All Road Stars built before the fuel injected, 2008 models vary their ignition timing via a small sensor attached to the carburetor. This sensor is called the Throttle Position Sensor -- or TPS. Theoretically, the more you twist your right wrist, the more demand is placed on the engine, and the less the ignition timing should be advanced. In real life riding this theory has a few holes, but in my experience the TPS still out-performs other available methods for the Road Star carburetor, including V.O.E.S. and M.A.P. (See the Installing a V.O.E.S. article in this website for more information on VOES and MAP). The TPS offers the potential for better torque at all speeds, better fuel economy, and longer engine life.

Unfortunately, few aftermarket carbs include a way to connect the TPS. Carburetors built for high performance (racing) applications have no need for variable ignition timing since it is assumed that the engine demands will always be maximum, and therefore the mechanic just sets the timing to a fixed point.

For many owners however, the temptation to upgrade from the stock carb to achieve more power, quicker response, more reliability, and easier tune-ability outweighs the benefits that the TPS provides, and so the TPS comes out with the stock carb. In an effort to have both a better carburetor and proper ignition-advance, a few ingenious owners have fabricated custom brackets for certain, popular, aftermarket carbs to adapt their stock TPS. However, most have simply ignored the engine's needs for variable ignition timing in their thirst for more peak horsepower.

My design has one moving part: an axle. The axle is rotated via an integrated pulley that accepts the throttle pull cable -- which has been slightly shortened. The end of the little axle is fastened directly into the TPS, which moves the same way as it did in the stock carb. Another, tandem pulley, integrated into my axle, accepts a very short cable that, in turn, actuates my aftermarket carb.

My project construction boiled down to just seven, simple, yet time consuming steps: (1) Fabricating the axle, (2) Fabricating a basic pulley, (3) Finishing the pulley for dual cables, (4) Fabricating the framework or plates, (5) Fabricating a mounting bracket and cable receiver, (6) Ordering new throttle cables, and (7) Fabricating a dust cover.

Some Road Star owners love the stock, 40mm Mikuni, CV carburetor. Others favor their aftermarket Mikuni HSR 42mm or 45mm, while still others are sold out to the S&S Super-G, using an aftermarket manifold.

However, it is hard to argue with the incredible performance of the Genesis Big Air, 48mm carb from P.S.I. It is an enormous improvement, as others have also written. See Appendix-A for more information and my experiences with this amazing carburetor.

This is not an inexpensive project, compared to some others you could do. However, in terms of cost per power improvement, it begins to look very reasonable. Prepare for sticker shock in the neighborhood of $1,500 for the priviledge of esclating yourself into the realm of fuel injection equivalent power.

Now, with my Genesis carb, I can keep up with the fuel injected models, without unduly sacrificing gas mileage. Frankly, when you compare the performance and price of fuel injection to the Genesis carb, it doesn't look so pricey anymore.

Here’s what I did to install my Genesis Series IV carb on my Road Star.

Note: This article applies to model years 1999-2007. If your Road Star is a model year 2008 or later, your bike is fuel injected, and has no carburetor.

Important Note: This article assumes you have some mechanical familiarity with the carburetor of your bike. If you question your skill in working with the intake systems of motorcycles you should not attempt this project (in my opinion).

Items Needed:

• Kelsey Hayes type master cylinder: L 1979-1983 Harley FX or 1980-1981 XL Sportster Product Link
• 3/16”x 1” flat stock approximately 4” long.
• 2 bolts 5/16”x 2 ½”
• 2 5/16”chrome acorn nuts
• 1 5/16” x 24 banjo bolt
• 1 5/16” solid rod (purchase at hardware store)
• 1 brake light switch for 67-79 Chevy Nova OEM# 1261219
  

This was one of the easiest projects I have ever undertaken on my bike. Total time was about 2 1/2 hours. It probably could have been done in 45 minutes to an hour but I was taking pics and making notes. I recently acquired a set of "Hurricane Studded" bags from Mike Battles at Custom Classic Saddlebags, which happened to come with a set of Easy Brackets. The Hurricane's are generic bags not made specifically for the Road Star (more about the bags at the end of the article), so this set of instructions should apply to just about any bike with Generic bags assuming the correct Easy Bracket kit is ordered to fit the bike.

