Rebuilding your starter  \ Replacing the starter seal

This is a basic instruction page on pulling your starter to replace the starter seal, this project assumes that you are somewhat familiar with your bike, basic hand tools and have the desire to do it yourself.

Step one is to first disconnect the battery at the negative terminal, this is an important safety precaution so please do not omit this step.

Step two will be to drain your engine oil, the starter sits below the engine oil level and you will have a large puddle in your driveway if you do not do this first. now is really a good time to get that oil change done anyway.

Step three is to remove the starter. this is a pretty straight forward operation, first remove the starter lead with a 10mm wrench. next remove the 2 bolts that hold the starter in place like so:

Once you've removed the bolts, the starter will slide out towards the right hand side of the bike. It's held in by an o-ring. if it doesn't slide out easily, you can try using a prybar or large screwdriver. alternatively a light tap with a piece of wood and a rubber mallet should get things loosened up and moving out. Once you get the starter out of the bike and onto the bench we can get started ;o)  on rebuilding the unit    .One thing to take note of with the unit intact before dissasembling would be to maybe make a mark along the side of the starter unit. This can help getting all the pieces back together the same way once you've finished.  The starter pieces are actually keyed but marking it will help you get it back together easier.

Once you've got the screws out, you can carefully pull the pieces apart. try to keep things in order and remember the way they came apart.

 As it turned out we were lucky in that the seal was not leaky and there was no oil in the starter. If you do find that your starter has been soaked, get yourself a can of CRC brake parts cleaner and some rags and give everything a good cleaning.

In order to get to the seal, you'll need to disassemble the gear assembly or nose-cone. a pair of snapring pliers is what you'll need to get it apart. I believe you can pick up a cheap pair at your local autoparts store or better yet if you don't own a pair, call up your auto mechanic buddy and borrow them.

After you take the snapring off, you can then slide the starter drive gear off of the end of the nosecone, this will expose yet another snapring underneath which holds the starter output shaft in place in the bearing. Now is a good time to spin the output shaft and check that the bearing moves freely without any binding or noise.

Go ahead and remove the second snapring keeping an eye on how it is clipped into the groove. most snaprings have a sharpedged side and a more rounded edge side. the side with the sharp edge side should be facing up as in the picture. This is the retaining side.

Once you've got the 2nd snapring out you can remove the output shaft from the starter nosecone. If it doesn't slide out easily, a slight tap with a block of wood or rubber mallet should get it to come out. I suggest you remove the 2 small planetary gears first marking which way they came off so that they don't go flying off under the bench or something.      Ok, we've finally gotten to that pesky seal. get a medium or large screwdriver and pry under the seal to remove it. Once you've got it out, now would be the time to clean up and remove all the old grease. 

Once you've cleaned everything up, get your new seal and lube the inner diameter with some grease. I like to use high-temp wheelbearing grease for jobs like this, it's tough, thick and tends to stay put. I've also packed the starter bearing with grease as well. Next, using a  * SMALL * light hammer and either the old seal or something like a  1in. socket, carefully tap the new seal in place. When you are done the top of the seal should be flush with the housing with the numbers facing up towards you..

Now you can reassemble the output shaft into the nosecone housing, lightly grease everything as it goes back together, you don't have to overdo it but I like to make sure everything is well lubed.

install your small snapring onto the shaft, once you've got the shaft all the way into the housing and the snapring groove is visible from the top side. next reinstall the output gear as shown and finally install the larger snapring. at this point you should find that the assembly spins smoothly and easily. if that is not the case, stop now and go back over your assembly to find out what is wrong.

Ok, the unit looks good, no obvious marks on the outside, no visible signs of shorting or binding.  lets get some emery cloth and clean up the brush surface just a bit. If while your examining the commutator you see that there is a lot of wear on the brush end, or signs of grinding or burning then you are going to need to have the commutator repaired\replaced. A local electric motor repair shop should be able to do this for you.

While I didn't follow the order in exactly this way, you can see the result. just lightly clean up the commutator brush end surface to assure good contact.

Ok, lets get a look at those brushes. these brushes have some wear and probably should be replaced soon. there is still enough meat on them to probably get through another season and they otherwise look fine. If there is any question at all when your doing your starter, by all means put a new set of brushes in while it is apart. I won't be replacing mine this time.

The next step is to get a q-tip or rag and clean out all the old grease from the bushing and put some fresh grease in there. Do not pack it full of grease because you will have problems getting it back together.

ok, lets get all the parts ready for reassembly, we've cleaned and put some fresh lube on the planetary gear set.  If you never heard the term planetary gear, its a way for getting gear reduction or torque multiplication in a very small space. Here, the planetary's revolve around the outer ring gear to achieve higher torque without adding much to the actual size of the starter.

In any case, you'll want to put plenty of grease in and around the planetary gears because there is quite a bit of load on them.

Go ahead and start assembling the pieces, starting with the commutator and housing.  oh yeah one word about the o-rings, I found mine were in terrible shape so I hustled down to my local hardware store to peruse their assortment of square cut o-rings. I found a couple that would do the trick and back I shuffled. I did find a couple that didn't and after a bit of trial and error I was back in business. you may want to try and order these from Yamaha if they are available. These days I pretty much assume nothing made of rubber is going to be available and make other plans. One tip I did find out was that you can be a bit smaller on the o-rings and they will work out ok. Ideally you'd be looking for square cut o-rings of about 2 5\8" in diameter. I found some @ 2 1\2 and they worked well.. 

now is a good time to clean up those assembly bolts, wire brush and clean them, I recommend using a good antisieze compound when putting them back together to prevent problems if you have to pull it out sometime in the future.  Finally install the brush end, making sure that the brushes are making good contact with the commutator brush end, this will probably mean pushing against the brushes as you install the end cap. I found it easiest to kind of hold the end at an angle and push it sideways while sliding it on. Spin the end around till you get it lined back up in the notch and hopefully the marks you made earlier. Install the bolts and tighen them slowly and evenly until they are snug. make sure everything is lined up and tighten them up a bit more. What I found is that you do not want to over tighten these bolts as they tend to push the o-rings out of their slots.