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1982 Yamaha Seca xj750 starter clutch repair

Discussion in 'XJ Technical Chat' started by nothinbutjets, Jun 17, 2021.

  1. nothinbutjets

    nothinbutjets New Member

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    Alright so I am new to this website and also to the world of bikes. So I just purchased a 1982 Yamaha Seca. I got it for $100. lol I think bike man man said he got his for about the same. When I got it. It would start with the help of some starter fluid. but eventually after trying to let it idle, it would die. So it needs some good ole' fashioned TLC. Has a xj750 on it. I think an R model but not really sure on tht. Anyways, I am having the same issue as bike man man was all those years ago with the starter sounding like its not catching like its suppose to. I was asked to start a new thread so I can get help specific to my bike. So here it is. I read pretty much the entire thread all the way to the point where bike man man said that he successfully changed out the rollers and springs on his starter clutch and still I seen people say that he is full of **** and doubting that there is a way to repair without splitting the case. Im not trying to cut corners here, Im just trying to save myself some time. I like to work smarter not harder but at the end of the day, I will do what has to be done to get my bike running properly. That being said. Ive started pulling parts off to clean them up and recondition them and/replace them. carbs are off for rebuilding. it has one of those after market filter kits. those are off to be resealed since the bike has been sitting and the rubbers are seperating from the filers themselves. and then the main problem...The starter clutch apparently from all the research and videos I have scowered the web for. I have the side cover off, the stator is out, and now im trying to pull the rotor out very carefully. Im going to try this method first before pulling the motor bc if I pull the motor it will ve rebuilt and im going to go ahead and start the restoration process on the frame and tank and electrical and such. So how the heck do I get this thing out exactly? Somebody said tap on the shaft and it will pop out? how do I do this? I am just guessing by putting a bolt in there and using a hammer. Is this correct? I cant get the darn thing off. It is very frustrating. Ill post some pics when the sunlight comes out. I just want to check out the starter clutch since most of the online evidence is pointing to that being the issue. Thank You for the help in advance!

    -nothinbutjets
     
    Last edited: Jun 17, 2021
  2. Franz

    Franz Well-Known Member

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    Last edited: Jun 17, 2021
  3. Dan Gardner

    Dan Gardner Well-Known Member Premium Member

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    A few taps on the end of the shaft has worked for me. Where the rotor sits on the end of the shaft is conical, so just enough of a tap to break it loose is all it needs. It will just kind of fall off.

    I would suggest starting with a light tap, gradually getting harder until it falls off - shouldn't be anywhere near enough force to damage the shaft.
     
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  4. Franz

    Franz Well-Known Member

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    It's tightening it too much l think can damage the shaft which is why the shaft has a recess the projection on the removal tool goes into.
     
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  5. Rooster53

    Rooster53 Well-Known Member Premium Member

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    A threaded tool is supposed to be used along with an attachment to protect the shaft.

    upload_2021-6-17_14-18-1.png
     
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  6. chacal

    chacal Moderator Moderator Supporting Vendor Premium Member

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    The YM-04052 "attachment" is really just a short, solid dowel pin which prevents the end of the puller tool (YM-01080) from ever contacting the end of the shaft that the rotor rides upon, or otherwise you can/will mushroom the end of that shaft and then life becomes difficult.

    The shaft that the rotor rides on has a bit of a taper to it, as does the inside bore of the rotor itself. In essence, the rotor is locked to the shaft via a friction fit; the bolt on the end is just to make sure that it doesn't come flying off the end of the shaft and to put the final fraction of a millimeter squeeze on the rotor and force that friction-fitting to occur. When you go to remove the rotor, you're actually pulling the tapers apart from each other; it's tight but just a single mm outward draw of the rotor will release it from the shaft.
     
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  7. Polock

    Polock Well-Known Member

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    you put a dab of grease on the center of that shaft then take a "BB" and stick it in the grease, then use a regular bolt
    i think it's a 16X1.5
    tighten-tap tighten-tap then bang it's off
     
  8. Franz

    Franz Well-Known Member

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    Yup ball bearing keep the end of the bolt and alternator shaft seperate.
     
  9. chacal

    chacal Moderator Moderator Supporting Vendor Premium Member

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    It had better be a decent sized ball bearing, as the shaft is internally threaded.......that is what the retaining bolt screws INTO (the rotor puller threads into the rotor itself). So if the ball bearing isn't big enough, it will actually crush the end of the shaft and its starting threads.

    The dowel pin ("attachment") is a slender dowel pin that fits down into the bottom of the threaded rotor SHAFT (the shaft that the alternator rides upon). It bottoms out and presses against the "meat" of the shaft, at the bottom of the threaded hole, so it can't damage anything.
     
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  10. Franz

    Franz Well-Known Member

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    Len good point l didn't think of that.
     
  11. scoobydew

    scoobydew Member

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    Got the tools right here. If they have them at xj4ever.com then I recommend buying them from there. If not on there then cmsnl.com might have this part. You just stick the dowel pin into the shaft, screw in the bolt behind it until it presses the dowel and the rotor pops off. ezpz
     

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  12. chacal

    chacal Moderator Moderator Supporting Vendor Premium Member

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    Scoobydew has it exactly right, he wins a snack! And yes, we do have them available, either for purchase or rental.
     
  13. nothinbutjets

    nothinbutjets New Member

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    is number 9 some kind of neumatic guage or something? what am I missing here? No offense but those pictures are not legible enough for me to understand how this contraption works. Could you or somebody just give me some information that makes sense. maybe a video with directions. Im just trying to get the motor running correctly. Ive already rebuilt my start like recommended since the brushes were bad on it.
     
