I’ve waited all summer long for today and “finally” the time has arrived to begin the transformation of my 2013 Harley Davidson Fatboy Lo!
The bike came factory stock with a 103 cubic inch engine. I have found that over the past 17,000 miles, mostly “two-up”, that I’d like to add some extra horsepower and torque to the bike. So this past summer, I purchased the “Harley Davidson Screamin’ Eagle Bolt-On 110 Cubic Inch Street Performance Kit”. This will bring the bike up to the same displacement and power output as the CVO Screamin’ Eagle models.
The weather has finally begun to turn cool (after a fantastic October riding month) so now is the time to begin. I’ll be posting pictures of the complete tear-down and rebuild along the way and posting comments as I go. I’ll also add an occasional video of the progress as well.
I’ll place captions in each photo with explanations , if necessary.
So the next step is to dig into the mechanical (fun) parts of the job. Up until now, it’s been just “busy work”. As you’ll see in the following photo’s, I’ll begin by removing the Rocker Box Covers. This is easily performed using a 7/16″ socket and a “Dog Bone” style extension for the bolts that are close to the backbone of the bike. I used “Snap On” tools (part #FRDH141) 2″ extension” to break the bolts free, then I used a 3/16″ Ball Hex Allen on an extended 1/4″ drive ratchet to remove them. Harley Davidson’s R&D followed by manufacturing of these particular bolts makes it easy to use multiple tools to get the job done quickly, however a quality wrench will perform the same function, be it, much slower. After removal of the covers, we’ll discard the gasket as the kit comes complete with all the essential gaskets (except the primary cover gasket, which we’ll address at a later time). Next, we removed the spark plugs with a standard 5/8″ spark plug socket.
With the Rocker Box Covers removed, I begin by turning the engine over so that the rear head push rods are setting on the camshaft base circles. This is when both valves are closed and no tension is being applied to either the intake or exhaust push rods. Because I have not yet removed the Primary Cover, I perform this step by shifting the transmission into sixth gear and with the rear wheel raised off of the lift, I rotate the rear wheel backwards. I can tell when the base circles are in the correct geometry by visually observing the movement of the valve springs and can see when both valves are fully closed. There’s another method to locate the base circles, which I’ll explain a little later on in the tear down.
Now we can release the tension on the push rod tube covers by depressing the spring cap, and using a small flat blade screwdriver inserted into the cast loop, slightly twist the retainer in a clockwise direction (for right handed folks) until the base of the retainer pops free and can be removed. Once completed, the tube covers can be collapsed but not yet removed. Now I’ll provide an alternate method of finding the cam base circles. You can still spin the rear wheel backward and periodically check the tension on the, now partially exposed push rods, by reaching below the collapsed rush rod covers and spinning the push rods themselves. If there is pressure on the rods, it will be very difficult to spin them between your fingers. Yes, it can be done, but if no tension is on the rods, they will spin freely.
With the tension off of the rods, we can begin further disassembly. First remove the Breather Baffle assembly.
Next, in quarter turn increments, remove the 4 bolts from the Rocker Arm Support Plate. Lift the Support Plate assembly off the the cylinder head as a unit. Now the push rods are removable. It is imperative that all components be tagged for function, location and orientation. This cannot be overstated! There are subtle differences between the rods and they must be returned to their original location. With the rods removed, we can now remove our collapsed rod covers. Be sure to removed the o rings (3 each: 1 yellow, 2 brown) for each tube. They may have come off the tubes and remain in the head or lifter cover plate.
Next job will be to remove the lifter covers.
Remove the four 3/16″ Allen head screws. You may find that the covers are stuck to the crank case. Patience, accompanied by many blows of a soft faced mallet will yield results. They may seem like they will not release, but in time, they will. Do not pry on the covers. This will likely mar or scratch the covers and or crank case. Trust me, they will come free with a mallet! Once free, remove the gasket which will most likely be glued to the crank case. See the figure below as the next step will be to remove the anti-roll pin. It just lies adjacent to the two lifters on their respective flat spots. Take note of the orientation of each lifter as you remove them. A magnet such as the one on the end of a pocket screwdriver, is sufficient to pull them from their bores. Note: The lifters are replaced with new parts from the upgrade kit.
The next step, one that is most important, cover these openings. Dropping items into these holes will result in a complete engine tear down in order to retrieve them. Something as simple as a rag over the top can prevent major frustration and expense because our piston wrist pin cir-clip fell through this hole. Same holds true with tools. A 1/4″ drive socket will easily fall into these bores.
Let me share a personal story with you while your here! I’ve been working actively in the Auto Repair industry for the past 12 years and I have plenty of stories I can share. I was performing a blown head gasket repair on an Isuzu Rodeo, which I had previously diagnosed. Any professional auto technician here in the states will have horror stories about working on Isuzu vehicles, and I have one I can share now too! As I am tearing down the un-kept and dirt & crud infested cylinder heads, I would occasionally stop and block off any open ports where debris could entire, then using compressed air, blow out as much crud as I could, and generally clean as I go along. Much to my surprise, the job wasn’t as bad as expected. I found my blown head gasket and proceeded to clean meticulously this nasty engine and begin the rebuild process. Cleaning coolant and engine oil out of all the orifices and ports and furthermore inspecting blind bores using a bore scope to ensure all was debris free. Just a side-bar note here: The coolant pipe (Hard-Pipe) that connects to both cylinder heads at the rear of each head is a “pain-in-the-arse” to reconnect due to extremely limited space. So frustration was building and they seemed to leak no matter my remedy. Needless to say after many, many minutes, I was successful and moved on to complete the repair.
After many hours of work, I started the vehicle and was immediately greeted with a knocking noise deep within the engine. My first thought was residual coolant in the intake runners got into the cylinder and was knocking, possibly a bent connecting rod, and that pesky knock never went away. I checked for trouble codes and misfires but found none. The vehicle ran normally minus this new knocking sound. As with every job performed, a Technician immediately performs an inventory of tools to ensure all are accounted for, and all of mine were. All hardware was accounted for and no remaining parts either. After hours of deliberation, I/we had no choice but to tear down this one cylinder bank to find the source of the knock. This meant more than just another tear down (labor) but also meant new gaskets and head bolts that are torque-to-yield! Once the cylinder head was removed, the problem was identified immediately. A Torx bit had fallen into the intake runner, past an open valve, and right onto the top of the piston. How could that be, all my tools were accounted for. I use Snap On Torx bits that are shouldered for 1/4″ drive or larger.
Here’s what happened, to the best of my knowledge. Other people had been working on this engine prior to my working on it. Someone lost a bit and didn’t bother to find it or couldn’t find it and there it stayed, until reinstalling components (from the cruddy engine) at which point, it was no longer lost, nor did I even know it was there. So the moral of the story: Just because you’re meticulous about your work, doesn’t mean other peoples carelessness won’t creep up on you. While I routinely clean my parts before reassembly, and knowing it was not in the cylinder when I installed the cylinder head, it could only have fallen into the chamber at some point AFTERWARD and I failed to catch it. That was on me (and not the customer) even though I was not directly at fault. That was lost revenue and more importantly for me, TIME!