Trail 90 wont turn over: help please!

Discussion in 'Old's Cool' started by Sidecar Jockey, Jul 17, 2014.

  1. Sidecar Jockey

    Sidecar Jockey Been here awhile

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    I recently got a 1969 trail 90. The bike is all original and complete, other than missing the air box.

    I bought the bike cheap ($150 for the bike plus a extra frame and 2 huge boxes of spare parts) because it didn't run. It had been sitting in a garage for 3 years and not moved or started. The gas tank was drained but it had oil in it.

    The kicker slipped really badly, to the point where there was no resistance on it at all. I could easily push it all the way through by hand. I took the clutch out to clean and inspect the discs and they look brand new. I put it back together and adjusted it. No more clutch slip!

    BUT... now I find that the motor is seized. Damn.

    I can stand on the kick pedal (I weigh ~155 lbs) and it wont budge. If I come down on the pedal HARD, it can get the pedal to move but the motor doesnt turn. I assume I'm forcing the clutch to slip?? Is this normal? What's going on here, am I damaging something else by forcing the kicker down and the motor doesnt turn?

    I tried to turn the motor over with the bolt that holds the stator to the crank... but its a pretty little bolt and I dont want to snap it off. No go here.

    Lastly, I tried to bump the bike to break it free... but no matter what gear I'm in it feels like neutral. I assume this is because of the auto clutch?? It feels like it shifts into N-1-2-3-4 just fine, but the back wheel turns freely in each gear. Is this normal? Is it possible to bump start a CT90? Is it supposed to 'free wheel' in every gear until you have it running and give it gas to engage the clutch?

    Thanks in advance for your help, I'm new to the CT and auto clutches!

    PS: Maybe this should go in 'battle scooters' or 'some assembly required'?? If mods feel like this is in the wrong place, feel free to move it.
    #1
  2. Sidecar Jockey

    Sidecar Jockey Been here awhile

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    If I can't get the motor un-stuck I would like to buy a new cylinder and piston. (there isn;t a good small engine / machine shop in my area that charges reasonable prices) I can do any head work myself.

    Is this a decent kit:
    http://www.scooterpartsexpress.com/...1p47fmd-honda-4-stroke-70cc-to-110cc-ct70-pit

    It seems too cheap to be good, but then again small motor parts usually are cheap. Also, by my calculation a 52mm piston would amke it ~98cc with the stocl 45.6 mm stroke... NOT 110cc as they advertise. What's with that?
    #2
  3. hugemoth

    hugemoth Long timer

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    #3
  4. Sidecar Jockey

    Sidecar Jockey Been here awhile

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    Over the last week or so, I have been spending a LOT of time on that site. I just joined today, so that I could ask my question. Thanks!
    #4
  5. MacNoob

    MacNoob piney fresh

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    dratv.com has tons of parts for these things
    #5
  6. redblk63

    redblk63 TacoDog

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    Most CT90 owners have experienced those symptoms. Cheap stuff to try first:

    The "neutral in every gear" sounds just like you have the Hi/Lo transfer lever in between the two positions. While turning the rear wheel slowly, move the lever (at bottom transfer case that surrounds the front of the drive chain) either forward (low) or toward the rear (hi). With luck, this will give you a gear.

    You say your engine is stuck? If it has been sitting a long time, try putting some penetrating oil in through the spark plug hole, and rolling down a hill in 4th gear to try and get it to turn. If no go, then you may have to open her up.

    Good luck. CT90s are lots of fun once they run!
    Larry
    #6
  7. Foot dragger

    Foot dragger singletracker

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    I was injured badly enough,and often enough,on Trail-90's as a youth that I see only carnage and pain when I look at one now.

    Who knew they werent supposed to be jumped 20' into creekbeds?
    #7
  8. Sidecar Jockey

    Sidecar Jockey Been here awhile

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    According to what I have read on various CT websites, it is normal for them to 'freewheel' in every gear with the motor off. I guess this makes sense, since the centrifugal clutch would be disengaged...

    I tried it in both high and low. When shifting the range selector I slowly rotated the rear wheel and felt a nice 'clunk' so I think it engaged. The rear wheel still spins freely though. Is there any way to check for sure if my range selector is actually engaged?

    How about bump starting? I guess you have to get them rolling fast enough to engage the clutch before letting off of the shift lever to pop it into gear??
    #8
  9. redprimo

    redprimo Been here awhile

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    Not sure what you mean by freewheel but ct90s are just like any other bike as far as rolling/not rolling while in gear. The only difference is than when you press down on the shift lever disengages the clutch and changes the gear and when you let up on the shift lever it re engages the clutch.

    To Bump start a CT you hold the gear shifter while pushing the bike and once up to speed you let up on the shifter.
    #9
  10. Sidecar Jockey

    Sidecar Jockey Been here awhile

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    Thanks for the info. I think I have a problem then...

    My bike seems to click into every gear, but I'm able to spin the back wheel with the bike on the centerstand and the motor off in every gear.

