5 Problems With Kawasaki FR691V Engines and How To Fix

A powerful lawn mower translates to efficiency when working in your yard. The mower will run smoothly, giving you impressive results. You need a robust engine for your mower to have such incredible qualities.

The Kawasaki FR691V mower engine is a considerable selection if you target effortless operation. The engine’s specs, including a 23-hp rating and 39.3 ft-lbs torque, are pretty impressive. While it is the perfect accessory for your mower, you should be ready for Kawasaki FR691V issues. The leading Kawasaki FR691V problems are overheating, a dirty carburetor, backfire, stalling, and weird noises.

Read on to know what may plague your FR691V and possible fixes.


An overheating mower engine is a recurrent problem that you have probably encountered. It is a frustrating issue that can affect your workflow as the engine may stall. You know you have this problem when the engine gets too hot or produces black smoke.

The following are some causes of a heated-up FR691V Kawasaki engine.

  • Blocked air vents
  • A blunt, bent, imbalanced, or loose blade
  • Low cutting height
  • A clogged deck 
  • Lubrication issues

The Fix

Troubleshooting an overheating engine calls for inspecting the deck and blades to see if they are functional. Clean the deck to remove any debris that may stress the engine. Next, sharpen and balance blunt and imbalanced cutters. Adjust the cutting height to a usable level for smooth operation and precise cuts.

Check the air vent, clean it if it is dirty, and replace it if broken. For lubrication issues, you must ensure that you have sufficient oil and that the Kawasaki FR691V oil filter is in working order. Replace the filter if it is faulty.

A Dirty Carburetor

The carburetor is a crucial part of the mower engine that mixes fuel and air. A dirty carburetor is a common complication of the FR 691V. You know your carburetor needs cleaning when the engine has trouble starting, a rough operation, sudden stalling, production of black smoke, and poor fuel consumption. 

The Fix

Regular cleaning is the answer to a dirty carburetor. You have to remove it from the engine assembly. Ensure the engine is not running before unmounting the carb and disassembling it. Use a dedicated carburetor cleaner or WD-40 to remove the gunk. Also, remove rust with sandpaper. 

Let the engine part dry before you assemble and mount it back. You should also check components like the gaskets and diaphragm and replace them if necessary. Get a new carburetor if it performs poorly after cleaning. 


The FR691V Kawasaki may backfire under load due to the air and fuel mixture combusting outside the cylinders. The backfire results in a sudden, startling bang. You may notice this issue when you go uphill or mow rugged surfaces. The problem subsides when the blades stop running.

Backfiring may occur at different times: when starting the engine, running, or shutting it off. You should note the times it backfires for easy diagnosis of the problem. 

Backfiring when starting the mower indicates that you have a damaged flywheel. If you encounter this problem when the mower runs, the carburetor may be the cause. Carb adjustment issues lead to running rich or lean. Running rich means the carb is delivering too much gasoline, while running lean is the delivery of excess air.

After-firing or backfiring when shutting the engine occurs due to fast deceleration. 

The Fix

Start by getting to the root of the complication. Replace damaged flywheels and adjust the carburetor to prevent them from running rich or lean. Gradually reduce the mower’s speed and leave it on idle for roughly 30 seconds before turning it off. This prevents after-firing. 

In case of a damaged carb, you need to get a new one or make the necessary fixes. Address any overheating problem, as it is one of the causes of backfiring.


The Kawasaki FR691V engine may stall on the field or after you start it. The primary suspect behind this trouble is a faulty fuel line due to a malfunctioning fuel pump, a clog, and low or poor-quality fuel. Overheating and a bad carburetor are other causes of a stalled engine.

The Fix

You deal with a stalled engine by ensuring you have adequate fuel in the tank. The fuel should be high-quality, as recommended by the equipment manufacturer. A fuel tank flush is handy if you use the wrong, low-grade, or contaminated fuel. Probe the fuel line to clear doubts of a clog. A vacuum pump can help unclog a fuel line. 

Additionally, inspect the fuel pump, and make the necessary repairs or replacements. Sort out overheating and a bad carburetor to bid goodbye to a stalled engine.

Strange Engine Noises

While engine noises are common due to the moving motor, some may be abnormal and point to an underlying complication. Clicking, popping, and grinding noises are among the sounds to be keen with to avoid more problems. 

The noises may come from the deck and blades, overheating, and faulty engine parts. Let us look at how to solve this Kawasaki FR691V problem.

The Fix

You should try and locate the noise source and its nature for easy diagnosis. Clicking is mainly due to a weak battery, a faulty starter, a broken flywheel, or blades hitting a foreign object. Clean the battery’s terminals, or get a new battery if the issue recurs. Replacement is the best solution for a bad starter and broken flywheel.

Scan the deck and blades to see if everything is okay. Bent blades and debris in the deck can produce a racket. Grinding sounds are a sign of poor lubrication. Inspect the bearings and oil to restore the equipment’s functionality.

Closing Remark

The Kawasaki FR691V is an excellent addition to your mower. This motor is powerful and will serve you decently if properly maintained. However, the FR691V is prone to overheat, a dirty carburetor, strange noises, stalls, and backfires. Stay ahead of the complications via regular maintenance and inspections.

Frequently Asked Questions

How good is the Kawasaki FR691V?

The FR691V is the go-to engine to boost your mower’s power and efficiency. With a power rating of 23 horsepower and 39.3 ft-lbs, this motor is potent and suitable for heavy-duty lawn mowing.

Why does my lawn mower engine suddenly stop after I turn it on?

Your mower engine may stall when you start it due to a dirty carburetor, insufficient or poor-quality fuel, or defective plugs. Troubleshoot the motor to prevent a repeat of this hiccup.

What is the displacement of the FR691V?

The Kawasaki FR691V is a 2-cylinder engine with a 726-cc displacement.

Why is my lawn mower consuming a lot of fuel?

Your mower’s hiked fuel consumption may be due to using wrong or low-grade fuel, dull or imbalanced blades, and carburetor issues. Make the necessary tunings to prevent excess fuel consumption.