This article is one of a series that describes how to disassemble, work on, and reassemble the Road Star engine. This particular article identifies skills required, lists parts selection, gaskets (and other consumables) needed, and tools recommended. It also offers comparative ways to estimate project time. Lastly, this document deciphers Yamaha bolt part numbers and lists a few important errors found in the Yamaha service manual. See the Complete Engine Tear Down, Orientation article in this series for details of other aspects of engine details.

Be sure you refer to the service manual through all phases of this project.

In my opinion, cleanliness, orderliness, and attention to detail are required.

Do not attempt this level of work unless you have a fairly complete tool set--and you know how to use it all. See the Tools section of this article for details. You should also have some experience in taking engine covers off--how much force to use, and where to apply it.

If you are not planning to remove the entire engine from the frame, and split the crankcases, the patience and skills needed are primarily in the following areas:

• You must be able to follow service manual instructions to rotate the crankshaft into proper position to place cams, rockers and pistons in proper syncrony.
• You'll need to be able to install piston rings on to the pistons, and then install pistons into the cylinders.
• You should have experience in properly torquing bolts.
• You'll need to install and adjust the valve train.

Even if you've never done this before, but you are patient, mechanical, and methodical--and you're not shy to ask for help--your chances of building a strong, long-lived engine are good.

If you are contemplating splitting-the-cases for your project, you will also be required to do the following:

• Properly form a very large, liquid-paste gasket.
• Keep track of many more parts (large and tiny) for a much longer time.
• Remove and install a complete (though simple) transmission.
• Know how to thoroughly clean and dry (or replace) pressed-in ball bearings.

If you hate asking for help, and you avoid looking things up in manuals, then working on the innards of your engine may not be for you.

Parts listed here are for your assistance. Do not take part numbers as gospel. You must verify them for yourself. Yamaha changes part numbers; I make mistakes. Exercise diligence. Yamaha parts explosion diagrams and part numbers can be found online on many Yamaha parts suppliers’ websites. They can also be found at www.StarMotorcycles.com. Though websites are subject to change, the current, direct web-address for Yamaha parts listings can be found at www.StarMotorcycles.com/star/parts/.

Below are the part numbers you’ll need. Most are required; some are optional, depending on whether or not you’re disassembling the entire engine, and if you’re disassembling all the subassemblies. I tried to indicate, “Optional” when appropriate. Also see the Complete Engine Tear Down, Orientation article for more information on what parts of the engine you’ll be disassembling.

