Motorcycle ¨ Automotive ¨ Aircraft
4059 Highway 99 W, Orland, CA  95963 ¨ Ph. (530 865 7010 ¨ Fax (530) 865 7875

Twin Cam Instructions

Although relatively simple, these instructions require strict attention to detail when installing the blower in order to prevent serious damage to the blower, the engine, or both.  This procedure assumes the individual doing the installation has access to the tools normally associated with Harley Davidson Motorcycles, and has a working knowledge of the V-Twin engine. If you are uncomfortable with disassembly or reassembly of the Harley Davidson Twin Cam engine, you should not attempt this procedure and instead, contact your local Harley Davidson dealer for recommendations on where to have the blower installed.  The individual installing the MagnaCharger Blower should refer to the service manual for your model.

Your MagnaCharger Blower comes with a couple of specialized tools required for installation. There is a $100.00 deposit on these tools since you’ll only need these tools once – regardless how many times you subsequently install or remove the blower from the engine.

CAUTION:  Disconnect the battery leads prior to continuing with the installation. Failure to disconnect the battery leads could result in injury or death as a result of fire or explosion while working in the vicinity of gasoline.

CAUTION:  Cleanliness is imperative in all aspects of installing the blower. Long term reliability will be directly affected by the care taken in ensuring no foreign materials enter the engine during any stage of the installation.

  1. Drain the fuel tank and remove.  Some installations have been able to complete the installation by simply raising the fuel tank approximately 4 inches at the rear, but access to the intake manifold will be significantly easier with the tank removed.
  2. Remove the air cleaner and carb, taking care to properly drain the fuel from the carburetor.
  3. Remove the front and rear exhaust pipes
  4. On those models with foot boards, remove the foot boards.
  5. Remove two of the three bolts holding the rear master cylinder, then with the third bolt still in place loosen it so that the master cylinder can rotate freely out of the way.
  6. Remove the cam cover
  7. On 1999-2000 models, remove the cam position sensor from the cam cover. Under no circumstances should the cam position sensor be installed in the blower body prior to the step specified in the installation procedure below or serious damage can result to the trigger wheel, or the cam position sensor – or both.
  8. After removing the cam position sensor, you will have no further use for the cam cover. Store it in a convenient place.
  9. Remove the spark plugs to aid in rotating the engine in subsequent steps during the following steps.
  10. With the Jim’s tools in the kit, retract the primary cam chain tensioner and install the retention pin to relieve tension on the cam chain. Note that a cam chain tensioner exists both on the inside and external side of the cam plate. Retention pins should be installed in both cam chain tensioners.
  11. Carefully turn the engine crankshaft until the alignment marks in the two cam gears are aligned. This will also ensure the crankshaft gear is properly aligned with the upper cam gear.
  12. Remove the bolts, washers, and sprockets from the crankshaft and the cam shaft. The cam shaft washer will not be used again, so you should store this appropriately.
  13. Using the precision tool supplied, install the CNC machined fixture over the crankshaft and bolt in place using the bolts provided. This tool is used to drill the tube dowel holes into the engine block in the precise position.
  14. Using the special modified drill bit (supplied with the blower), drill two existing bolts to the larger diameter of the drill bit. The bit has been modified to ensure the dowels are drilled to a precision depth.
  15. After drilling each of the two holes for the dowel tubes, remove the special adapter, and store it and the drill bit in the original box so it can be returned to MagnaCharger (There is a $100.00 deposit on this tool set).

CAUTION: Take note of the cleanliness of the engine, to ensure there are no foreign metal chips or scrapings in the engine as a result of the drilling.

  1. Remove the plug in the top of the Cam support plate by pulling straight up with a pliers. Replace this plug with the new plug supplied. This plug is the oiling jet for the supercharger. Press the plug in to ensure it seats well into the cam plate.

CAUTION:  This next step is one of the most important parts of the installation. Correct application of Loctite and the cleanliness of the parts cannot be stressed enough.

  1. Clean the crankshaft inside and out, with electro cleaner, acetone or lacquer thinner.
  2. Clean the new sprocket/blower drive gear, then coat the inside of the “D” shape and the small recess with the #620 Loctite included.
  3. Reinstall the cam gear, and install the new crankshaft gear on the crankshaft. Rotate the engine as necessary to ensure the timing marks are all aligned. You may need to tap the blower drive sprocket ‘lightly’. It should be a snug fit!
  4. Clean the crankshaft bolt and put a drop on the threads with Red Loctite, along with coating the bold / shaft area.
  5. Tighten the crankshaft bolt to 22 Ft-lbs.
  6. On 1999-2000 models with the cam position sensor, place the new trigger wheel against the cam, making sure it locks into the raised flange on the cam sprocket.

CAUTION:  This next step is critical, and as a result of the extremely close tolerance inside the blower body, failure to comply is likely to result in serious damage to the blower or the engine – or both.

