81 - 83 Virago Starter Systems
A Gen I Virago Starter (above)
The earliest Virgos Starter Systems have been around for over twenty years, and the few original owners left probably have any starter problems well in hand by now. But most of these bikes have changed owners, and each new owner is likely to face some sort of starter problem sooner or later. So we get lots of questions and also hear a lot of stories and opinions about what should be done in the way of fixes. Often, dealers won't have all the answers, or mechanics unfamiliar with these bikes may just want to start replacing expensive parts. Some shops will simply tell you, "That's just the way they are so you'll have to live with it."
I have worked on a number of these virago starter systems, and have acquired some knowledge--often the hard way. There are actually several 'subsystems' involved. I will try to take them one at a time and describe the functions they perform, problems which can occur, and the fixes that have been used.
But note: Before undertaking any of the fixes described here, you need to carefully consider your level of competence as a motorcycle mechanic and whether you will be able to handle not just the fixes, but the disassembly and reassembly required to make them. You should also fully evaluate for yourself the information given here and understand the procedures described and the consequences of making mistakes. I can’t guarantee that you'll get good results. We offer this information only for your consideration. It's your bike. You must be ready to accept full responsibility for any work you do (or have done) on it, including work based on suggestions given in this paper.
For those undertaking there own work I would strongly recommend getting a Factory Service Manual (not easy to find these days) and refer to it as you go along. Clymer and Haynes also offer manuals on most models of Viragos, which can be helpful. The Haynes book on motorcycle electrics is a good general reference.
BEFORE CONDEMNING YOUR STARTER.......
* A hot battery is essential. A hot battery should be able to sustain a charge of around 12.5 volts. Charge your battery and let it sit a day. Then read it with a multimeter. If your battery can't hold in close to this number, buy a new one. Virago starters need all the voltage they can get to work right.
* Use good starting technique. It is not usually a good idea to open the throttle while the starter is turning, because giving the cylinders a full gulp of air increases compression--which the starter system then has to overcome to turn the engine. The starting fuel circuit in the carbs is designed to give the engine the fuel it needs to start. Once the engine catches, you can then 'blip' it.
* Try to discover and/or perfect a starting procedure (amount of choke, etc.) that works consistently for your bike. If your bike starts easily on the first or second hit, then you are not using this less-than-robust system very much. But if you have to try eight or ten times your starter system will clearly last not nearly as long.
THE IMPORTANCE OF STRONG ELECTRICS
Sometimes owners complain of intermittent starting problems. That is, the virago starter system works, then it doesn't, then it does. Or it works when the engine is cold, but not when it is hot. Or you just hear "clicks". This can mean that the system (actually the main starter relay) isn't receiving its full voltage. Causes for this kind of behaviour are often found in the connectors, switches, and other relays which make up the somewhat complicated starter circuit--with its several safety features in the form of cut outs, cut offs, etc. If you have any of these problems, checking and cleaning these connections (as well as grounds) is a good idea. A multimeter can tell you what kind of voltage you are getting. The rest of this paper assumes that you have good voltage to the hot side of the main starter relay when the starter switch is pressed. If you don't have good voltage, you need to get it before assuming that the starter system is bad.
The term "starter" actually refers to two components, the starter motor and the reduction gear assembly. See Figure 1. This combined unit is the barrel-shaped component you see on the front of your engine, below the cylinder. The two sections are held together by the two long bolts running lengthwise on the outside.
This is the electric motor that runs the system. Many mechanics think it is not overly powerful, and just barely up to the job. So it is important that the motor be at its best. What can go wrong with the starter motor? About the same things that can go wrong with any electric motor:
* Prolonged use will wear the brushes down, and when they get too short, they need to be replaced. Any manual (Factory, Haynes, Clymer) will give you the specifications on this. While you are at it, you can also gently clean the commutator (where the brushes brush) with fine (non-metallic) sandpaper until the copper color is restored. Shouldn't take much. Clean it thoroughly with solvent afterwards paying attention to the grooves between the bars. You don't want any copper particles in those grooves. Where the commutator is deeply scored (not common in these starters in my experience), they may need to be turned down on a lathe. In this case the mica insulation between the commutator bar segments will need to be undercut to restore separation of the bars. But this starts to become professional starter rebuilding type work and a new or rebuilt starter maybe your best course.
* Occasionally we'll see solder thrown out of the commutator due to overheating, or damaged commutator bars. In these cases you'll want a rebuilt or new starter motor.
* In rare cases one or more of the armature windings can go out. If the brush comes to rest directly over this bar on the commutator, the starter won't turn the next time your try it.
* Occasionally, the windings in one of the field coils will lose their insulation and short out, but if this happens (again, rare) the motor probably won't work at all. The manuals give tests you can perform to make sure there are no shorts. Sometimes shorts may occur in windings only when the starter gets hot, so the static tests are not always conclusive.
* Note that if the armature has to come out for testing or replacement, you'll find that the leads from the brushes to the field coils will seem to be in the way, but the armature will come out that end with a little finagling. Once the armature is out, you can do some clean up inside where the field coils are, as well.
* While you are in there, you should re-grease the smooth bearings with molly grease (not too much), and generally clean things up. When disassembling a starter, go slowly and make note of the number and location of shims and spacers and O rings. It's not a bad idea to draw a picture of the pieces as they come off so that you will know where to replace them. When reassembling the starter you should re-grease the smooth bearings with molly grease (not too much).
Few Virago starter motors that I have looked at are in really bad shape. When someone tells you that you 'need a starter rebuild' ask specifically what will be done. If it's just cleaning, lubing, and new brushes, you maybe able to tackle the job yourself.
BUYING NEW AND REBUILT STARTERS
When inquiring about a replacement starter you'll learn that you have a choice between "two brush" or "four brush" starter motors. Your bike came with a "two brush" motor where the field coil magnets are "field excited" electro-magnets--that is, activated by electric current. On the other hand, later four brush starters feature permanent magnets in the field coils. While the four brush design was introduced to the Virago in the late eighties, four brush starters are now available from the sources shown in the back for the earlier model Viragos, so you can buy one for any '81-'83 750 or 920, plus '84/'85 700's. The four brush starters are said to have somewhat more torque than the two brush version. Part of the reason maybe that the field coil magnets (being the permanent type) do not draw power to activate them, so that all the cranking power from the battery is available to turn the armature. Any two brush starter in good shape will certainly start your bike, but if I were going for a new or rebuilt starter, I'd pick a four brush.
Note that while the dimensions of the starter motor VS the reduction gear assembly varies between these two types of starters, the overall length of the assembled unit is the same, so that either type will plug right into to your engine.
Note also that later Viragos (all XV 1000's and 1100's, and XV700's and 750's from '86 on) have a redesigned starter system with a longer gear shaft sticking into the engine. So for all '81-'83 750's, and 920's, and for '84/85' 700's, be sure you are ordering a short shaft starter, whether it be two or four brush..
REDUCTION GEAR ASSEMBLY
This is the 'other piece' attached to the starter motor by the two long bolts. It houses a planetary gear system with two small gears (sometimes called 'moon' gears) toward the middle, and a ring, or orbital gear on the outside of them. The purpose of all this machinery is to reduce the speed of the rapidly spinning starter motor down to speeds that can be used to turn the engine. This is the home of the 'spinning ring gear'. Of course, the ring gear is not supposed to spin, and normally does not, because it is squeezed tight between the starter motor body and the piece that lies below it (the "locked" piece) in the reduction gear housing. Thin (I've measured them at 10 to 20 thousands) shims were placed between between the ring gear and the starter motor at the factory to assure adequate pressure on the ring gear when the two housings are pulled tightly together by the long bolts.
See Figure 2 for a picture of the two parts separated. The shims are seen hanging on the gear coming out of the starter motor. The ring and moon gears can be seen at the left.
over time, the bolts can stretch (and/or housings warp), causing the pressure to come off the ring gear enough to where it starts to spin in the reduction gear housing. When this happens (which it does quite commonly), no force is transferred into the engine to start it.
Why would Yamaha engineers adopt such a design? It is said that it was designed this way to handle extreme torque loads (like maybe a backfire while starting), in that the ring gear would slip (spin) before something else broke. In other words, a primitive starter clutch sort of thing. Maybe so. (Later model Viragos do have "real", sprag-type, starter clutches.)
When the ring gear starts spinning there are several alternative solutions:
* The book (dealer) solution has mostly been to add more shims, and then re-tightening the long bolts to restore the needed tension to stop the spinning.
* Mechanics quickly discovered, however, that the ring gear sits right on top of another ring which is keyed into the reduction gear housing; in other words, locked down tight. So an early alternative fix was to weld the ring gear to the piece below it. Once this was done, the ring gear would never spin again. Figure 3 shows the reduction gear housing with the guts out of it. You can see the lower (keyed/locked) ring on the left with the ring gear next to it on the right.
* A third technique is to clean off the ring gear and the lower ring thoroughly, and then JB Weld the two together. It is a tongue-in-groove fit, with lots of gripping surface. Apply the cold weld material in the groove, and then work the pieces back and forth until a good, solid mating of the surfaces is achieved. This method has the advantage of being a do-it-yourself job in the comfort of your own garage, without welding equipment--and it doesn't cost much. It is the fix I use. I usually put the original shims back in as well. I have (so far) never had a ring gear start spinning again. Figure 5 shows how the rings look when they are welded together.
* Yet a fourth possibility is to drill and tap holes through both rings and bolt them together. Teflon or plastic bolts have been used on the theory that they will shear under extreme pressure and thereby retain the "clutch" effect inherent in the original design.
* While you are in there why not re-lube all the gears with molly type grease. Try Honda Moly paste.
Are these permanent fixes risky because of the theoretical need for a starter clutch feature? I don't know for sure, but I have never heard of anyone ever shattering the reduction gear housing, or tearing anything else up because of a welded ring gear. I have seen a few cases where the idler gear shaft coming out of the reduction gear housing broke, but I think both of these failures happened in bikes where the 'fix wasn't in". Maybe just poor or ageing metallurgy. I personally think that the cold-weld technique is O.K., since it flat stops the spinning and is easy to do. But it does lock the ring gear to its housing and defeats any "clutch" function. So you need to make your own decision on this. Adding shims may work just as well, is also easy to do, and does retain the "clutch" feature, but with this "fix" the ring can conceivably start spinning again at some future time.
Note that the starter motor and the reduction gear housing are keyed together for proper orientation with a little flat key on one side. It is small and easily lost. Watch for it and see where it goes, so you can replace it properly. This little key is shown in Figure 3.
INSIDE THE SIDE COVER
Many Virago starter system problems with the Virago don't have anything to do with the above two assemblies, the ones you can see on the outside. They are caused by the gears, springs, and clips you find inside the engine side cover. To get to these you must remove the side cover, and you should have a good idea about what you're doing before you undertake this procedure. I cannot cover everything involved here. If you are going to attempt this for the first time, I would suggest you get a factory manual and use that as a guide. One thing you should absolutely do, is to draw a picture of the side cover on a piece of cardboard, showing the position of all the side cover bolts. Then punch holes for the bolts to go in. As you remove them, put them in these holes. These bolts are three different lengths, and if you just throw them in a pile, you'll have problems getting them back in the right holes. Now refer to the Parts Blowup Exhibit. I will try to describe the function of the various parts, and what can go wrong.
* FUNCTION: Gear #3 (Starter motor gear) is attached to the shaft (remember short shaft) coming out of the reduction gear assembly. Clip #2 grips gear #3 and provides a brake to slow the starter motor down once the starter has done its job and power to the starter motor has been cut off. The narrow part of the clip sits in a slot in the engine case to keep it from spinning. PROBLEM: If this clip has lost some of its tension it will not act as a good brake, and you will hear the starter motor and reduction gears spinning excessively after the bike has started. FIX: Replace the clip with a new one.
* FUNCTION: Starter motor gear #3 drives gear #9 which in turn drives the #4 idler wheel. The idler wheel has helical splines--on which sits gear #8. (The parts blow-up shows the splines on the idler wheel as straight, but they are actually helical). When the starter motor is activated, gear #9 causes the idler wheel #4 to spin, but idler gear #8 is kept from spinning by clip #7 and is thereby forced outward on idler wheel #4 to engage the teeth on the back of the flywheel/rotor (not shown) which sits on the end of the crankshaft. When the idler gear #8 reaches the end of its run (is engaged), the pressure of clip #7 is overcome by the torque of the starter motor so that idler gear #8 now starts to spin, thus turning the engine over. Clear? (As mud, probably!) PROBLEMS: If clip #7 has lost some of it tension, idler gear #8 can start to spin before it fully engages the teeth of the flywheel/rotor, and will tend to grind its way in, if it makes it at all. Is this hard on the gear teeth of idler gear #8 and also the flywheel/rotor teeth? You bet it is! Don't continue to use a starter which grinds on the way in! The idler gear is not cheap, but a new flywheel/rotor or renewed rotor is very expensive.
Note that since the engine comes to rest at pretty much the same position each time it is turned off (due to compression), idler gear #8 tends to engage the flywheel/rotor in the same stretch of teeth each time the bike is started. Some rounding of the flywheel/rotor teeth is par for the course, but prolonged grinding will trash this section of teeth on the rotor and mean you'll need to pull the rotor (not that easy) and replace it, or have the teeth renewed (more on that later). Note that assessing the flywheel/rotor teeth isn't always that easy with the flywheel in place. A little mirror can help. As for idler gear #8 some rounding is also usual, and it's a judgement call as to whether you should reuse it. But if the teeth look really chewed up, the gear should be replaced. Note also that idler gear #8 has hard rubber bumper material both sides of it, which gets worn or is sometimes gone completely. This would be another reason to start with a fresh idler gear number #8.
Some "mechanics" have reversed idler gear #8 to get to the 'fresh teeth' on the other side. The starter system will actually function for a while this way, but I would not recommend it as a fix. FIXES: If there is grinding on the way in, clip #7 should be replaced. Note that this clip is slightly different between 750's and 920's, so be sure to order the correct one for your bike. Idler gear #8 may need to be replaced, and damaged teeth on the flywheel/rotor may need to be corrected (new rotor or repair). In case it isn't obvious, seriously worn teeth make for poor engagement of the gears and thus poor starting. Finally, the small end of clip #7 sits in a slot in the engine casing where it slides back and forth with idler gear #8 as this gear thrusts forward and pops back during the starting procedure. The clip can, over time, wear a notch in this slot, which can cause the clip to hang up, which in turn causes poor disengagement of the idler gear when the engine starts and the starter is turned off. Find this slot and check it out. If a notch is found that can cause a hang, it needs to be carefully smoothed out (I use fine sandpaper) to make sure that clip #7 slides freely back and forth. You should not need to take off much material.
* FUNCTION: Spring #5 is the force that causes idler gear #8 to pop back out of engagement after the engine has started, the starter motor has cut off, and tension is off the system. PROBLEMS: Based on some recent inputs I have revised my thinking on this spring. I now think it is way too strong, and contributes to the the problem of idler gear #8 partially kicking out (that "clunking sound") when pressure comes off the system due to compression. (When a piston comes off Top Dead Center on a compression stroke during the starting cycle, the compression will push it down rapidly. This makes the flywheel speed up momentarily and the flywheel "outruns" the starter for a moment, taking pressure off the system. At this point the idler gear starts to kick out. It then re-engages ("clunks") when the compression effect is past and the starter system regains pressure from the starter motor.)
FIX: While I have personally not had chance to try the following fix In a bike, I now think a good thing to do is to cut this spring in half. I've done this to one and checked it with gears outside a motor. The spring seems to retain enough force to move idler gear 8 out quickly enough when the engine catches, but the reduced spring pressure should help solve the "kick-out" tendency discussed above. Others have tried it and say this fix is effective and helpful. I'll give it a shot on my next starter job, and offer it here for your consideration. I have had some input on this technique. One owner had a failure with a cut spring in which the cut end moved outward and grabbed the idler gear, preventing it from engaging. It seems clear to me that the uncut end should be placed against the idler gear--and I believe the failure would not have occurred if it had been mounted that way. A friend of mine has now repaired several starter systems using the cut spring-- without a problem. He bends the cut end inward so it hugs the "wheel" (helical splines part) more tightly, and files the cut end flat to seat a little better. We report, you decide.
Note that a weak starter motor will also contribute to the "kick-out" problem since it keeps less tension on the system
Finally, Yamaha came up with a 'fix' which you should be aware of. This is the 2mm thick 'plate washer' (old part #902-01356-68-00, new part #9999-03102-00) which is placed between the two idler gears. It has the effect of shortening by 2mm the throw needed to engage idler gear #8 with the teeth of the rotor, and so the idler gear has less time to think about spinning before it engages. See Figure 5 for a picture of the washer and Figure 6 showing it inserted between the idler gears when they are assembled on the helical idler wheel. But there is now a problem here. When you order this plate washer, instead of getting one 2mm washer, you now get two 1mm washers. Due to the chamfer on the end of #4 idler wheel a 1mm washer can drop down and hang up, whereas a 2mm washer is broad enough to avoid this little ditch. I won't use the two washers due to this, and have had some proper 2mm ones made (not cheap). Another solution is to have a good welder tack the two 1mm washers together thereby making one 2mm washer. Or with a little ingenuity and sweat you can possibly make one yourself. I've given the dimensions at the end of this paper. This was a cheap part, and an easy fix, but it is not any more. But still worth doing, I think. Note that the rubber bumper material (or lack of same) on idler gear #8 also influences the distance of that gear to the flywheel.