Parts:

• Easy Brackets Kit (part number YMA-R2BR for Silverado with stock backrest)
• 4 Docking Posts (in kit)
• 4 8mm polished ss button head bolts (in kit)
• 8 3/8 x 1 black button head bolt (in kit)
• 8 3/8 nylon locking nut (in kit)
• 8 3/8 fender washer (in kit)
• barrel key (in kit)
• Hurricane Studded bags from Custom Classic Saddlebags

Mark Garetz at www.vstar1100.com originally put this idea together.  Mark Cole (Mark7) adapted it to work on his Road Star, and after a very favorable reception on our forum, agreed to write out this set of instructions for the benefit of other members of the Clinic.

Parts List: 

• 2 Sealed Beam Spotlight Housings - J.C. Whitney part # 1JA 019960 - $24.99/unit JC Whitney Part Link
• 2 Sealed Beam Spotlights - J.C. Whitney part # 1JA 019962 - $10.99/ unit JC Whitney Part Link
• 2 Cruiser Customizing 3-piece bar clamp - $7.00/unit Part # CC-FRAME-CLAMP Cruiser Customizing part link
• *1 Toggle Switch SPST (optional) waterproof version - $5.00 part(s) 16535, 16536 go2marine.com part link
• *1 Toggle Switch SPST (optional) non-waterproof version Radio Shack part # 276-624 Radio Shack part link
• Silicone Sealant – Just a dab.
• 2 Insulated Spade Connectors.

*Toggle switch is an optional item and you need only 1: Get either the waterproof or non-waterproof version

Tire changes, belt changes, and swing arm maintenance are just a few of the reasons belt adjustment and rear wheel-alignment are part of Road Star ownership. By learning to do it yourself, you can save some cash, and make sure the job gets done properly.

If your rear wheel is not pointed in the same direction as your front wheel, tires wear out more quickly, the bike feels less balanced, and your drive belt may quickly wear.

There are at least three ways to align your rear wheel:

• Match the rear wheel’s alignment to the front wheel’s straight-ahead position.
• Align the rear axle’s alignment to the frame’s alignment by matching it to the swing arm pivot.
• Align the drive belt to track properly in the rear drive pulley.

The first method is covered in another Road Star Clinic article: The $6 Wheel Alignment Jig. Its author suggests tying straight edges to each side of the rear wheel, then adjusting the rear wheel until both straight edges are equidistant from the -- centered -- front wheel. While this method is clever, cheap, and potentially accurate, it won't work with a hydraulic center lift (it obstructs the straight edges). And I don't really have the garage space or the budget for a proper, non-obstructing lift. (See “The $6 Wheel Alignment Jig” article in this website for details.)

The second method, ‘Aligning the rear axle to the swing arm pivot,’ is the way Yamaha recommends, although they offer no opinion -- pro or con -- for other methods. This method aligns the rear wheel by measuring the distance from the rotational center of the swing-arm pivot to the rotational center of the rear axle on each side the frame. When the distances on each side of the bike are identical, the rear wheel must be pointed straight. This should also make the drive belt track properly within the pulleys, theoretically. Note: This is currently the method I use and recommend, too.

The third method, 'Aligning the drive belt to track properly within the rear drive pulley,’ can be highly accurate and doesn't depend on measurement devices, but it is often very time consuming, repetitive, and potentially frustrating. With that said, I admit that this was my method of choice for 4 years, and an estimated 25 alignments (due to the many related mods I did).

This article gives several variations and refinements on the standard alignment procedure to reduce error and guess work from the task. It's a fairly simple and quick procedure, and doesn't take many tools.

Complete Documentation of a Big Bore Project!

Today we are releasing a new series of articles on the Clinic that document a complete engine tear down and reassembly. Randy Fox (associate Publisher here at the Clinic) decided to go big bore on his Road Star and documented the process from start to finish. This is an incredible addition to our Tech Tips library, with a total of nineteen articles from start to finish.

In order to make it easy to follow, and to keep the structure easy to navigate, we have created a new category under our "Engine" section in our Tech Tips called "Engine Tear Down and Reassembly Series". As is usually the case with Randy's Tech Tip articles, each is well thought out, easy to read, and easy to understand. Randy has taken the time to create an index for the whole series that briefly explains what each article is about, and the order they should read. This series is a must read for any Road Star rider who likes to maintain their own bike.

About this series: