The flywheel on your small engine holds the momentum created by combustion in order to keep the crankshaft spinning between power strokes. By dispersing air around the engine block, the fins help cool. The fins also blast air across a pneumatic governor’s air vane, ensuring that the engine speed remains constant.
Finally, if a lawn mower or tiller blade collides with a rock or curb, the flywheel key may absorb the damage, considerably lowering replacement expenses. Always inspect the key and the keyway, which is the key’s slot on the crankshaft, for damage by removing the flywheel. The soft metal key removes any play between the flywheel and the crankshaft.
A flywheel key could be simple to remove, yet as with any engine, and not only Briggs & Stratton lawnmowers, the flywheel can be hard to remove. To do so, the use of a flywheel puller is needed.
In our guide, you can learn the Briggs and Stratton flywheel puller bolt size. By the end, you’ll also find a guide how to remove the flywheel from your mower. (Read Briggs And Stratton Oil Capacity Chart)
What Size Bolt Is On A Briggs and Stratton Flywheel?
Briggs & Stratton small engines, are found in lawnmowers, rototillers, and snow blowers. Each model can use a flywheel-based ignition method.
Magnets on the flywheel’s side spin past the ignition coil, telling the coil to ignite the engine by sending an electrical charge to the spark plug.
If the engine flywheel is broken and needs to be replaced, as well as if you need to access the ignition parts and components, it must be removed.
A simple socket wrench set will suffice for the most of the job, but a specialized flywheel pull tool will be required regardless of model. (Read Briggs And Stratton Engine Starts But Won’t Stay Running)
Briggs and Stratton Flywheel Nut Size
|Brand||Briggs & Stratton|
|Item Dimensions L x W x H||1 x 7 x 8 inches|
|Briggs & Stratton 690662 Nut Replaces 94877, 92284, 555038, 690662|
- To prevent the engine from starting accidently while working, twist the boot off the spark plug by hand. This is a spark plug cover made of rubber that fits over the spark plug.
- To gain access to the engine flywheel, unscrew the 7/16-inch engine air shroud retaining bolts with a 7/16-inch socket wrench. (five bolts)
- 3. Using a 1/2-inch socket wrench, unscrew the 1/2-inch fuel tank retaining bolt that attaches the fuel tank to the engine air shroud.
- Between the fuel tank and the engine crankcase, the engine air shroud will slip.
- Using a 1/4-inch socket wrench, unscrew the 1/4-inch oil filling tube retaining bolt.
- If you have one, remove the flywheel brake cover screws using a Phillips screwdriver.
- With needle-nosed pliers, remove the outer end of the flywheel brake spring from the flywheel brake bracket.
- While removing the flywheel clutch, wrap a flywheel strap wrench around the outside of the flywheel to keep it steady.
- Using a flywheel clutch tool, unscrew the flywheel clutch from the engine crankshaft on top of the flywheel. Some Briggs engines include a flywheel clutch, whereas others only have a cup and retaining nut to keep the flywheel in place.
- To keep the flywheel from sliding, unscrew the flywheel retaining nut with a socket wrench while gripping the flywheel with a strap wrench.
- Remove the metal cup from the crankshaft of the engine. To preserve the threads when using a flywheel removal tool, thread the flywheel retention nut onto the last few crankshaft threads by hand.
- Place the flywheel puller tool on top of the crankshaft and slide the flywheel puller’s center hole over the crankshaft’s end. The crankshaft retaining nut is where the flywheel puller tool rests.
- On each side of the crankshaft, find the two holes on top of the flywheel that are directly in line with each other.
- Match the holes in the flywheel puller tool to the holes on the flywheel’s top. Insert a bolt into each of the flywheel puller tool’s holes. Screw the bolts into the holes on each side of the crankshaft on the top of the flywheel.
- To separate the flywheel from the crankshaft, uniformly tighten the two flywheel puller tool bolts with a wrench.
- Once the bolts are tightened sufficiently, the flywheel will pop up. As you tighten the nuts, the flywheel puller tool lifts the flywheel in a pulling motion from the engine crankshaft.
More Flywheel Removal Tips
Do flywheel bolts have reverse thread?
The thread on the flywheel bolt/nut is standard (right tight, left loose). So, anything that prevents the flywheel from turning will suffice.
How should I remove the flywheel on a Briggs and Stratton engine?
Some Briggs engines include a flywheel clutch holding the flywheel in position. Others only have a cup and retaining nut to keep the flywheel in place. To keep the flywheel from sliding, unscrew the flywheel retaining nut with a socket wrench while gripping the flywheel with a strap wrench. (Read our Briggs And Stratton Snow Blower Reviews)
How can I remove the flywheel from the crankshaft?
Grab the flywheel strap wrench tightly and alternately but equally tighten the flywheel puller bolts with a socket wrench to remove the flywheel from the crankshaft.
After the bolts are evenly tightened, the flywheel will pop free from the crankshaft. With the flywheel strap wrench removed, lift the flywheel off the crankshaft.