108cc build

Discussion in 'Modifications' started by mark from florida, Aug 23, 2020.

  1. mark from florida

    mark from florida Active Member

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    almost afraid to ask. just got entire motor pretty much assembled. now as I install the stator and flywheel. fly wheel seems to drop down onto crank so far that it hits the case? ordered assembly for 1981 6 volt ct 70. should work with existing ignition. right? checked order form from tb says 6 volt kit. thats what I got? am I missing something?
     
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  3. kirrbby

    kirrbby Well-Known Member

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    Better post some pics and links. TB would have a 6v 3speed crank, AND a 6v 4speed.

    Links to parts.
    Pics of flywheel and stator.
     
  4. mark from florida

    mark from florida Active Member

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    Here are some pics
     

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  5. kirrbby

    kirrbby Well-Known Member

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    Your stator and flywheel is from a 81 CT70??
    I'm thinkin you might have a 3speed type crank, but need a 4speed type for the 81 stator/flywheel.

    You might have to source a early style 3speed stator/flywheel.

    Maybe @allenp42 will chime in about 81 crank/stators. Does a 81 CT use the 4speed type crank taper??
     
  6. mark from florida

    mark from florida Active Member

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    stator and flywheel are for the original 81 motor. did install a 4 speed in it though.that side of motor went together ok.
     
  7. dirtbkr188

    dirtbkr188 Active Member

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    Can you post up the TB Parts number(s) for the assembly you ordered, if you don't mind?
     
  8. kirrbby

    kirrbby Well-Known Member

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    If you still have the old crank...the one that your stator/flywheel came off of, you could compare it to your new crank.

    IMG_20141006_184434158.jpg
     
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  9. allenp42

    allenp42 Well-Known Member

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    Your stator and flywheel do appear to be correct for 80-82 CT70 Hitachi. You should see F140-67 stamped on the flywheel. This flywheel is is for a H style crank, which was used on 80 & 81 CT70s.

    I agree with Kirby. It appears that that you have a 3 speed crank in this engine. Going from memory, you should have 3-4mm of clearance between the flywheel and the stator plate.
     
  10. mark from florida

    mark from florida Active Member

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    on my order form it says tbwo622, 51 mm stroker crank for ct 70 3 speed 6 volt motor.
     
  11. mark from florida

    mark from florida Active Member

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    yes my flywheel has those numbers stamped in it.f140-67
     
  12. mark from florida

    mark from florida Active Member

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    I have thi stator from a 4 speed motor could this work
     

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  13. kirrbby

    kirrbby Well-Known Member

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    That's a bummer. It would be a very easy mistake to make, since the 80s bikes ARE 3speeds. But they are odd ducks.

    Both of your stators are made for 4speed type cranks. You need one for your 3speed crank.

    Both of yours should be more valuable than the average 3speed type...if you wanted to sell them off. I think a 77-79 CT70 stator/flywheel would be very similar to the quality of your 81 setup. But any K1-79 stator/flywheel combo should work.
     
  14. allenp42

    allenp42 Well-Known Member

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    No. You need a 3 speed flywheel and a stator from the 3 speed as well. The points height is different between a 3 speed stator plate and 4 speed and are not interchangeable.

    Top Left is a 4 speed stator plate, Top right & bottom left is a Hitachi H style flywheel (same problem as you have now), bottom right coils appear to be from a 73-78 Z50 soft tail.

    However, you can use the coils you have on your 81 stator on a 3 speed stator plate.

    Just a few examples of what you need.

    https://www.ebay.com/itm/Honda-Hita...437922&hash=item2aefa7fdba:g:UqIAAOSwTptfPJ6W

    https://www.ebay.com/itm/Honda-70-C...683110?hash=item1a9ea3c6e6:g:jaMAAOSwxuBfI1kh

    I don't have an extra flywheel at the moment but may have a plate. Will check later today and let you know.
     
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  15. mark from florida

    mark from florida Active Member

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    can i just get the flywheel and use it with my stator and plate or do i need to get everything?thanks for your help. dont really want to tear motor back apart but? poss sell some of what i have to offset cost of the right crank?
     
  16. racerx

    racerx Administrator
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    The crank & alternator are an assembly and can only used as a complete assembly. If you have a 4-speed/H-model crank, then you need the flywheel with the matching bore taper and the stator assembly that matches the flywheel.
     
  17. allenp42

    allenp42 Well-Known Member

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    Nope. You're going to need a stator plate as well. You can relocate your coils to a 3 speed plate, acquire a flywheel and you should be good to go. I would not want to tear it down either unless I was trying to end up with a 100% original show pony.

    Your Hitachi H setup is worth somewhere in the range of $125-$175 (guess). Even blank stator plates bring $20-$25ish.

    I only have one Hitachi 3 sp stator plate. It'll work fine but does have a few slice marks where the dismantler cut slots into the screws to aid removal. Did a quick search on e-Bay for stators and did not find any blank ones at the moment. Found several complete ones but they mostly on the pricey side.

    If you want this one, will send it your way $10 delivered.
     

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  18. dirtbkr188

    dirtbkr188 Active Member

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    Did you buy it directly from TB Parts or from an Authorized Dealer for TB Parts?
     
  19. mark from florida

    mark from florida Active Member

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    direct from tb
     
  20. allenp42

    allenp42 Well-Known Member

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    That is very true. There is almost difference between a 77-79 setup (3 speed crank) vs. 80-82 setup (H style) other than the taper for the flywheel.
     
  21. allenp42

    allenp42 Well-Known Member

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