  14. Franz

    Franz Well-Known Member

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    @Rooster53 is referring to the tool shown below in the pictures in the Haynes Manual. Number 9 is a bolt M16 by 1.5 thread pitch. Len has this rotor puller tool contact him on info@xj4ever if you need it.

    16276428587591406704052549998702.jpg 16276428959299168192702910466088.jpg
     
    Last edited: Jul 30, 2021
  15. Jetfixer

    Jetfixer Well-Known Member

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    Read my post on the starter clutch ,to remove rotor get a metric 30 mm bolt thread into rotor . I have a 30mm socket and an electric impact one hit of trigger and it pops right off.. you will have to split the case . It is not as hard as I thought it would be , however I posted pictures to help . Once engine is open....DO NOT rotate crank with cam tensioner out , I did this and cams were 180 out. Now that I have done the deed for the starter clutch I could do the task much faster. There is not enough room to get the gear off of end of the clutch and get rollers and springs out and reinstall with this in the engine .
     

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    Last edited: Jul 30, 2021
  16. Rooster53

    Rooster53 Well-Known Member Premium Member

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    I see why you are asking as the pic I used the PDF copy has bleed-through from the double sided printed opposing page. You can ignore any of that lightly colored stuff, including the text that is impossible to read.

    The next page:

    upload_2021-7-30_11-46-17.png
     
    Last edited: Jul 30, 2021
  17. nothinbutjets

    nothinbutjets New Member

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    im not buying this tool kit until I understand how it works. All I see is a bunch of pieces with no explanations as to how the pieces go together.
     
  18. Franz

    Franz Well-Known Member

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    You only need the rotor tool at the moment to get the rotor off. See the photographs from the Haynes manual I posted above which explains how to do it.
     
    Last edited: Jul 30, 2021
  19. chacal

    chacal Moderator Moderator Supporting Vendor Premium Member

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    The rotor is FRICTION-FITTED onto the end of a tapered shaft....the alternator shaft is tapered on its left end, where the rotor fits onto it. The rotor hub itself is also tapered on the inside of the hub. When you install the rotor onto the shaft, the rotor retaining bolt threads into internal threads on the end of the tapered shaft.

    IMPORTANT: the alternator shaft --- which the rotor is fitted onto ----is both tapered and has internal threads.

    So, when installing the rotor --- which has a taper inside its hub --- onto the the tapered shaft, the retaining bolt....which threads into the internal threads on the rotor shaft....pulls the rotor onto the shaft, causing the tapers to meet and join and "lock" together (i.e. the friction fit mentioned previous). This friction-lock is quite robust, and truly locks the rotor to the shaft with a lot of force. Note that it is not the rotor retaining bolt that holds the rotor in place, or tight; rather, the rotor retaining bolt simply pushes the internally-tapered rotor hub onto the tapered shaft, and that is the actually locking force that holds the rotor onto the shaft. Once this lock is established, the bolt is almost just a "safety measure"----it doesn't provide the holding force. The friction lock that it helped create by forcing the tapers to interact is the holding force.

    Okay, so that explains how to install the rotor, which isn't what the discussion is about, but it helps to understand this so that the removal procedure can be better understood.

    To remove the rotor, of course you have to remove that retaining bolt, which threads into the end of the alternator shaft. The bolt comes out, but the rotor is still locked to the shaft, via the friction-fit taper lock. So how to break that lock, and get the rotor off?

    Well, you need a threaded bolt, WHICH THREADS INTO THE HUB OF THE ROTOR, NOT INTO THE INTERNAL THREADS OF THE SHAFT to "pull" the rotor off of the end of the shaft. So a bolt (the "rotor pulling tool") is threaded into the hub of the rotor, and it finally bottoms onto the end of the shaft, and further turns of the bolt pushes onto the end of the shaft, and thus "pulls" the rotor away/off of the shaft, breaking the friction lock.

    But wait, there's more!

    Since you don't actually want the end of the rotor pulling bolt to bottom onto and push directly on the end of the alternator shaft ---- that could damage the shaft ("mushroom" the end of it, ruining the taper or otherwise damaging it) ---- so you use the "attachment" tool (which is just a 40mm long dowel pin) and it fits down into the internally threaded part of the shaft, and pokes it's little dowel pinny head clear of the end of the shaft. So now.....NOW!.....the rotor pulling tool (the bolt) is pushing against the dowel pin (and not onto the end of the shaft), and pushes down onto the inside/bottom of the threaded portion of the alternator shaft, so you don't damage the internal threads nor the tapered end of the shaft.

    When it finally breaks the friction lock, it tends to make a loud pop! noise, and can be semi-forcefully ejected off the end of the shaft, so like a good Boy Scout: "be prepared".
     
    Last edited: Jul 30, 2021
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  20. nothinbutjets

    nothinbutjets New Member

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    So I finally got the rotor removal kit. Ive been putting it off for almost a year now because Ikno that im going to have to drop some dollars on this bike. I kept thinking the remover bolt was cross threading but it was really just that snug. So got an impact wrench and very slowly tapped the dowel pin and bolt in and sure enough, it popped out like butter even after its been sitting for years. 2-3 at the most as far as I kno. but ive been tinkering with it. cleaning up the carbs and trying get rid of some pitting on the chrome carb caps. So looks like ill be needing a set of those for sure. And this is as far as I got. From the part searches ive been doing online and the consensus on here, it seems like this is where the starter clutch is housed right here. So now I am taking a break and going to start reading the overhaul forum that franz recommended. Here is a pic, felt such relief when I got it out without any damage. I really thought that sucker was stuck.
     

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