  1. Take the old washer from the crank bolt and drill it out to 3/8”. Use this washer along with the cam bolt and reinstall the bolt as per H-D instructions for your model.
  2. Using the Jim’s tool, release the chain tensioner on both the internal and external chain tensioners, then recheck the timing marks.
  3. Loosen the bolts that attach the intake manifold to the heads, then remove the rubber adapter on the intake manifold.
  4. De-burr the edge of the intake manifold if necessary to ensure you do not damage the o-ring on the blower manifold when mating the blower to the intake manifold.  Note that it is often easier to simply remove the intake manifold, and install it on the blower with the intake manifold removed.
  5. Lubricate the blower manifold with a small amount of grease to ensure ease of assembly.
  6. In the vent kit you will find a couple of 90-degree fittings. Install these in the heads for the top vent breathers. When screwing them into the heads, a tighter fit can be assured by using a small amount of Teflon tape or other type of sealer on the threads.

CAUTION:  This next step could result in the introduction of foreign material into the engine casing. Take extreme caution to ensure the right side of the engine is protected prior to starting this step.

  1. Using a cutting tool (Dremel is much preferred), remove approximately 3/16” from the upper right side of the engine casing as indicated by the replacement gasket (provided). If done with a tool such as a Dremel, this slight modification will never be noticed – even if at some time in the future the owner elects to revert back to the stock systems.
  2. Confirm that you are able to screw one of the replacement mounting bolts through the dowel tubes once inserted into the engine casing. You may have to shave a slight bit off the dowel tube to ensure you are able to thread a mounting bold through the dowel tube.
  3. Insert the dowel tubes in the engine casing.
  4. Install the gasket on the blower and position the blower to align up with the dowel tubes and the intake manifold. Install the new bolts (provided) and work the entire unit into position. You should find it a relatively easy fit – especially if the intake manifold has been previously mounted onto the blower intake.
  5. Torque the bolts to make the installation permanent.
  6. Install the cam position sensor if used, and re-route the wires to clear the exhaust.
  7. There are two positions on the ‘gear driven’ cover to allow additional head pipe clearance on some models. Install the head pipe, then rotate the ‘gear driven’ cover to the optimum position, and then torque those bolts as well.
  8. Install the front and rear exhaust pipes. Depending on the model, you may not require any modifications to the exhaust system at all. On a recent installation on a 2000 Fatboy, using Vance and Hines Long Shots, the only modification necessary was the front pipe was extended 3/8” by inserting a sleeve in the front header. This was a small enough change that the Vance and Hines chrome heat shields still fit with no modifications.
  9. Depending on the model, you may need to move the footboard outward. On both a Road King this was accomplished by installing a 1 inch spacer on the master cylinder bracket, and replacing the original mounting bolts with two inch bolts available at any hardware store. On a recent Fatboy installation, the footboard was moved outwards by inserting 12 washers under each bolt, then coating the washers with a black plastic sealer commonly used to build grips on hand tools. This not only provided a wider base for the mounting plates, but also provided superior rust protection at the same time.
  10. Tighten the four bolts on the intake manifold
  11. Install the upper blower brace by removing two bolts on the top, inboard side of the blower, and attaching the support plate between the blower and the motor mounts located on the left side of the engine.
  12. Modify the carb by following the simple instructions in the carb kit.
  13. Install the air cleaner and choke cable, using the replacement choke cable (provided).
  14. Reroute the throttle cables as desired to prevent interference, then attach them to the carb.
  15. Adjust the throttle cables to ensure smooth throttle operation.

CAUTION:  Always test for proper operation of the throttle cables prior to starting the engine.

  1. Reinstall the gas tank.  Note that following installation of the blower, owners will be required to use premium quality fuel.
  2. Reinstall the fuel line with a longer line than originally came off the bike. We do not include this fuel line since experience has shown most owners install one of their own preference anyway.
  3. Reinstall the vacuum line between the fuel petcock and the carb. This line is not included.
  4. Install the vent kit using the tubing provided. Experience has shown it fits well pointed immediately back from the rear vent, with a line approximately one inch long connecting it to the rear tube, and the other line approximately 8 inches long, running beneath the blower intake manifold, to the front vent.
  5. Reattach the battery leads.

NOTE:  The loctite will need 24 hours to cure before operating the engine for the first time.  Following reassembly, this will most likely be the hardest part of the whole installation!

After allowing the loctite to cure, turn the petcock on. It will require a few seconds of cranking with the throttle shut to fill the carb. The bike should start and idle as normal. If not, adjust the carb idle and fuel mixture. The proper idle speed should be around 1000 RPM.

NOTE:  We’ve seen the “check engine” light come on, and it will do this under hard acceleration because the parameters of the MAP sensor have been exceeded. We have not found any problems other than the light coming on.

If you have any questions or need assistance please call the Tech line @ 1-530-865-7010.