CT 90 builds

Discussion in 'Old's Cool' started by Beet, May 12, 2020.

  1. Beet

    Beet adventurer

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    877BFE85-7C28-4AA0-8A58-CED68E0E518F.jpeg Hi, I’ve looked and looked but find no specific ct90 Honda build. If someone finds another then maybe a mod can join this in.
    Anyhow. Why a ct90. Well several years or more ago now, I used to do Postie bike rides with some others in the bush just because we could. Actually started as a bit of a charity thing but that got a bit lost over the years.
    So I did these rides as the others did on CT110s, some used clone motors, some tricked up the standard motor and others built up High/low gear CTs.
    The high/low gear ones fascinated me and I wanted one. A mate heard about this and gave me all his CT left overs. Some 3 or so motors, a nearly complete ct90 high/low and various other bits. I started to sort out the nearly complete one but lost interest and it sat on a stand for some years partly parted. As time went on my mate dropped of more and more CT bits then a little while back another mate gave me several nearly complete but very rough CT90s. So with the pandemic apon us I started work on building up a high low for the grandkids to ride, adding to the pw50 and the postie with a Chinese motor in it. I put a basic frame together then did the top end up to one of the better turning over motors. I was so happy working on that motor that I felt I’d like to pull one completely apart and rebuild it. So this long winded story now comes to me doing my best to semi restore a 1978 model ct90. I say semi as it’s not to be perfect by any means just as best I can using as many parts as I have with out buying to much in or new. So I’ll add to this over time and if your doing a ct90 up then please post your progress also. I know this will fall on some deaf ears but “please keep it ct90 only”
    Thanks and regards
    #1
  2. Quiller

    Quiller n00b

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    I recently performed my first top end rebuild of any bike on my 1969 CT90, which was burning oil, steadily leaking, and had a worryingly loud timing chain rattle. It started life as a farm bike and I rode the hell out of it (and a Ct 70) after rescuing it from the barn it sat in, unridden for 20 years or so. It finally started showing signs of its age and I've taken it upon myself to get it fit for another 50 years of riding. I've learned a lot from working on it and really admire how simple it is. This is also very likely the cleanest it's been since it left the showroom floor.

    IMG_1636.JPG IMG_1650.JPG IMG_1645.JPG IMG_1647.JPG IMG_1652.JPG 90.png
    #2
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  3. R80st

    R80st Long timer

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    DSC07492.jpg DSC07496.jpg IMG_4333.jpg IMG_4334.jpg

    My CT90 KO. after 50 years on a farm. I hope to bring it back to live
    #3
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  4. Beet

    Beet adventurer

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    #4
  5. Beet

    Beet adventurer

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    Fantastic, Keep us up to date.
    #5
  6. Beet

    Beet adventurer

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    Little organising in shed plus my build so far of the 1978? Ct90 high/low. 4FF60264-CE7A-4759-9AF5-54753FE39132.jpeg A8FBA3A4-FC30-4A03-BD6F-629C5EF392A4.jpeg So I have 8 motors (1 standard 110 and 1 high/low 110, others 90s) plus 4 frames with lots of gear - possibly enough to build 2. Just loving it.
    #6
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  7. Quiller

    Quiller n00b

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    After a week of letting my new tank liner settle I've been bopping around town on the little yellow bike. Took it up a fire road near my house and to the store. It's running great, and we're no longer rattling or burning oil. Still some small leaks that I thought I had addressed, but overall it's much happier than it was. I love the looks I get riding this around; highlights of my trip to the store were a passing car rolling down it's window and shouting "**** yeah that's awesome!" and a tiny kid on a little push bike staring in awe as I putted by... IMG_1679.JPG
    #7
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  8. Ozarkroadrunner

    Ozarkroadrunner Been here awhile

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    We have a 66 which we bought from a fellow on this forum. It was a field find and the motor locked up. I have it apart and have rebuilt the wheels. But that is all I have done so far. I planned a Lifan or similar swap but now I'm thinking about rebuilding the stock motor.
    #8
  9. hugemoth

    hugemoth Big Brother is watching you!

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    bumperbike-01.jpeg

    My K0 1968 was a $75 barn find 20 some years ago. It sat in my scrap metal pile for years after the original engine toasted itself in Death Valley. Now its a mix of junk I had laying around and a Lifan 140 engine. The idea is a low maintenance bike. No battery, plastic tank so no rust, etc.. Street legal.
    #9
  10. R80st

    R80st Long timer

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    DSC07705.jpg Practising the ancient art of wheelwright.


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    The engine is all done we have to wait and see
    #10
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  11. gumpt100

    gumpt100 Adventurer

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    Hi Beet, thought you might like this. A friend of mine (in the cowboy hat in the video) runs an 8 hr endurance race series for C90's, called the Plop Enduro, some meetings there are 100 bikes on the grid!
    #11
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  12. Beet

    Beet adventurer

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    Very cool, just loved the bikes especially some of the exhausts. I’m thinking they do something like that in South Australia at Mac park in Mt. Gambier. I’ll look it up. Thanks
    #12
  13. Visian

    Visian Look out! Supporter

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    Thought I'd share my 67 CT90, which does not need a build but does need its battery charged, oil changed and a good cleaning. All original except for rectifier, spark plug cap, front fender, new tires and tubes (had to) and some NOS bits just because.

    800 miles.

    Rectifier upgrade highly recommended!

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    Old one...
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    New one...
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    #13
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  14. blaine.hale

    blaine.hale Long timer

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    Whoops, my engine fell apart! Not a ct90, but the same motor, an st90. It was missing the first gear and needed a top end rebuild anyways. Vapor honed everything, fresh seals, piston ring, and replacement first gear. Valves looked all right so I just lapped them. As soon as I get the correct paint in, I can slap this all back together in an afternoon. Such an easy and fun motor to work on.



    [​IMG]

    First gear's pawls got sheered right off and twisted the shaft as well.

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    Vapor honing on the non-painted parts

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    #14
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  15. Blackshirt

    Blackshirt Been here awhile

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    Cool thread.

    My son's first bike was a 1970 CT90 (dual range transmission). It hit the deck a few times, allowing me to have some dad time with Junior. What I learned is that "Case Yellow" (named for the bulldozer maker) is a near perfect match for yellow Posties. I found it at Tractor Supply...
    #15
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  16. lonegunm4n

    lonegunm4n Been here awhile

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    20200125_160839.jpg

    My 1970 Trail 90 (CT90K2). Mods are Radioshack rectifier, replaced front fork oil with thicker, and Dr ATV headlight. All the other wear/service items are OE Honda. I did have to replace the 'body' to the air cleaner since the PO broke it and was running it without an air filter at all, but it was worth the money to be able to run the factory air cleaner.

    I use it as my daily for around town errands since I have a company vehicle. I am fortunate to have a gas station that sells ethanol-free, so she always gets the ethanol-free.
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  17. UstaKood

    UstaKood Been here awhile

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    [​IMG]
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  18. R80st

    R80st Long timer

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    IMG_4435.jpg
    Granddaughter helping with the CT90 KO
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  19. Beet

    Beet adventurer

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    Just gorgeous. Does the rear swing or ridged? More photos or a build list.
    #19
  20. Beet

    Beet adventurer

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    Those tools on wall - I gave up, now put them in a nice long ice cream container with 0-14 and 15up. Also sockets etc. and they go on a shelf. Working for me for now.
    #20
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