The better, safer ways are these:
1. Use a manual impact tool, sold in most auto parts stores. See 5-79 in Chapter 5. Unlike the professional impact tool powered by electricity or by compressed air, this one is whacked with a hammer and it shocks the
nut, bolt or screw loose better than the ratchet and hammer setup in 6-7.
The tool has many household and automotive uses. Suggestion: To prevent possible damage to the piston, remove the spark plug, turn the flywheel until the piston is down, and thread clothesline through the spark plug hole into the cylinder to serve as a shock absorber.
2. Get a flywheel holder from the parts distributor. As shown in 5-62 in Chapter 5, it allows you to restrain the flywheel by grabbing both ends of two fins. Although limited in scope, it’s cheaper than the manual impact tool ($3 to $6 versus about $12).
3. Try to jerry-rig something that will hold the flywheel without dam aging it. If the flywheel is small enough and the nut isn’t impossibly tight, an automotive oil filter wrench might fit around and hold it. A chain vise type plier wrench also might work. Either might require you to remove the magneto coil to get the wrench all the way around. So if you do, be sure to scribe alignment marks on the magneto and engine with touchup paint, nail polish or the like. See 6-10.
On most Briggs and Stratton engines, there is no flywheel nut. A special clutch assembly for the starter has a threaded hub that performs the same function. There are special tools that hold the flywheel and enable you to loosen the hub, but a soft flat-end punch or drift whacked against the cllltch ears with a hamlner nsl~ally will do the jol, as well; see ii-62 and 63 in Chapter 5. If the Briggs engine has a nut, see 6-l 1.
On all but the Briggs setup and many chain saws, the next step is to shock the flywheel loose from its tight fit the tapered part of the wheel. Most professional shops use a special closed-end nut and a hammel . They thread the nut onto the flywheel, until it is finger tight, and then whack the closed-end top with a hammer, while prying from under neath the flywheel with a screwdriver or two.
The closed-end long nut is called a shock nut, and although it’s not expensive and is reasonably available, you can achieve the same effect by just loosening the flywheel nut and threading a second nut onto the flywheel, so that the second nut projects above the end of the flywheel. With wrenches, lock the two together, and you’ve got the equivalent of a shock nut.
Many chain saws do not have the heavily tapered flywheel end, so that once the nut is off, gently plying with a pair of screwdrivers will lift the flywheel up and off.
If you’re lucky, somewhat more than gentle prying with screwdrivers will the Briggs flywheel; see 5-66 in Chapter 5. If this doesn’t work, you probably won’t be able to use the shock nut system because the end of
the typical Briggs flywheel isn’t threaded. Briggs does make special pullers (6-13 through 6-14) to cover the situation. Tecumseh also has one ((j-15), but the Tecmnseh’s shock nut works every bit as well.
Although Briggs and most chain saw engines have flywheel retention devices that differ from the usual in small gas engines, all engines have fly wheel keys. So the key deserves your special attention.
