Cylinder 2 Misfire Detected on V-Twin
The KAWASAKI-FX-P0302 (Kawasaki FX / FR / FS) diesel fault code means: Cylinder 2 Misfire Detected on V-Twin. This is a serious severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- moderate
- Estimated cost
- DIY: $5-$80 for spark plug, plug wire, or ignition coil. Pro shop: $80-$350 depending on whether the fix is a plug and coil swap or a compression-related repair requiring internal engine work.
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Common Symptoms
- Engine runs rough or surges noticeably at idle and under load
- Noticeable vibration through the deck, seat, or handlebars more than usual
- Engine power feels reduced, especially on hills or thick grass
- Fuel consumption increases without a change in workload
- Engine may pop, backfire, or stumble when throttle is applied
- Check engine light or fault LED blinks on EFI-equipped mowers
- Engine occasionally hesitates or nearly stalls when engaging the PTO
Probable Causes (Ranked by Likelihood)
- Fouled, worn, or incorrectly gapped spark plug on cylinder 2 Very Likely
- Failing or cracked ignition coil on the cylinder 2 side Very Likely
- Dirty or clogged fuel injector on cylinder 2 (EFI models only) Likely
- Low compression on cylinder 2 due to worn rings, valve wear, or valve seating issues Likely
- Damaged or corroded spark plug wire or boot allowing spark to arc to ground Possible
- Intake air leak at the carburetor base or intake manifold gasket on the cylinder 2 side Possible
- ECU or wiring harness fault causing incorrect fuel or ignition signal to cylinder 2 Less Likely
Step-by-Step Diagnostic Procedure
Start by identifying which cylinder is cylinder 2 on your engine. On Kawasaki V-twins, cylinder 2 is typically the rear cylinder closest to the operator when seated.
Remove the spark plug from cylinder 2 and inspect it. Look for heavy carbon fouling, cracked porcelain, erosion on the electrode, or oil fouling. The plug gap should be 0.028-0.031 inches (0.7-0.8mm) per Kawasaki spec. Replace the plug if in any doubt, they are cheap and this is the first fix to try.
Swap the ignition coil from cylinder 1 to cylinder 2 and clear the fault code using the Kawasaki diagnostic tool (KDS) on EFI models, or disconnect the battery for 30 seconds. If the misfire moves to cylinder 1 (P0301), the coil is confirmed bad. Coil air gap spec is 0.010-0.014 inches (0.25-0.35mm). Check the gap with a feeler gauge before condemning the coil.
Inspect the spark plug wire and boot on cylinder 2 for cracks, carbon tracking, or a loose connection at the coil. Pull the boot and look inside for corrosion or burn marks. A damaged boot can cause intermittent misfires that get worse in wet conditions.
On EFI models, use the Kawasaki diagnostic tool (KDS) to check live fuel injector data for cylinder 2. If injector pulse width looks correct but misfire persists, try an injector cleaning or swap injectors between cylinders and see if the misfire follows.
Perform a compression test on cylinder 2. Kawasaki FX series spec is typically 150-200 PSI with a minimum of 128 PSI. If cylinder 2 reads more than 10% lower than cylinder 1, or below spec, you have a mechanical issue. Add a small amount of oil through the plug hole and retest. If compression rises, rings are worn. If it stays low, suspect a valve problem.
Check for intake air leaks on the cylinder 2 carburetor throat or intake manifold base gasket. With the engine running rough, spray a small amount of carb cleaner around the intake boot and gasket area. If the engine RPM changes, you have found a vacuum leak. Do not spray near hot exhaust.
If all the above checks pass, the fault likely points to a wiring harness issue or ECU problem. At this point, bring the mower to a dealer with a Kawasaki diagnostic tool (KDS) for deeper testing. Wiring faults require pin-by-pin continuity checks that go beyond basic tools.
Frequently Asked Questions
What does Kawasaki code P0302 mean on my commercial mower?
P0302 means the ECU detected that cylinder 2 on your V-twin is not firing correctly or consistently. On Kawasaki EFI engines, the ECU tracks crankshaft speed variations between power strokes. When cylinder 2 skips, the crank slows slightly during that stroke, and the ECU logs the misfire. This code tells you the problem is specific to cylinder 2, which narrows down your diagnosis considerably.
Can I keep mowing with a P0302 misfire code?
You can run the mower in a limited capacity, but it is not a good idea to keep pushing it. Running on one weak cylinder puts extra heat and load on the good cylinder, can damage the catalytic converter on compliant models, and will likely cause the misfire to get worse. Get it diagnosed before your next full day of work.
How much does it cost to fix a P0302 on a Kawasaki FX engine?
If it is just a spark plug, you are looking at $5-$15 in parts and 15 minutes of your time. A new ignition coil runs $40-$80 in parts. If the engine has low compression on cylinder 2 from worn rings or a bad valve, a shop repair can run $250-$600 or more depending on what they find inside. Start with the cheap stuff first.
Will my mower start and run with a P0302 code active?
Yes, the mower will usually start and run. It will just run rough, feel underpowered, and vibrate more than normal. The code does not shut the engine down on most mower applications. However, if the misfire is severe enough to cause hard starting, that usually means a compression problem or a completely dead ignition coil, not just a bad plug.