Update Winter Project

Discussion in 'CT90, CT110, ST70, ST90 Discussion' started by Jan Rella, Oct 25, 2020.

  1. Jan Rella

    Jan Rella New Member

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    Hi Everyone

    New here and wanted to share what I picked up today! 1974 (or 75) ST90, 3500 miles non runner. Good compression but no spark I’m told. It’s still in my truck! I’ll keep posting and I’m sure will have a million questions!
    Thanks
    Jan in NJ 6F8464C9-76AB-4DD3-AD9C-524D875DFDED.jpeg 41D9085A-C353-4006-9840-E9AC938BAD8E.jpeg F3D4EC47-57BD-4A18-A264-FFFDB3ED295D.jpeg
     

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    Deoodles, scooter, farm dog and 2 others like this.
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  3. cjpayne

    cjpayne Well-Known Member

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    Nice find!!!
     
  4. Jan Rella

    Jan Rella New Member

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    UPDATE:

    Working thru the no spark issue. Found worn points...awaiting replacements.

    More troubling finding was 60psi compression. Shot some oil into the cylinder and still 60 psi. I opened the intake valve inspection port and everything looks good inside. I'm planning on doing a valve adjustment and checking the timing when I get the points. Will it start with only 60 psi of compression?

    It has 3600 miles on it. I changed the oil and it looked good...dark but good.

    Am I wasting my time? Should I just commence the teardown? I was going to try to get it running before starting a freshening up.

    Thanks for the input!

    Best

    Jan
     
  5. farm dog

    farm dog Member

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    I have read that a lot is lost in the hose & gauge . Don’t spray to much starter fluid in, it will wash the cylinder dry.
     
    Jan Rella likes this.
  6. Jan Rella

    Jan Rella New Member

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    Thanks Farm dog

    I changed and set the points and valves and got her running. Smokes like heck. That’s next.

    Best

    Jan
     
  7. DAX-IT!!!

    DAX-IT!!! Member

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    IMG_2877.JPG It might just be smoking a lot because it hasn't run for long, long time and because of the oil you put in the barrel. Also, there may be years of crud in the exhaust thats being burnt off.

    I bought an ST 90 that had laid in an out-house for years. I firstly changed the oil, (that smelt like parafin and ran like treacle) cleaned out the tank (as best as I could) of the caramelised petrol residue, cleaned the carb and fuel lines, freed the timing advance weights, cleaned the points, checked timing, checked/set the valve clearence gaps, put some fresh fuel in and it started - it still smoked !!! :eek:

    Check all the obvious things first, give it a run round the block and see if the smoking stops/clears before heading out on the stripping the engine down road - it might just save you a lot of unecessary grief !! :) Then you can use all that extra time saved making it look great !! ;)

    I've put a picture of mine up to give you an idea of what it was like.

    I'm now rebuilding it so will post more pics as and when. Hope you get it going and looking great :monkey: - best regards !!!
     
    #6 DAX-IT!!!, Nov 11, 2020
    Last edited: Nov 11, 2020
  8. Jan Rella

    Jan Rella New Member

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    Thanks for the reply Dax!

    I'm soaking the chamber in Marvel Mystery oil now. I'll fire it back up and see how it goes!

    Jan
     
  9. DAX-IT!!!

    DAX-IT!!! Member

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    What's Marvel Mystery Oil ??? Is it a Stan Lee invention !!! :D
     
  10. Jan Rella

    Jan Rella New Member

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  11. DAX-IT!!!

    DAX-IT!!! Member

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    I live in England so, not too familiar with the stuff you guys have over there in the States. Are you sure the oil ring is stuck ?? It would've had to have had something drastic (ran without oil or the use of incorrect oil) for that to happen :cautious:
     
  12. Jan Rella

    Jan Rella New Member

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    Dax
    I'm zero percent sure about the rings! I figured that it's been laying around so some penetrating oil won't hurt. If it doesn't clear up then it's most likely a valve job and new rings while she's opened up.
    Cheers!
    Jan
     
  13. red69

    red69 Well-Known Member

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    My S90 had some smoke for a couple of miles after 30 years being dorment. Cleared up and runs fine with no smoke now.
     
  14. Jan Rella

    Jan Rella New Member

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    Thanks Red
    I’m going to fire her back up and see what happens. Hopefully it’ll clear up.
    Jan
     
  15. Jan Rella

    Jan Rella New Member

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    Still smoking....commencing tear down!!
     

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