Fz1 Flywheel Stuck On Coil

[ilawrence111]

Bought new coil thing and flywheel for obvious reasons. I pulled out my stator and the flywheel is connected to the coil and won’t let go. It makes a grinding sound when I turn it. I can’t pull or pry it off from the coil and case cover. I’ve seen some threads referring to a special tool that can pull it off but idk how it works. Anyone have a video or pictures or any links on how to use it? Do the three torx bolts need to be removed? Also, are there any other tricks to removing the flywheel from the stator with readily available everyday tools? Any help is greatly appreciated.

 

[Blue Flash]

I think you are talking about the generator rotor?
You should be able to remove the case and stator while holding the rotor inside the engine.
There is a video from Copperdawg in this thread that may help.
The stator holds onto the rotor pretty tight due to the magnets...
I hope this link helps. The thread has a lot of detail up front, but scroll down to the videos.

https://www.998cc.org/threads/gen-ii-rotor-and-bearing-replacement.24255/

 

[ilawrence111]

I think you are talking about the generator rotor?
You should be able to remove the case and stator while holding the rotor inside the engine.
There is a video from Copperdawg in this thread that may help.
The stator holds onto the rotor pretty tight due to the magnets...
I hope this link helps. The thread has a lot of detail up front, but scroll down to the videos.

https://www.998cc.org/threads/gen-ii-rotor-and-bearing-replacement.24255/

i managed to remove the flywheel from the stator but it seems like it’s touching the stator and making a slight rubbing noise? Is this normal? Should there be play between the coils and flywheel?

 

[Blue Flash]

The rotor (flywheel) should not be touching the stator. There should be no contact between the two parts.
Are you seeing material loss on the rotor magnets or the stator, indicating that one or the other is scratching or grinding off the surface of the other? I would expect you would have heard a very pronounced noise when the engine was running if they were in contact. If you don't see any evidence of scraping or material loss on either the rotor or the stator, then I would think that the noise you heard was likely NOT contact between the two parts.

I know the thread that I posted up is a bit long, but run through the process I went through to get a look at what I found. I hope this helps. I heard strange noises when my bearings went south that sounded like things were scraping against each other when I started the bike. It was a very pronounced sound. Scared the heck out of me! Also, make sure that you have ALL of the parts that are shown in the photos and in the Copperdawg video. You don't want any of those parts getting lost from falling down into the crankcase. Cover that hole to the crankcase at all times the best you can.

I would carefully check out the two bearings that the rotor rides on. After you remove the rotor, the "inside" bearing is visible within the engine. it should turn easily and smoothly with your finger. If you are not certain that the bearing rotates smoothly, I would replace.it. That bearing isn't too difficult to replace. A blind bearing puller and a bearing driver like shown in the thread should do the trick, and that one is not too bad. It is pressed into the inner engine case, but not bad.
The second bearing is pressed between the outer engine case and the "bearing housing." The bearing housing is the block of metal that is pressed into the outer engine case / cover, and is also held in by the 3 screws on the outside of the engine cover, and also has three threaded holes on the inside face that the three stator screws go into to hold the stator in place.

This bearing, which I called the "outer" bearing, is more difficult to check. I stuck my pinky finger into the hold in the housing to check it, and it was locked up, but with the oil on it, it felt like it was turning fine. I put my blind bearing puller into the hole enough to grab the inner bearing race and tried to turn it. It would stick, turn a bit, stick, etc. It clearly wasn't turning then, so it had to come out.

This "outer bearing is held captive between a spacer washer on the outer engine case/cover and the "bearing housing". The housing has to be pressed out after removing the three screws that go into the outside of the engine case to the housing.
If you need to replace this bearing, buy all new screws (3 short, 3 long). I've identified the part numbers in the thread. It's a real pain in the neck to get the housing OUT without a press, but it can be done (see thread). The trick is to get the spacer, new bearing, and housing all pressed back together without the inner spacer getting out of alignment. You really need aa press for that work, and SAVE THE OLD SCREWS that held the stator in place! You need them to keep the housing aligned to the out case as it's pressed back in.

IF you are SURE that both bearings are OK and don't need to be replaced, maybe you have an issue with the spacers that are located along the length of the rotor. On the inside bearing side, there is a spacer that is tapered on one side and flat on the other. is it smooth and round? It should roll smoothly on a table top if it's not out of round. There is at least one more spacer that is inside the rotor / starter clutch assembly that may be the issue.. check them as well. I didn't see any issues there with mine, but if the rotor is not rotating smoothly, it could have also damaged the bearings. Regardless what you find, I would recommend replacing the o-ring that is installed on the inside of the tapered spacer. wet it with engine oil before putting the new o-ring back in.

 

[ilawrence111]

The rotor (flywheel) should not be touching the stator. There should be no contact between the two parts.
Are you seeing material loss on the rotor magnets or the stator, indicating that one or the other is scratching or grinding off the surface of the other? I would expect you would have heard a very pronounced noise when the engine was running if they were in contact. If you don't see any evidence of scraping or material loss on either the rotor or the stator, then I would think that the noise you heard was likely NOT contact between the two parts.

I know the thread that I posted up is a bit long, but run through the process I went through to get a look at what I found. I hope this helps. I heard strange noises when my bearings went south that sounded like things were scraping against each other when I started the bike. It was a very pronounced sound. Scared the heck out of me! Also, make sure that you have ALL of the parts that are shown in the photos and in the Copperdawg video. You don't want any of those parts getting lost from falling down into the crankcase. Cover that hole to the crankcase at all times the best you can.

I would carefully check out the two bearings that the rotor rides on. After you remove the rotor, the "inside" bearing is visible within the engine. it should turn easily and smoothly with your finger. If you are not certain that the bearing rotates smoothly, I would replace.it. That bearing isn't too difficult to replace. A blind bearing puller and a bearing driver like shown in the thread should do the trick, and that one is not too bad. It is pressed into the inner engine case, but not bad.
The second bearing is pressed between the outer engine case and the "bearing housing." The bearing housing is the block of metal that is pressed into the outer engine case / cover, and is also held in by the 3 screws on the outside of the engine cover, and also has three threaded holes on the inside face that the three stator screws go into to hold the stator in place.

This bearing, which I called the "outer" bearing, is more difficult to check. I stuck my pinky finger into the hold in the housing to check it, and it was locked up, but with the oil on it, it felt like it was turning fine. I put my blind bearing puller into the hole enough to grab the inner bearing race and tried to turn it. It would stick, turn a bit, stick, etc. It clearly wasn't turning then, so it had to come out.

This "outer bearing is held captive between a spacer washer on the outer engine case/cover and the "bearing housing". The housing has to be pressed out after removing the three screws that go into the outside of the engine case to the housing.
If you need to replace this bearing, buy all new screws (3 short, 3 long). I've identified the part numbers in the thread. It's a real pain in the neck to get the housing OUT without a press, but it can be done (see thread). The trick is to get the spacer, new bearing, and housing all pressed back together without the inner spacer getting out of alignment. You really need aa press for that work, and SAVE THE OLD SCREWS that held the stator in place! You need them to keep the housing aligned to the out case as it's pressed back in.

IF you are SURE that both bearings are OK and don't need to be replaced, maybe you have an issue with the spacers that are located along the length of the rotor. On the inside bearing side, there is a spacer that is tapered on one side and flat on the other. is it smooth and round? It should roll smoothly on a table top if it's not out of round. There is at least one more spacer that is inside the rotor / starter clutch assembly that may be the issue.. check them as well. I didn't see any issues there with mine, but if the rotor is not rotating smoothly, it could have also damaged the bearings. Regardless what you find, I would recommend replacing the o-ring that is installed on the inside of the tapered spacer. wet it with engine oil before putting the new o-ring back in.

I was able to find out that the outside bearing was bad thanks to your response. This looks a little strange though. Please let me know what you think when you get a chance.

 

[Blue Flash]

EDIT

It does look like the stator and rotor were getting together. It doesn't look really bad, but replacing both would be some serious pocket change.
I would recommend replacing both bearings while you're at it. If you change the outer bearing, the inner bearing is a piece of cake. if the one inside the engine appears to be ok, it may still be stressed from the issues caused by the outer bearing. You would have to remove the stator to actually see the outer bearing inside the housing... maybe from the outside.
It doesn't look like the rotor / stator damage is really bad... it may work fine with new bearings. It may provide peace of mind to replace them too., but that would be your call. Technically, it should work with very minor metal loss, but I don't know if the decreased metal mass would or wouldn't noticeably reduce the generator output.
Do you see any indication that the rotor shaft is bent? If it is good and straight, it should spin smoothly on new bearings. I would also replace the spacer and its o-ring (the spacer that mates up to the inner bearing) as well.
Bottom line, I would at least replace both bearings, the spacer that is inside the housing with the "outer" bearing, and also the "inside" bearing and the spacer on the "inside" bearing end, and its O-ring . If it were me, I would seriously consider also replacing the rotor and stator, just to be sure.
If it doesn't all go back together just right... even if it's just a minor "gut feeling" that something isn't exactly right, pull it back out and make sure that everything is right and no spacers are turned around backwards.

 

[ilawrence111]

EDIT

It does look like the stator and rotor were getting together. It doesn't look really bad, but replacing both would be some serious pocket change.
I would recommend replacing both bearings while you're at it. If you change the outer bearing, the inner bearing is a piece of cake. if the one inside the engine appears to be ok, it may still be stressed from the issues caused by the outer bearing. You would have to remove the stator to actually see the outer bearing inside the housing... maybe from the outside.
It doesn't look like the rotor / stator damage is really bad... it may work fine with new bearings. It may provide peace of mind to replace them too., but that would be your call. Technically, it should work with very minor metal loss, but I don't know if the decreased metal mass would or wouldn't noticeably reduce the generator output.
Do you see any indication that the rotor shaft is bent? If it is good and straight, it should spin smoothly on new bearings. I would also replace the spacer and its o-ring (the spacer that mates up to the inner bearing) as well.
Bottom line, I would at least replace both bearings, the spacer that is inside the housing with the "outer" bearing, and also the "inside" bearing and the spacer on the "inside" bearing end, and its O-ring . If it were me, I would seriously consider also replacing the rotor and stator, just to be sure.
If it doesn't all go back together just right... even if it's just a minor "gut feeling" that something isn't exactly right, pull it back out and make sure that everything is right and no spacers are turned around backwards.

Got the new stator and rotor in the mail. Do you know of any trick to remove the 3 inner torx screws to pull off the old stator? Trying to twist them out with a screwdriver or ratchet feels like I’m trying to lift Thors hammer. Not sure if I’m using the wrong sized tool or if there is red loctite or something on the threads.

 

[Blue Flash]

They do have thread locker, and they are tight. T27 Torx bit and some serious effort will get them.
Get them out and replace them, but don't throw them away! You can use them as guides for the bearing housing to keep it aligned when you press the housing back into the case.
If the screw holes don't line up after pressing it back together, you can't get the short screws back in and will have to pull it all apart again.

 

[Blue Flash]

A T27 bit and a ratchet. Press the bit in very firmly... it will want to slip.
EDIT
If you can have somebody else hold the case steady, you can apply more force to the screws without slipping.