Part I: Spark Plug Basics

Maintenance and Set Up Tips

Replacing of plugs really should be almost as easy as changing light bulbs, however it's not. Bulb replacement does not involve the use of a socket wrench or gapping utilities. A deep socket that fits a plug isn't a suitable spark plug socket. A plug socket has a couple of things that separate it from a deep socket.

The first is a foam rubber insert that pads the spark plug while it is in the socket. Second is the hexagonal part around the top socket. The hexagonal area provides the wrench to set on the socket if there is insufficient space for the ratchet. Motorcycles usually have plenty of space for ratchets and torque wrenches, but the ability to accommodate a wrench on the socket comes in handy for motorcycles with Fat Bob tanks as well as some automotive applications (like a Corvette with headers).

For several years there have been two standard types of plug sockets. 80" Big Twin Evolution and Shovelhead engines require a 3/4" spark plug socket, and Evo Sportsters and Twin Cams need a 5/8" one. And then something took place: spark plugs that required an 11/16" socket came out on the shelves, and 11/16” spark plug sockets are sometimes hard to find. I've seen people fit a short length of foam pipe wrap (the one used commonly in hot water pipes) inside of an 11/16” deep socket to make their own. This procedure is effective and is also an inexpensive solution to improvise an instrument for the person who doesn't replace a lot of 11/16” spark plugs.

Plug Spacing

Spark plug spacing is crucial for accurate firing. Many people assume plugs are already gapped from the factory, which isn't usually correct. Though even if plugs are already gapped, movement when shipped may make the spacing quite a few thousandths inches shorter. Spacing a spark plug isn't rocket science. All it takes are the appropriate tools, some practice, and a little bit of determination.

For starters, pliers and a feeler gauge are not the right tools. Our preferred gapper is the simple, good-old wire-loop tool where every wire loop stands for a distinct size of the gap, and also the metal tabs support a variety of ground electrodes. Our very least favorite may be the disc which has the ramp around the perimeter. The first issue with the disc style is that it puts strain on the center electrode while gapping. Another problem is that one part of the ground electrode might end up somewhat farther out from the center electrode. Screamin' Edge and SplitFire spark plugs, one prong of the ground electrode can be higher than other plugs.

Focusing on 3 straightforward procedures will allow you to correctly gap plugs. Initially, don't try to bend the center electrode. Second, never bend the ground electrode laterally. Utilize the spacing tool to slowly push the tip of the ground electrode near or farther from the tip of the center electrode. Additionally, check the gap by working out the correct wire loop in between the gap. The spacing is right when you feel a slight amount of friction when the wire moves in the gap.

Changing Spark Plugs

Just before the removal of a plug, wait until the engine has cooled down, and then start using a shot of compressed air to clear out dust and dirt away from the space around the spark plug. A ratchet and a spark plug socket are my desired utilities for this section of the process. Upon cautiously taking off the spark plug wire by pulling on the boot, not the wire, I remove the aged plug with a ratchet and plug socket by turning them counter-clockwise.

When the worn out plugs are finally out, it is time to mount the correctly spaced plugs. Start out by putting a tiny amount of lubricant on the threads for each plug. Current Harleys have aluminum heads and spark plugs have a steel shell. Repeated heating and cooling of the cylinder heads may cause a chemical reaction from the steel spark plug shell and the aluminum cylinder head. This results in an effect like it has been welded.

Soon after applying the lubricant oil around the spark plug threads, begin winding the spark plug clockwise into the head working it with your fingers rather than a ratchet and plug socket. A best practice that lowers the possibility of getting a cross threaded plug and the costly damages that may occur.
After the brand new spark plug is finger-tight, reach for the torque wrench and spark plug socket. The torque spec for spark plugs in a TC 88 is 11-18 ft-lbs., so split the difference and go for 15 ft-lbs.

By doing this, if the torque wrench turns out to be off with no reason in mind, you will still be within the recommended spec. Is the right torque critical for spark plug installation? Typically, indeed yes! If the spark plug is too loose, heat exchange to the head may be reduced, while the plug may overheat. If a spark plug remains not tight enough, it possibly can work its way out from the head due to vibration and combustion pressure. And that is very harmful. Insufficiently tightened spark plugs are also held responsible for combustion chamber debris finding their way into the threads of the spark plug hole.

On the other part, turning plugs too tight can cause other problems. If a spark plug is tightened too much, the chances are it'll be harder to take out. Over tightening may also crush the gasket on the gasket seat plug. Over tightening can harm the threads in the head and has been the suspect in the gap distorting.

Without having a torque wrench, get the fresh plug tightened using the finger and utilize a ratchet to carefully tighten the plug another quarter to half a turn. This approach is certainly a lot less accurate as compared to utilizing a torque wrench, but it can get you somewhere in the 11-18 ft-lbs. limit.

