1 The removal of stuck, stripped or broken fasteners does not need to end in tragedy. There are procedures you can follow to attack this problem. Let's start with some preventive measures. Before attempting to remove fasteners with known corrosion problems, squirt a penetrant oil, such as WD-40 or liquid wrench, and allow it to sit overnight. Fasteners known to have permanent locking agents, such as Loctite, will require heat to get them out. Brake rotor bolts are the most commonly ruined fasteners due to locking agents.
2 If the fastener in question is too tight and you haven't ruined the head of the fastener yet, a hand-held impact driver would be the first tool to try. Take the impact driver's bit and tap it into the head of the fastener, attaining the tightest fit possible. Attach the impact driver to the bit, applying turning pressure counterclockwise, and strike it firmly with a hammer.
3 Should the fastener not come loose with the impact driver, attempt to remove it with a pair of channel locks, which also may be used at any other time during the removal process should any part of the fastener become exposed.
Using a hammer and centerpunch (or dull chisel method) is the last option before drilling becomes necessary. Take the hammer and centerpunch and put a dimple in the side of the fastener's head. Place the tip of the centerpunch into the dimple, angling the punch so that when struck by the hammer it will turn the fastener in a counterclockwise direction. If repeated attempts fail to loosen the fastener, it will have to be drilled.
4 If you need to drill, the most important thing to accomplish is a centered and straight hole. A little extra time spent here will prevent further disaster. With that in mind, take the centerpunch and put a mark in the center of the fastener's head. Then take a small drill bit and make a "pilot" hole straight down the center of the fastener to help guide the bigger drill bit that will follow. A right-hand drill bit will work fine to drill the head off of the fastener should that be indicated, but a left-hand drill is preferred to drill down through the bolt. A left-hand drill bit necessitates a reversible drill set in the counterclockwise direction. More often than not, the left-hand drill bit will bite, grabbing the fastener and twisting it right out. Work slowly and patiently with the drill bit, keeping it thoroughly lubricated to avoid breaking it off in the fastener.
5 Should the fastener not back out with the use of the left-hand bit, a screw extractor can be used to complete the removal. Take the proper-sized bit supplied in the screw extractor kit and hammer it into the center of the drilled fastener. Once the bit is set in the hole, slide the fitting used to spin the bit onto the bit. While stabilizing the top of the bit with one hand, use a wrench to turn the fitting and remove the fastener.
Should this method fail, or a hardened drill bit or extractor bit break off in the fastener, removal can only be completed with the use of an EDM machine. This very special machine electrically burns out the broken fastener/bit. This method is expensive; average cost for one fastener/bit to be removed is around $50.
6 Once the fastener is removed, more often than not, the threads it came out of have been compromised. If this is the case, a thread-repair insert will need to be installed. There are a few variations of inserts available-Heli-coil and Timesert are commonly used types. These products come in a kit that includes a drill bit, special tap, insert driver, and a supply of inserts.
7 To begin the installation, clean the affected hole and drill it with the kit-specified drill bit. Clean out the hole again and proceed to tap the hole (a tap cuts thread) with the special tap supplied, using grease on the tap to capture metal flakes. After the hole is tapped, thoroughly clean it and coat the new threads with Loctite. Now install the insert onto the insert driver, and proceed to wind it into the prepared hole.
8 Once the insert bottoms out, remove the driver by spinning it back out. If any threads are still exposed, trim them with diagonal pliers or a Dremel-type grinder. Then, using a hammer and punch, break off the drive tang on the bottom of the insert and remove it, and check the repair with a new fastener. If the repair is successful, reinstall the part, and go for a well-deserved ride.
How and why
Most bikes come with a tool kit that has all the tools needed to remove the bodywork and extract the spark plugs. The owner's manual will also be helpful as it can provide details on this operation. A supply of compressed air, gauges, and a pencil and paper are all that is necessary to perform these tests.
A running compression gauge kit can probably be found at most auto parts stores. We use the Blue Point compression gauge, available through Snap-on. The part number is MT308KB and the kit retails for $149.95.
We think the leakdown tester we use is of the best quality for the money. It is available through Uyematsu Tools (818/410-9428) as part number SRAT1006 and retails for $99.95. A leakdown tester is also available through Snap-on. Its part number is MT324 and it retails for $214.95. Finally, performance companies such as APE (818/842-4952) carry complete gauge kits-the one shown (right) sells for $114.76 with attachment hoses.
This article was originally published in the December 1996 issue of Sport Rider.
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