CT70K0 Titanic Find

Discussion in 'Projects/Builds' started by clem, Feb 19, 2019.

  1. cjpayne

    cjpayne Well-Known Member

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    Nevermind. I relooked at your pics and there never was one.
     
  2. clem

    clem New Member

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    CJ, the open/unprotected end is a good catch. It started as one of those "it'll be back together shortly" to sitting for weeks. It's inside my house so I shouldn't have to worry about bugs but dust, haha yeah we got dust!
    I heated the exhaust to try and break it free with no luck. I bought some Kroil and it's sitting now. If it does come out, I have a friend with a mill that could re-drill the stud holes. He never let's me pay him for work and for that reason, I hate to bother him with this little stuff. The tig welding will be the hardest to source out but I'm not in a huge hurry at this point. I still have to media blast and paint both engine covers and I have more stuff to buy like a seat and misc. brake hardware, sprockets, chain, etc. Keep the insight coming, I am definitely appreciating it.
    Cory
     
  3. racerx

    racerx Administrator
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    Place the old exhaust valve back in the head, then the entire exhaust port can be carefully & thoroughly glass bead blasted from the outside, in a cabinet. The valve will protect the guide & seat. Removing as much rust & crap as possible will make it easier to see what you're dealing with and allow penetrant to work more effectively. IMO, heat may help but don't expect it to make a huge difference. You'd have to heat the exhaust remnant bright cherry red (~1500-1600F) to soften it...and most likely ruin the casting in the process.

    If you can access the collar via the notch, try drilling a hole...then inserting a punch, that can be hammered. It's the impact loading that'll break the rust bond...which is tough, but brittle.

    A slide hammer could make quick work of this. However, that's getting a bit too specialized for most.
     
  4. clem

    clem New Member

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    I like the idea of drilling a hole in it to gain the extra bite. I may even be able to use the punch to get it to spin apart inside exhaust outlet. The wife just put a pot of coffee on to go with a little king cake so I'll have to let it sit a while longer. ;)
    I did manage to remove the balls and springs from the footrest. One battle won today, if I could get two under my belt in one day, watchout!
     
  5. wanrep

    wanrep Active Member

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    So that's your secret. Here I've been having beer and pretzels on Saturday afternoon. Need more cake.
     
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  6. Tripod

    Tripod Active Member

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    Thats kind of how it goes with these bikes when youre battling rust and the unknown...
     
  7. clem

    clem New Member

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    We I've had no luck in removing the exhaust flange from the head. My friend who has the mill also has a head that he is willing to sell me so I am going to buy that. The only difference that I can see from pics is that it has a different casting number on it from what I have. I cannot find any definitive information on what these castings mean other than E22 is chinese. My head has E10 on it while the one offered up has E9. The inlets are both around 22mm and it's just as dirty as the one I pulled off of my bike so it should match up well.:LOL:

    I was able to find a K0 seat also so I'm pumped about that!
     
  8. clem

    clem New Member

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    I had to purchase a new seat hinge and bolt for this CT. One thing that I have noticed is that the bolt does not fit correctly in the bracket. There is a gap between the hex head and seat bracket. I am wondering if this is a byproduct of the hinge or bolt. Can someone give me measurements on the bracket width? Thanks
     

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  9. wanrep

    wanrep Active Member

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    The seat bracket is approx. 85mm wide. The bolt is 94mm long. (not counting the head)
     
  10. clem

    clem New Member

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    My seat bracket is the same but the bolt is 98mm not counting the head. The stepped part is 97mm which is too long and that's what's causing it to stick out. This is an OEM bolt, so I figured it would be correct. Thanks for the measurement.
     

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  11. racerx

    racerx Administrator
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    AFAIK, there's only one seat hinge bolt and it fits all years. Adding a lockwasher & flat washer to the M6 end should take up the slack. Nothing wrong with adding a flat washer to the M8 side, if need be. Re-machining the bolt would be more cumbersome and for very little effect.
     
  12. clem

    clem New Member

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    I got a replacement head for the 70. What do you guys think about the condition of the combustion chamber? Valves will be replaced 20190311_191050.jpg
     

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  13. OLD CT

    OLD CT Well-Known Member

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    Need a close up of the seats once you pull the valves.
     
  14. clem

    clem New Member

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    Ten fo. Will try tomorrow night.
     
  15. clem

    clem New Member

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    20190313_200514.jpg
    I got one valve out and found pitting. I'm not having any luck with this at all. I'm very close to just buying a china head and calling it a day. This is starting to suck.
     
  16. OLD CT

    OLD CT Well-Known Member

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    Yes that's Effed. I would look for a real Honda head as the china heads have the new dome and you would need the correct piston to match it. It will really cheapen all the quality work you put into the machine thus far.
    The bike may have lower compression with the chi-com head and not hit 42 mph or so. It looks great in red BTW. Dratv has a E22 head on ebay for 130 shipped. If I had to buy aftermarket this is probably the best route. All the other used heads seem like problems or way overpriced on ebay.
     
    #36 OLD CT, Mar 13, 2019
    Last edited: Mar 13, 2019
  17. clem

    clem New Member

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    Yep, I just scrolled through ebay and each one looks like a crapshoot. How expensive of a crapshoot I make it is the question.
    I have managed to collect 3 junk heads in the process. I bought this last one from a friend so I'll get my money back.
     
  18. racerx

    racerx Administrator
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    I tend toward over-optimism...usually. This head casting looks really bad. If it were mine, I'd glass bead blast it then hit the valve seats with a 45-degree cutter...working slowly, looking for any signs that might possibly be enough solid metal remaining to recut valve seats. Good, crisp, detail shots like yours can sometimes make things look rougher than they are but, in this case, I don't think so. Since you don't have a blast cabinet and cutting stones, you'd have to farm this out, a ~$100 gamble on what looks like longshot at best. Seriously, your original head casting is far more solid, structurally & mechanically. With that one, IMO, it's a question of how much money it would take to fix...not "IF" it can be brought back to life. So, it comes down to your priorities...originality vs fresh reproduction parts.
     
  19. clem

    clem New Member

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    Racerx, I did have a blast cabinet at one time but put it to the road to make room for other things. I use a small blasting gun and bucket with a blasting hood out back. I usually blast in a plastic bin to catch most of the bead and re-use until it is too far gone to be effective. Over the last 5 or so years I have been restoring motorcycles, mainly vintage two strokes but I am at the point where I want to keep the wallet closed for a while and enjoy riding them. The CT is a project that I picked up a few years back and have done stuff here and there on it to fill in between other restorations.
    The valve cutting part is what throws me off here. I don't have the tools to do it myself and don't know of any shops locally that I would/could trust to do it correctly. I am assuming that is probably not worth acquiring tools to do this one job for me but I may be off on that.
    When I return this head I am going to bring my original with me to try and convince him to put it on his lathe and cut out the exhaust remnant, maybe this head can be salvaged. I'm sure that he can get the one stud out which would leave welding/filling in the trashed stud hole and re-tapping. We'll see what comes up in the interim, I'm not giving up!
     
  20. clem

    clem New Member

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    Well,I have something positive today. I got the seat in today and it is as nice as was advertised. It is an original pan with new foam and new seat cover. 20190314_181427.jpg 20190314_181500.jpg
     

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