This season, bike runs are going to kick off all throughout the US. The vast majority of motorcyclists will undoubtedly be congregate for one week long festivity all expressing their love for bikes. You will hear a number of stories and building tips to chat about with brand new friends while you ride the time in the rally. Be sure to ride safe and put on the necessary safety equipment like carbon fiber helmets. Best of luck and have a wonderful ride.

An Easy Method to Fine-tune A Primary Chain

The design of a Big Twin's Powertrain is non-unitized. Specifically, the gear box is mounted apart from the engine, meaning the two should work side by side in order to pass power. This is where the primary drive, inside that huge aluminum case next to the biker's left boot, takes into action.

From the name itself, the main drive passes power from your engine to, ultimately, the backend wheel. The reciprocating power that’s provided by the engine’s crankshaft is transformed into rotating power through the running major chain and sprockets that spin the transmission’s input shaft. Once the energy regroups within the transmission it’s spread from the gears and into the supplementary drive, which is the chain or belt drive that turns the bike's rear end tire. This is a brief description of a Harley powertrain, and, basically, each part takes on an integral part in moving you and the bike around the highway.

Being that the powertrain is made up of a group of moving components, you’re going to have to carry out regular adjustments to them so they will work properly. In time, moving parts, just like the main drive’s sprockets and chain, degrade. As things wear, they need adjustment to help maintain correct tolerance. And it’s the main driver’s multi-row roller chain that must be looked over and fine-tuned once in a while. It’s a fairly easy procedure, at the same time, a method that you can do in your own garage or shop.

Many of the action comes about around the inspection window that is reached by taking out the plate secured on by four screws. You will need to have a ruler to make the sizing and a set of essential tools to perform the adjustments. To adjust, release the adjusting shoe’s 9/16” bolt a few turns and rotate the shoe upwards to tighten the chain or downwards to loosen.

A good time to examine and adjust the main chain takes place when you have to drain and replace the primary case oil. Harley Davidson suggests its versatile synthetic oil, however, if you already have a desired brand that’s been produced for the primary drive, by all means, use it. Just make sure no matter what oil you decide is designed for this function.

When you have removed the inspection plate, you've got a good view of the chain’s components related to it, so makes use of the time to check them for wear. Look at the chain’s rollers to find out if they are receiving total lubrication, and check the adjuster shoe for breaks and such. Inspecting and fine-tuning the main chain is quick and easy, when you’re finished you can have one thing of the checklist of things to do on your next drive. Remember to replace the inspection plate gasket.

Things You'll Need:

Pipe sealant
Drain pan
T27 Torx
T40 Torx
9/16” deep socket
Ratchet
Ratchet extension
Ruler

1. Basic care such as fine-tuning the primary chain can be executed in your own garage or shop when it’s time to change the primary oil. Be sure the motorcycle is fixed in an upright stance once you begin.

2. The first thing to do is usually to drain the main case of its used fluid. After placing a drain pan beneath the primary, work with a T40 Torx to take out the drain plug which is positioned just beneath the derby cover.

3. Leave the used primary fluid to drain into the pan. While it drains, you can easily inspect the main chain to find out if it needs tuning.

4. Use a T27 Torx socket to get rid of the 4 bolts that hold the primary inspection plate in position. It’s smart to change the inspection plate gasket before you install the plate.

5. While the inspection plate is removed, you can examine the chain’s rollers for signs of wear. Try inspecting them for hints of damage. With the transmission in neutral, spin the engine a little bit several times so you can see the whole chain.

6. While checking several places in measuring the chain, always note doen two readings. First is with the chain’s top run at slack. Second, the ruler is raised from the top run to remove the slack and to measure once again. The main difference within the 2 at the chain’s tightest point is definitely the chain’s slack.

7. Work with a 9/16” deep socket to fine tune the chain’s free play. With the chain cold, fix the free play between ½” and 7/8”. After you have tightened the nut again, measure the slack again to ensure that you have established the proper amount.

8. Since the inspection plate is open, additionally check out the adjuster shoe that is pushing against the chain’s under run. On the upper right corner, you'll find the adjustment nut.

9. Not like the motor and transmission drain plugs, there’s no O-ring on the primary case drain plug. To aid in sealing it, rub a little pipe sealant along the base of the bolt.

10. Soon after you're done clearing off the oil from the main cover, re-install the main case drain plug. When already set, carefully twist the inspection plate's bolts as well as the derby cover bolts to 108 in-lbs.

11. You can now fill up the primary case with clean fluid. Many mechanics use lubes from the big barrel rather than retailed canisters.

12. Fill in 32 oz . of fluid. Add the right amount for your year and model bike.

This year, bike runs are set to kick off from various states. A multitude of bikers will be congregating for one week of celebration all expressing their fascination with motorcycles. There will be a lot of stories and building tricks to recommend with brand new mates while you ride the days the time in
while in the bike runs. Ensure that you drive safe and slip on the necessary safety equipment like carbon fiber helmets. Good luck and have a fantastic run.