
Kohler 7000 Series KT745 |
Kohler 7000 Series KT745 |
| Common Application |
Bad Boy mower OEM engine |
Replacement / updated Bad Boy mower engine spec |
| Horsepower |
26 HP / 19.4 kW class |
26 HP / 19.4 kW class |
| Displacement |
747cc |
747cc |
| Engine Type |
Air-cooled V-Twin, 4-cycle gasoline |
Air-cooled V-Twin, 4-cycle gasoline |
| Crankshaft Orientation |
Vertical |
Vertical |
| Crankshaft Size |
Typically 1-1/8 in. diameter x approx. 4.3 to 4.36 in. length |
Typically 1-1/8 in. diameter x approx. 4.3 to 4.36 in. length |
| Starting |
Electric start |
Electric start |
| Main Difference |
Earlier OEM Bad Boy spec |
Later replacement / superseding spec |
What Parts Are Usually Similar?
- KT745 7000 Series V-Twin engine platform
- 747cc displacement
- 26 HP class rating
- Vertical crankshaft layout
- Electric start design
- Pressure lubrication system
- Cast iron cylinder sleeve design
- General engine footprint and mounting style
- Common service family for oil filter, air filter, spark plugs, and maintenance parts
What Parts Can Be Different?
- Wire harness plug or connector style
- Throttle and choke linkage bracket
- Smart-Choke / auto-choke related controls
- Fuel pump and fuel hose routing
- Engine shrouds, guards, and heat shields
- Muffler, exhaust shields, and mounting hardware
- Charging stator output or regulator connector
- PTO clutch spacer, bolt, or pulley hardware reused from the mower
- Emission label and carburetor calibration by production spec
Does PA-KT745-3088 Replace PA-KT745-3031?
Yes, PA-KT745-3088 is commonly listed as the replacement engine for Kohler PA-KT745-3031 / KT745-3031 Bad Boy mower applications. In most repower jobs, the long block and major engine layout are the same or extremely similar. The installer may still need to transfer some external parts from the original engine to make the mower controls, exhaust, wiring, or PTO clutch match correctly.
Before You Order — Please Verify These Items
- Original engine model and spec number from your Kohler engine tag
- Crankshaft diameter and length
- Crankshaft bolt thread and keyway
- Vertical shaft orientation
- Wiring plug style and charging connector
- Throttle/choke cable arrangement
- Muffler and exhaust shield requirements
- PTO clutch and pulley hardware
- Deck belt alignment after installation
Important Installation Notes
Does not include the muffler system unless specifically stated. Many replacement engines are shipped as the engine assembly only. Mufflers, exhaust shields, mounting brackets, spacers, pulleys, PTO clutch hardware, and mower-specific parts may need to be reused from the original engine.
Professional installation is recommended. Always disconnect the battery, compare the old and new engine side by side before final installation, and test all safety switches, charging output, throttle response, choke operation, and PTO engagement before returning the mower to service.
Corrected Specifications
| Brand |
Kohler |
| Model / Spec |
PA-KT745-3088 |
| Engine Series |
Kohler 7000 Series KT745 |
| Engine Type |
Air-cooled V-Twin, 4-cycle gasoline |
| Crankshaft Orientation |
Vertical |
| Crankshaft Diameter |
1.125 in. / 1-1/8 in. |
| Crankshaft Length |
Approx. 4.3 in. to 4.36 in. |
| Displacement |
747cc |
| Power Output |
26 HP class |
| Start Type |
Electric start |
| Common Replacement For |
PA-KT745-3031, KT745-3031, PA-KT745-3088, and select Bad Boy mower applications |
| California Sales |
Verify current emissions eligibility before shipment |
Common Cross Reference / Search Terms
PA-KT745-3088, PAKT7453088, KT745-3088, PA-KT745-3031, PAKT7453031, KT745-3031, Kohler 7000 Series 26 HP, Kohler 747cc V-Twin, Bad Boy mower engine, Kohler vertical shaft engine, 1-1/8 inch crankshaft engine.
Frequently Asked Questions
Question: Is PA-KT745-3088 the same as PA-KT745-3031?
Answer: They are not always identical in every external attachment, but they are the same KT745 7000 Series 26 HP engine family. PA-KT745-3088 is commonly used as the replacement or updated build for PA-KT745-3031 Bad Boy mower engines.
Question: Will I need to reuse parts from my old engine?
Answer: Possibly. It is common to reuse the muffler, heat shields, wiring adapter, throttle/choke brackets, PTO clutch hardware, spacers, pulley parts, or mower-specific mounting hardware.
Question: Does this include the muffler?
Answer: No, unless the listing specifically states otherwise. Assume the muffler system is not included.
Question: Why do Kohler spec numbers matter?
Answer: The KT745 model identifies the engine family. The final spec number, such as 3031 or 3088, identifies the OEM build configuration. That can affect external controls, wiring, fuel routing, emissions calibration, and equipment-specific hardware.
Question: What should I check before ordering?
Answer: Match the engine tag, crankshaft size, shaft orientation, wiring, throttle/choke setup, mounting, muffler configuration, and PTO clutch arrangement. When in doubt, send photos of your engine tag, crankshaft, wiring plug, and mower model before ordering.
Pictures

Cross Reference Skus
PA-KT730-3061
PA-KT740-3049
PA-KT730-3025
PA-KT740-3045
PA-KT735-3091
PA-KT715-3060
PA-KT725-3104
PA-KT745-3090
PA-KT740-3041
PA-KT745-3060
PA-KT745-3098
PA-KT745-3097
PA-KT745-3042
PA-KT745-3058
PA-KT745-3087
PA-KT730-3041
PA-KT730-3062
PA-KT745-3092
PA-KT745-3088
PA-KT745-3089
PA-KT745-3031
PA-KT745-3001
PS-SV840-3018
PA-KT745-3008
Documenation
Owners Manual
Service Manual |
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