In summary, we have a weird and wonderful mechanical engagement system here which can work fairly well when the starter motor is strong and all the components are up to snuff. Generally, I have had good results rebuilding these systems, although I have to say that sometimes perfection as eluded me, and results were only just O.K. Should you attempt all these fixes yourself? Well it depends. Are you a reasonably good mechanic? Do you have a Yamaha Factory Service Manual for your bike? (Unfortunately Yamaha no longer offers them new and they can be hard to find) Is this your only ride, or more of a project bike? Pulling and reinstalling the side cover is a procedure beyond the scope of this paper and is not to be taken lightly. There are some tricks and you'll need to master the procedure if you are going to go in there yourself. Note that the starter motor/reduction gear assembly (the outside components) can be wrestled out of the engine without pulling the side cover, but you cannot reinstall it without pulling the side cover.
Whether you chose to tackle this project yourself, or not, hopefully this article has at least informed you enough so that you can handle things better with your mechanic and check to see that the work is being done right (This paper has been used more than once by owners to educate mechanics in Yamaha dealerships!) While early Virago starter systems will never perform flawlessly (at least in my experience) they probably worked pretty well from the factory, and can be restored to work reasonably well again. (And Yamaha engineers were thoughtful enough to install a little magnet near idler gear #8 to catch the metal particles thrown off in that region by all the crashing and bashing before they circulate throughout the engine. If you pull the side cover, you'll see it. Be sure to clean it.) The bikes I have worked on now start pretty well. Again, one of the best ways to keep your starter working, is not to use it excessively. Try hard to maintain your bike in a good state of tune, and with a hot battery, so that the engine lights up quickly with a minimum of starter action. Once again, it's your bike. The full responsibility for what you do to it is yours alone, but hopefully this paper will help you make some decisions on how to proceed. Good luck. Comments and corrections are always welcome.
Resources for help with starters:
Stockers Starters San Diego, California
I have talked to Stockers recently. They understand Virago starter systems and can supply you with a new or rebuilt short-shaft starter in 2 or 4 brush versions.
Cycletronics Camp Hill, Alabama
1-800 524-2252 Same as above. These people will talk to you, are good to deal with, and know Virago starters.
Joel D. Anthony Boise, Idaho 208-331-4155
$200 plus shipping.
STARTER REBUILD CHECKLIST
STARTER MOTOR Disassemble and:
* Generally clean up the components, inspect for damage or excessive wear, and run any electrical tests you think are necessary (see factory service manual)
* Smooth and clean the commutator * Measure the brushes and install new ones if needed ($25)
* Lightly re-lubricate all bearings, and reassemble (Any Moly grease)
REDUCTION GEAR ASSEMBLY
* JB weld (or otherwise secure) the planetary ring gear as described in this paper to keep it from spinning. ($5 for JB Weld)
* Re-lubricate all gears/bearings and reassemble. ($10 for Honda Moly paste)
* Test by applying 12 volts from a thick (jumper type) cables. It should spin strong and smooth If you find faults that you cannot fix, or have doubts about the overall performance of the starter, replace it with a new or rebuilt "short-shaft", four brush starter ($175-$225)
INSIDE THE SIDE COVER
Pull the side cover and:
* Remove and inspect all starter system parts ($15 for new side cover gasket) Do the following depending on the condition of the parts and what you can afford:
* Replace both clips and cut return ("compression") spring in half
* Replace idler gear #8 if it is badly rounded/chewed and/or if rubber bumper material is badly chewed or gone. Replacement here is a judgement call based on overall condition ($70)
* Replace or renew flywheel if flywheel teeth are chewed--likely to be found in the "contact section" of the teeth where the idler gear engages it each time ($150-$200 to renew, $450 new, if still available)
* Install 2mm washer fix. (Up to $20 depending on how you do it.)
* Check groove for notches where idler gear clip slides back and forth and correct (smooth out) if found.
* Clean the magnet which catches the metal particles thrown off by the gears.
* Lubricate all starter parts with motor oil as you reassemble.
* Note that you'll probably need to install a new side cover gasket. ($15)
NOTE: Cost estimates are just that. Actual prices may vary. The starter itself and the flywheel are the heavy hits if you need to renew/replace them. How far you go is a matter of what needs to be done as against what you can afford. If resources are limited obviously do all the cheap things first and try the system. Maybe you'll solve your Virago starter system problems for a while.
Figure 1 (above)
Motor to left, reduction gear assembly on right. (above)
Ring gear and moon gears on left, thin shims on right. (above)
Locked piece far left, then ring gear. Note small key in center. (above)
Ring gear and locked piece welded together. (above)
Washer sitting on idler gear #9. (above)
Washer mounted between the idler gears. (above)