Introduction

If your Road Star is a 2003 or earlier model, you are a candidate for the dreaded starter spin problem. Starter spin happens when the generator rotor--which the starter is supposed to engage--comes loose from its shaft, and renders the starter useless. Yamaha changed the design of this part, to correct the problem, starting with the 2004 models. But, if you are blessed with one of those great, 98ci (1602cc) beasts, read on...

If--even once--your engine backfires through the carburetor when you are trying to start your bike, there is a chance that the torque of the engine--momentarily spinning backwards--can unscrew the bolt holding the generator rotor. When this bolt comes loose, there is nothing to keep the rotor bound to its shaft, because only friction holds it. That's right: no keyway, no flange, no spline--nothing but the friction of a tapered hub being pulled into a tapered shaft-end, by the compression of a single bolt.

It is recommended that you perform this fix in any of the following situations:

• If you're a victim of starter spin, of course. You will know this has happened when you press the starter button, and all you hear is the starter motor spinning at high speed, without turning the engine over.
• You have any other reason to open the generator cover--upgrading your stator, for example.
• You live in fear that it might happen at a bad time, like going on a road trip, or any inconvenient location, near or far.

• Lapping compound (a.k.a. grinding compound). You can use either fine or coarse (or both). Available at most autoparts and, probably, home improvement stores.
• Retaining compound, like Loctite® Bearing Mount RC609. Optional. This is similar to thread-lock. However, it is formulated to hold fast on threadless, keyless shafts (like the generator shaft). If you use this, the lapping compound, above, is optional. Retaining compound is only available from commercial suppliers. To find a supplier near you, you can go to www.loctite.com, click on your country, click on Distributors, and enter your postal code. Note: Thanks to Patrick Sills and the Delphi Road Star Project forum for this tip.
• Red (permanent) Loctite, or equivalent. Available at most autoparts and home improvement stores.
• Generator cover gasket. Yamaha part#: 5PX-15461-02-00 (this is the new part# and supersedes 5PX-15461-00-00).
• Exhaust header gasket, for the front pipe. Use either Yamaha part#: 3EG-14613-00-00, ($3 to $6ea), or AutoZone part#: Fel-Pro 23588, (less than $1.50ea).
• Generator-cover bolt washer. Yamaha part#: 90430-06014-00, optional but recommended. This is the little washer for the lower, long bolt.
• 2"x8" x 12" wood pieces (quantity: 1 or 2), or equivalent, if your bike's suspension has been lowered, and you do not want to drain the engine oil for this project. See next page for details.

• 5mm hex (Allen) wrench.
• 6mm hex (Allen) wrench, for the floorboard mount.
• 8mm hex (Allen) wrench, for Removing/installing the front exhaust header.
• 17mm socket, for the generator shaft bolt.
• A dead-blow hammer, or a piece of wood and a hammer--for coaxing the generator rotor from its shaft. Not needed if your rotor is already loose.
• A propane torch, optional, as a possible tool to help get the generator rotor free of its shaft. Not needed if your rotor is already loose.
• An impact wrench (and compressor) or breaker-bar socket wrench, for the generator shaft bolt. Not needed if your rotor is already loose.
• An impact wrench (and compressor) or large torque wrench, for the generator shaft bolt.
• A large, adjustable, open-end wrench (like a Crescent), to help hold the generator rotor while torquing. Optional. Alternatively, you could use a Yamaha sheave holder tool (# YS-01880. See the service manual for details).
• Razor-knife or gasket removal liquid (like Versa-Chem Gasket Remover spray), for cleaning off the old gasket remnants-- both available at most auto parts and home improvement stores.

This project can be done without draining the oil from the engine, as long as you do not upright the bike. This means: Leave the bike leaned over on its side-stand. Once the generator cover is loosened, you may lose a few tablespoons of oil, but unless your bike's lean-angle has been altered by lowering the suspension or something, no significant amount should spill out.

Tip: If you have lowered your suspension, you can increase the lean-angle by putting the tires on something very stable, roughly the same height as the amount you’ve lowered your bike. In other words, if your bike's rear suspension is lowered 1.5”, you can lay a short 2x8 board flat under the rear tire.

Unbolt the right-side floorboard bracket. It is held on by two, button-head bolts going into the frame. Be careful to support the floorboard assembly as it comes loose. This assembly is still attached by the hydraulic hose and the brake light wiring. Use a tool box or other support to lay the floorboard assembly onto.

Warning: If you just let the floorboard assembly hang by the taillight wires or hydraulic hose, you run the risk of breaking the wires to the switch, or damaging the switch itself.

Remove the front exhaust pipe.

Next, remove the two bolts holding the generator’s oil-delivery-pipe to the right-side of the engine. It is much easier to remove this pipe and the generator cover as one piece, rather than trying to separate them while on the engine. See photo below.

Unbolt, and then remove the generator cover and oil-delivery-pipe as a unit. Also note: there is a long bolt near the bottom of the cover that has a copper or aluminum washer. Keep track of (or replace) this washer, where it goes, and which bolt it goes with.

Tip: The generator cover is magnetized to the generator rotor. To remove the generator cover, you need to un-bolt it, pull or tap it free of its gasket seal, work it off its alignment dowels, and then pull the cover free with enough force to overcome the magnetic force.

Remove, and keep track of, the two alignment dowels. They have a tendency to slip out of your hands and fall into very frustrating places, so be careful.

Now that the cover is off, you can see what’s inside. Remove the generator rotor center bolt. The bolt is on very tight, unless it has come loose. To get the bolt loose you may need a long breaker-bar socket wrench or an impact wrench.

In addition, you may need to hold the shaft from turning. This can be done anyway you want. Here's some suggestions:

• Put the transmission in gear. Tip: Be sure you prevent your bike from rolling as you torque the rotor onto the shaft. For instance, you could have someone stabilize the bike for you while you tighten the bolt.
• Use a Yamaha generator rotor holder tool (sheave holder).
• Use an adjustable, open-end (crescent type) wrench on the rotor to counter much of torque.
• Use an impact wrench, as long as you can set it, and your compressor, to at least 115 ft-lbs of torque.

Finally, remove the generator rotor. It is only held on by friction, but it can be stubborn unless it has already come loose. See Caution Tip below. To break the friction seal between the rotor and its shaft, do any combination of the following:

• Thread the center bolt most of the way back in (by hand), but leave the bolt-head sticking out from its seat. Then smack the bolt with a plastic dead-blow hammer.
• If you don’t have a dead-blow hammer, you can rest a piece of lumber against the bolt and rap the wood with any type hammer.
• Heat the center area around the generator bolt (but not the shaft or bolt, as best you can) using a propane torch. Then do one of the above. Warning: Do not overheat.
• Try using a dead-blow hammer or piece of wood to rap around the sides of the rotor.
• Try removing the center bolt of the generator rotor, and using one of the hammer tricks listed above applied directly to the center portion of the rotor.
• Caution: Do not use excessive hammer force. To avoid damage to the generator shaft bearings, pull out on the rotor, as you rap it to free it.
• Use a large wheel/gear puller.

Caution Tip: The generator rotor is heavy. If the center bolt is not in when the rotor breaks loose from the shaft, it could fall out quickly. Take precautions to prevent injury to people, your bike, and the rotor by laying down a padded landing beneath the area, being ready to catch it, and keeping clear, as best you can.

If you will be using the retaining compound to bind the rotor to the shaft, you may skip this section, if you wish. See the Parts section above for details on retaining compound.

The photo above shows a stock generator shaft.

The friction-bond between the rotor and shaft must be improved. So next, put a small dab of lapping compound on your finger. Smear it on the tapered portion of the generator shaft, so that the compound completely covers the taper. See photo below.

Tip: The lapping compound I got came with both coarse and fine grits. I used coarse grit compound for the first few rounds. Then I switched to fine grit.

Slide the rotor onto the shaft. Be sure the starter-clutch gear-train is out.

As you apply about 10 or 15 pounds of inward pressure on the rotor, rotate it clockwise about 8 complete rotations.

Then reverse the direction of rotation and do another 8, or so, rotations.

By now, the grinding feeling of the compound should be feeling smoother than initially. If not, apply a bit more pressure and keep pushing and turning until it does feel finer--less gritty.

Next wipe off the compound from both shaft and rotor. Check the shaft and rotor for high and low spots--which will show as a darker or lighter grey color.

Repeat the entire lapping process until no more high/low spots are found. Caution: Do not repeat this process more than 5 to 6 times however, as you may wear the taper down to where the shaft-end contacts the rotor's end-shoulder. This would ruin the rotor's ability to make a strong bond with its shaft. In other words, don't try to get a clean lapping all the way to the shaft's end. Leave the last eighth inch or so unfinished.

Use paint thinner or other solvent to thoroughly clean the generator shaft taper, the rotor taper-hole, the center-bolt, and the shaft threaded hole. See photos below.

Now is a good time to clean the gasket surfaces of old gasket remnants. Do this for the gasket surface of the engine case, as well as the generator cover. Be sure to wipe up any particles that may fall in.

Next mount the starter-clutch gear on to the rotor, if it came off. It just presses on. See photo below to see what they look like when separated.

Next, apply either retaining compound or red thread-lock to the following (Note: see Parts section above, for details on this):

• The tapered (lapped) section of the generator shaft
• The rotor taper-hole

Now, apply red thread-lock to the following:

• The shaft end-bolt
• The shaft threaded hole

Be careful to immediately and thoroughly wipe off any liquid that spills on any other areas. Then slide the rotor assembly on to its shaft, and thread the end-bolt and washer on.

Bolt and torque the shaft end-bolt to at least 115 ft-lbs. You can stabilize the generator shaft using any of the following methods:

• Put the transmission in gear. Tip: Be sure you prevent your bike from rolling as you torque the rotor onto the shaft. For instance, you could have someone stabilize the bike for you while you tighten the bolt.
• Use a Yamaha generator rotor holder tool (sheave holder).
• Use an adjustable, open-end (crescent type) wrench on the rotor to counter much of torque.
• Use an impact wrench, as long as you can set it, and your compressor, to at least 115 ft-lbs of torque.

Now install the starter-clutch gear-train. See photo below.

If you separated the oil delivery pipe from the generator cover, bolt them back together now. Torque the bolts to 7.2 ft-lbs, which is 86.4 in-lbs. Be sure both ends of the oil delivery pipe have their O-rings installed beforehand.

Insert the generator cover's two alignment dowels back into the engine case. Then slip a new generator cover gasket over the dowels.

Tip: The generator cover is magnetized to the rotor. As soon as you begin installing the cover, it will be sucked in by magnetic force.

Bolt and torque the generator cover. Be sure to use a criss-cross bolt tightening pattern, tightening bolts evenly, just a little at a time. Torque the bolts to 7.2 ft-lbs. Remember, the two long bolts are the only ones that are not perimeter bolts.

Tip: The long bolt near the bottom of the cover has a copper or aluminum washer. I recommend you install a new washer at this point. I did not, and it leaked.

Bolt the oil-delivery-pipe back into its hole in the right-side of the engine case, using 7.2 ft-lbs of torque.

Reinstall the front exhaust pipe, preferably using a new exhaust gasket.

Tip: I do not recommend torquing the exhaust header-flange nuts, as the flanges on many aftermarket exhaust systems are thinner than stock, and bend easily. Just tighten moderately. Then after your first few rides, check the nuts again.

Reinstall the right-side floorboard assembly by torquing the two button-head bolts under the floorboard assembly to 35 ft-lbs.

Caution: Be sure you do not attempt to start your bike for 12 hours or more, depending on the dry-time of the red thread-lock liquid.

Now relax, knowing your starter system is much less likely to fail you when you need it most.

Ride on.

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.

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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.

Comments (10)

Starter spin Written by Synagris, on 05-15-2009 18:55 I have a 06 roadstar 1700 silveradon bought straight from the crate last year...The starter spins..whirls when shutting down no matter how short of a time it's been running. This can't be right.... I asked the dealer service techs and was told that it was normal. From the looks I get when I pull up and shut it down tells me other wise, has anyone got the same issue or a clue as to what the heck is going on here..

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