Gaskets and Oil Seal Part Numbers Listing

• Exhaust header gasket, Yamaha part#: 3EG-14613-00-00, ($3 to $6ea). or AutoZone part#: Fel-Pro 23588, (less than $1.50ea).
• Cam cover (deep one), Yamaha part#: 5PX-12286-00-00, GASKET, DECOMPRESSION
• Cam cover (chrome cover), Yamaha part#: 5PX-15462-00-00, GASKET, CRANKCASE COVER 3
• Clutch cover, Yamaha part#: 5PX-15451-00-00, GASKET, CRANKCASE COVER 1
• Oil tank/Cap, Yamaha part#: 4WM-17932-00-00, GASKET, 3. Optional. Needed only if you’re disassembling the transfer case. See the article, Disassembling The Transfer Case in this article series, for details of how this can be avoided.
• Transfer case- skinny case, Yamaha part#: 5PX-17929-00-00, GASKET 1. Optional. Needed only if you’re disassembling the transfer case.
• Transfer case- oil pump, Yamaha part#: 4WM-13116-00-00, GASKET, PUMP CASE. Optional. Needed only if you’re disassembling the transfer case.
• Transfer case- little washer gasket, Yamaha part#: 4WM-17931-00-00, GASKET 2
• Generator cover, Yamaha part#: 5PX-15461-02-00, GASKET.
• Generator-cover bolt washer, Yamaha part#: 90430-06014-00, GASKET. Optional but recommended. This is the little copper or aluminum washer for the lower, long bolt.
• Cylinder base (2)--should come with Big Bore Kit, if performing a big bore build.
• Head (2)--should come with Big Bore Kit, if performing a big bore build.
• If using stock cylinders:
  • Cylinder base (all years), Yamaha part#: 4WM-11351-00-00, GASKET, CYLINDER
  • Head gasket (’99 – ‘03), Yamaha part#: 4WM-11181-00-00, GASKET, CYLINDER HEAD 1
  • Head gasket (’04 – ‘05), Yamaha part#: 5PX-11181-00-00, GASKET, CYLINDER HEAD 1
  • Head gasket (’06 – ‘07), Yamaha part#: 5PX-11181-01-00, GASKET, CYLINDER HEAD 1
• Valve cover – Spacer, (black metal), as needed,
  • Yamaha part#: 4WM-11193-00-00, GASKET, HEAD COVER 1, for ’99 - ‘03 only
• Valve cover - Top, (black metal), as needed,
  • Yamaha part#: 4WM-11194-00-00, GASKET, HEAD COVER 2, for ’99 - ’03 only
  • Yamaha part#: 5VN-11193-00-00, GASKET, HEAD COVER 1, for 2004+ only
• Rocker Base (black metal), as needed,
  • Yamaha part#: 4WM-11182-00-00, GASKET, CYLINDER HEAD 2, for 1999-2003 only
  • Yamaha part#: 5VN-11182-00-00, GASKET, CYLINDER HEAD 2, for 2004+ only
• Transfer case, middle driven shaft, bearing oil seal, (if you're pulling bearings out), Yamaha part#: 93102-40330-00, OIL SEAL
• Transmission output shaft, bearing oil seal, (if you're pulling bearings out), Yamaha part#: 93103-38184-00, OIL SEAL
• Transmission axle-and-crankcase ball bearings: See the article, Working on the Disassembled Engine, in this series for part numbers and detailed information
• Rubber oil seals for Pushrod tubes, as needed,
  • Yamaha part#: 4WM-12152-00-00, SUPPORT, ROCKER AR for 1999-2003 only
  • Yamaha part#: 5PX-12215-00-00, CAP, TENSIONER CASE for 2004+ only
• Valve stem seals, (qty: 8), if you will be taking out the valves Yamaha part#: 4KM-12119-00-00

O-Rings Part Numbers Listing

Replace O-rings as needed, only.

• Tiny ones for lifter-block area, Yamaha part#: 93210-48364-00, O-RING
• Lifter-blocks (2 sizes), Yamaha part#: 93210-54175-00, and 93210-54452-00, O-RING
• Pushrod Tubes,
  • Yamaha part#: 93210-472A9-00, O-RING (upper), for 2004+ only
  • Yamaha part#: 93210-40745-00, O-RING (lower), for 2004+ only
  • Yamaha part#: 93210-472A9-00, O-RING (upper and lower), for 1999-2003 only
• Thin-thin one for primary-drive-shaft, Yamaha part#: 93210-30660-00, .O-RING
• Thin-thin one for middle-driven-shaft, Yamaha part#: 93210-30660-00, .O-RING
• Thick-huge one for primary-drive-shaft, Yamaha part#: 93210-750A1-00, O-RING
• Tiny ones for crankcase oil cross-over tube, Yamaha part#: 93210-10001-00, .O-RING
• Oil filter bracket (2), Yamaha part#: 93210-23326-00, O-RING
• Intake manifold (2), non-aluminum type,Yamaha part#: 93210-505A4-00, O-RING

Other Parts Listing

Warning: You must verify all these numbers with your supplier, as numbers changes periodically, and I may have misprinted something.

• Piston Rings (’99 – ’03 only), Yamaha part#: 34L-11610-00-00, PISTON RING SET (STD), if using stock bore pistons.
• Piston Rings (’04 – ’07 only), Yamaha part#: 5PX-11610-00-00, PISTON RING SET (STD), if using stock bore pistons.
• Piston Wrist-Pin Circlip, Yamaha part#: 93450-24028-00, CIRCLIP, Qty needed: 4
• Tab-lock washer for transmission primary-drive shaft, Yamaha part#: 90215-30233-00, WASHER, LOCK
• Tab-lock washer for middle-driven shaft, Yamaha part#: 90215-30233-00, WASHER, LOCK
• Copper washers for external oil lines on left side engine (qty: 2, & qty: 1), Yamaha part#: 90430-10188-00, 90430-08119-00, GASKET
• Copper washers for sight plugs 9 total, highly recommended, Yamaha part#: 90430-05126-00, 90430-08119-00, GASKET
• Oil Filter, see your owner’s manual for details.
• Spark plugs (qty: 4), see your owner’s manual for details.
• Oil driven gear, only needed for 1999 – 2001 engines. See Failed Parts to Watch For in this website for details. Yamaha part#: 5PX-13360-00-00

• YamaBond.
• Plenty of clean shop rags.
• Small, new, sealable, baggies (or equiv) for temporary storage. Quantity: 10 to 20 or so.
• Large, sealable, freezer bags for small assemblies like oil-pump, shift-shafts, etc. Quantity: 5 or so.
• Plastic shopping bags or garbage bags for larger assemblies like crank and connecting-rods, generator, transmission assembly, starter, carburetor, etc. Quantity: 5 or so.
• Blue painters' masking tape (my tool of choice for covering holes for safety while assembling. Also good for labeling parts, and leaving yourself notes). Quantity: 1 roll. Available at hardware, and home improvement stores, etc.
• Wire-ties. Quantity: 4 to 6. Available at most auto parts and home improvement stores.
• Motor oil: Non-Energy conserving. No friction modifiers. 4+ quarts. I use 10W40 for break-in.
• Transfer case gear oil. 0.42 quart. SAE80API, GL-4, Hypoid Gear Oil. Available at Yamaha dealers. I use Mobile-One full Synthetic 75W-90, hypoid gear oil, but other gear oils in this range will work as well.
• Assembly Lube. 1 tube. Available at most auto parts and home improvement stores.
• Anti-Seize. 1 tube. Available at most auto parts and home improvement stores.
• Blue (non-permanent) thread-lock liquid. 1 tube. Available at most auto parts and home improvement stores.
• Red (permanent) thread-lock liquid. 1 tube. Optional. Available at most auto parts and home improvement stores. Only needed if performing the Starter Spin Fix. See details in the Fixing the Starter Spin Problem article in this website.
• High-heat gasket maker (like Versa-Chem high temp red RTV silicone). 1 tube. Optional. Available at most auto parts and home improvement stores.
• Gasket removal liquid (like Versa-Chem Gasket Remover spray), for cleaning off the old gasket remnants. Available at most auto parts, and home improvement stores. Alternatively, you could use a sharp scraper if you’re extremely careful--not recommended.
• Xylene (to thin Yamaha Bond for valve cover gaskets). Quantity: 1 quart. Optional. Available from most hardware, and home improvement stores.
• Paint thinner or other cleaning solvent. Quantity: 1 or 2 quarts. Available from most hardware, and home improvement stores.
• Pipe cleaners, for cleaning bearings and oil journals in crankcases. Available from most art supply and craft stores. Quantity: 10 to 20 or so.
• Latex or nitrile gloves, recommended. Available from most hardware, home improvement, and tool stores. Quantity: 10 to 50 pairs, depending on how much work you do.

• Road Star Service Manual. There are manuals for 2003 and earlier models, and ones for 2004 and up models. These available in Acrobat Reader versions, on-line, or printed.
• Air compressor for parts cleaning and operating pneumatic tools, like an impact wrench. Optional but recommended.
• Nippers (wire-cutters) for wire ties.
• Metric hex head socket set.
• A 5mm hex, long reach wrench (preferably with ball end) for getting in hard to reach places like valve covers and timing cover.
• Metric socket set with extensions.
• Large sockets: 28, 34, and 36mm. I borrowed mine from my local auto parts store, on a no-charge rental basis. These are for the front drive-pulley nut, the clutch basket nut, and the transmission drive axle nut.
• 30mm Torx head wrench, if the generator stator is to be replaced.
• Large, adjustable, open-end wrench (aka Crescent) or Yamaha sheave tool (# YS-10880), for the generator rotor. The Crescent wrench can also be used for rocker/pushrod assembly. See details in the Assembling the Generator Area article in this series.
• Heavy duty hold-down strap or Yamaha clutch holder tool for removing/installing the clutch basket. See details in the Assembling Engine’s Left Side article in this series.
• Chip brushes, or 1/4" to 1/2" firm bristle brushes, for forming the crankcase gasket, and for painting the rocker base gaskets, if desired. See the Assembling the Crankcases article in this series.
• Hydraulic bearing-press, or oven and bearing 'punches', if transmission ball bearings are to be removed/installed. Instead, I just took mine to my Yamaha dealer for them to do--for about $70.
• Hydraulic bearing-press, or 36mm (or bigger) socket or bearing 'punches', if ball bearing oil seals are to be replaced.
• Large screwdriver, cold-chisel, or equivalent, for bending over tabs on locking washers.
• Dead-blow hammer or rubber mallet for separating cases/covers and miscellaneous other stuff. I tried my rubber mallet, but the plastic dead-blow hammer worked better.
• Plastic pot/pan scraper (spatula type), wooden shims, or equivalent, for separating cases/covers. Optional.
• Motorcycle center lift, preferably hydraulic.
• Auto jack-stands, for supporting the engine during removal / installation (Qty: 2, if two people. Qty: 4, if working solo).
• 3/8" to 7/16" (10mm) steel rods, (Len: 3 or 4 feet, Qty: 2). Or other tools, for removing / installing engine. Optional, but very helpful.
• Four to six, 3’ pieces of 2”x6” or 4”x4” wood blocks for resting/supporting frame & engine.
• 1"x4"x 4' (or five foot) boards for easing the engine out of the frame--if you're working solo (qty: 3 to 4).
• 1”x2” x 7” sticks for supporting the pistons during reassembly. (qty: 2).
• Large tweezers, for installing and removing small parts.
• Magic marker (ie Sharpie) to identify contents of bags, and many other uses.
• Waste bin.
• Chair or stool.
• Torque Wrenches. I recommend one for high torque use--like above 15 ft-lbs--and a sensitive one for torques below 15 ft-lbs.
• Long breaker-bar socket wrench or impact wrench.
• Dial indicator and base, for adjusting valve rocker sync. Optional. Note: Instead, you can also use the non-dial indicator method of Joel's (Odo). See the Valve Adjustment articles, and the Adjusting the Valve Sync section of the Assembling the Top End article in this series for details.
• Open-end and box wrenches, or combination wrenches--metric.
• 10mm open-end wrenches (qty: 2), if you will be installing adjustable pushrods.
• Small, 4-5mm socket (or equiv, like a small adjustable, open-end wrench) for valve 'sync' adjustment bolt, which has a square head. See the Adjusting the Valve Sync section of the Assembling the Top End article in this series for details.
• Feeler gauge set for rings and valve sync adjustment.
• Knee-pads, as needed.
• Battery charger--motorcycle compatible--for maintaining the condition of your battery. Optional.
• Digital camera. Optional. This will allow you an easy way to show others how you're doing--tool sellers, on-line mentors, parts suppliers, and friends.

Miscellaneous Items (Parts and Tools)

• Parts: Alignment dowels, as needed, if any are found to be rusted or damaged.
• Tool: Bent over copper washer (or equivalent), for locking gears while working with cams, etc. See photo.
• Tool: Metric Tap & Die Set. Since the engine is mostly aluminum, you must watch out for thread galling, with bolt removal. As you remove it, the bolt won't feel like gets any easier to unscrew. This is a much different feeling from bolts that have been assembled with thread-lock. The result of galling is, some of the threads become torn. If minor galling happens, you must 'chase' (re-thread) both the bolt threads and the hole. Be sure to use anti-seize on such bolt-holes to reduce the chances of further issues.
• Part: Helix Coil, as needed. If chasing does not remedy the parts, you must use a helix coil. Note: Installing a helix coil is beyond the scope of this document.
• Tool: Temp Tank #1. Optional. A one-gallon gas-can that has been rigged with a little petcock near the bottom. I hang mine overhead, above the bike, with an adequately long fuel hose hooked to the carb. This way I can run the engine in the garage (with the door open, of course) without having to hassle with repeated gas tank removal and installation. The petcock I used is similar to: www.mfgsupply.com/m/c/20-868.html?id=iyivbixm, 20-868 - 1/4" Nipples Straight Cut-Off Fuel Valve, cadmium plated, low pressure valve. Replaces OEM #: 07-403. I installed a ¼” ID rubber grommet into a hole I cut into the can. Then I used gas resistant gasket maker around the hole and around the valve stem.
• Tool: Temp Tank #2. Optional. A half-gallon auxillary fuel tank that has a little petcock at the bottom. Refer to Build a Cheap and Inexpensive Aux Fuel Tank for details. I welded a nice mount to fit in where the stock tank would normally go, with an adequately long fuel hose hooked to the carb. This way I can ride the bike and make tuning adjustments, without having to hassle with repeated gas tank removal and installation. See photo below.

Time Needed

Time is a huge variable. Skill and familiarity usually means speedy. For example: an experienced mechanic, building a 108ci (or PR 110ci) engine, could do the entire project in a weekend or less--assuming they had all parts available. As another example, the Road Star transmission recall, which involved splitting the cases, was done by Yamaha mechanics in only eight hours--give or take.

By contrast, I took nearly five months to do a complete build--a few hours at a time. My tear-down was more complete than either example above. I was also unfamiliar with the engine details. Your project will likely be more than a weekend, but less than five months.

On average, I devoted one full day per week. I also put in an hour here and there after work, each week. Basically, my time breakdown was like this:

• 30 days -- To order and receive my parts. I was reluctant to start until I had my parts in hand.
• 10 days -- To tear the engine down, including labeling and storing parts.
• 7 days -- Waiting for my Yamaha dealer to remove transmission (and transfer case) bearings.
• 14 days -- For the machinist to do all the initial machining work on the heads, cylinders and crankcases.
• 7 days -- To box up engine cases and take/send to DK Powdercoating. This was mostly due to my work schedule.
• 14 days -- For powdercoating.
• 14 days -- For me to do custom details like head-port smoothing and cooling-fin tip polishing.
• 21 days -- For the machinist to finish machining (valve job, honing cylinders). He was back-logged.
• 30 days -- To reassemble everything, taking my time to feel sure about getting everything right--checking, photographing, and rechecking each subassembly. This also included fitting my new carb to the bike and fabricating a new way to attach it to my air cleaner.
• 7 days -- To get it running well enough to ride to work with confidence that I wouldn't get stranded.

It adds up fast.

Deciphering Yamaha Part Numbers for Bolts

The information below can be learned, from within the part numbers for Yamaha bolts--with many exceptions to the rule. The first five digits may indicate what type of head the bolt has--flange, straight, button, etc--as well as hardness. However, there are so many exceptions, this information is not reliable. The center five digits of the part number are usually (but not always) as follows:

• Digits 6 - 7 are usually the bolt diameter (in mm)
• Digits 8 - 10 are usually the bolt length (in mm)

You can use this information in searching for the correct part number to purchase, or for verifying which bolt is to be reinstalled where.

Service Manual Errors

• Pg: 2-34 of the 1600 Road Star manual. Item #17 is shown routing to left side of engine. It actually goes to right side.
• Rear axle torque is way too much. The torque should be around 65 to 85 ft-lbs.

Proceeding to the Next Step

To access related articles, refer back to the Complete Engine Tear Down, Orientation article in this series to see which additional article(s) best addresses your situation.

Questions should be asked in our forum (Use discuss link below). The forum is very active and you stand a good chance of getting your questions answered there. If you would like to leave feedback for the author, or have additional information you think will benefit others, please use the comment section at the bottom of this page.

Discuss this article on the forums. (1 posts)

DISCLAIMER: This information and procedure is provided as a courtesy and is for informational purposes only.  Neither the publishers nor the authors accept any responsibility for the accuracy, applicability, or suitability of this procedure.  You assume all risks associated with the use of this information.  NEITHER THE PUBLISHERs NOR THE AUTHORs SHALL IN ANY EVENT BE LIABLE FOR ANY DIRECT, INDIRECT, PUNITIVE, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, OF ANY NATURE ARISING OUT OF OR IN ANY WAY CONNECTED WITH THE USE OR MISUSE OF THIS INFORMATION OR LACK OF INFORMATION.  Any type of modification or service work on your motorcycle should always be performed by a professional mechanic. If performed incorrectly, this procedure may endanger the safety of you and others on your motorcycle and possibly invalidate your manufacturer’s warranty.

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