    From what you're saying, if the bike is in gear (not neutral) the back wheel should be engaged with the motor, and not spin freely? Mine isnt like that... I can easily spin the back wheel without turning the motor in any gear.
    #10
  11. Sidecar Jockey

    Sidecar Jockey Been here awhile

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    Update:

    I figured out my gear issue. The lo/hi range box was in between. When spinning the back wheel, it shifts into 'high' just fine and I can click it through all 4 gears. I know they shift because I can't turn the back wheel any more. Good!


    More BAD news:

    The 'low' range wont engage at all. If i hold the lever forward to shift into 'low' and spin the back wheel, I can feel a ratchet like little click in both the wheel and shift lever. Is there some special technique to get it to shift? What do you think is the problem wit the 'low' range?

    No wonder the guy wanted to dump this bike for $150.... everything is broken!!!
    #11
  12. ADVDucs33

    ADVDucs33 Adventurer

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    Don't fret! $150 for a 1969 trail 90 is a nice price, I too just picked one up (yellow) last weekend for the same price. My motor has verrry low compression though, but it's fixable. Between bikebandit, dratv & the fleabay, parts are dirt cheap for these. :deal

    As for your low range, mine clicks the same sound/feel as into high, no rachet clicking sounds/feel. Worst case is to just get a lifan 125 kit in it and go boondocking! (I may go this route too). Goodluck with your revival! Pics of the little 90?
    #12
  13. redprimo

    redprimo Been here awhile

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    To get it to shift into low sometimes its easier with the engine running and in gear, then you give a tiny bit of gas as you move the hi/lo selector and let of the gas as it goes in. in your case try putting out in gear and roll the bike a bit as you move the hi/lo selector..
    #13
  14. lesman

    lesman Live easy, Brake Hard

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    Take the stator cover off and trying turning over witha socket and a rachet. No move motor could be locked up. I've help a buddy who restore small honda's. I can get a CT90 motor into split cases in 45-60 minutes while taking photo's.
    You need 2 tools one to remove the stator. I can't rememer if a 12, or 13 or 14 mmmbolt will work. There is a tool for removing the clutch. Beatrice sells the tool , it makes life much easier. The are two screws on the clutch hub, try to not strip them when you try to remove them.
    Sometimes you need to gas the throttle a touch an let off to go from high to low. If the oil is so congealed and crudded up, it can prevent the clutch from "locking up"
    I've owned 2 ct 90's. They are just a hoot.
    Bike will not run without a battery.

    Good Luck,
    Les
    #14
  15. Sidecar Jockey

    Sidecar Jockey Been here awhile

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    I put the bike in grer and rolled it around while trying to shift into low. All it does is make the ratcheting click. 'High' works fine though.

    No-go with turning the motor over with the stator nut or with a strap wrench around the clutch hub. The motor is locked.

    So...

    I bought a used 1970 CT90 motor off of craigslist for $40. It turns over and feels like it has compression. It also clicks into every gear and into high/low. I'm going to swap motors this weekend. I think my 'new' used motor should be easier to get running than my locked up one. Even if this one is a dud too, I should be able to make one good motor out of the two. Plus for $40, it was worth a shot... that seemed really cheap.
    #15
  16. LashLarue

    LashLarue Been here awhile

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    It will make that noise when it is not far enough to engage. Spin the back tire and press a little higher.

    Or just wait. No one uses low except in extra ordinary circumstances. High gears, first gear is just fine for 5 mph. Low First is for 1 mph.
    #16
  17. Sidecar Jockey

    Sidecar Jockey Been here awhile

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    I took the top end off of my locked up motor this weekend and found that the rings were rusted to the cylinder. I had to use heat and drive the piston out. The good news is that the crank feels smooth and looks good.

    While my spare motor turns over freely, its low on compression. It also wont click into every gear and it sounds like there is a good bit of metal stuff rattling around in the crank case / tranny. Not good. I'm going to use this one as a parts motor, since I dont feel like splitting the cases and I think my other motor is in better shape.

    I'm going to order the 54mm big bore piston from DR ATV, and have a local machine shop fit it to the cylinder. The cylinder damage isnt too deep, so I'm sure a 4mm overbore should straighten it out.
    #17
  18. ADVDucs33

    ADVDucs33 Adventurer

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    Sounds like some nice progress on your '69! Are the valves in good shape still? I just received new tires for mine, bikebandit, tires were 26 ea, tubes 7 :) just incase you need some down the road, wayyy cheaper then fleabay.
    #18
  19. Sidecar Jockey

    Sidecar Jockey Been here awhile

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    The valves and rockers look like they are in good shape. The bike with the seized motor only has 1,600 originam miles on it, so I doubt it needs head work.

    Plus, I cant figure out how to get my normal sized valve spring compressor into this tiny head...

    The Dr ATV 53.5 mm piston is ordered. $39!! Thats the cheapest piston I have ever bought! Does anyone know what clearance to bore the cylinder to for the DR ATV pistons?? Thanks.
    #19
  20. redprimo

    redprimo Been here awhile

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    The manual calls out for .004" clearance on the stock piston. There should be specs inc kidded with the new piston and of it is forged it could call put for a tighter fit. I think I did my last 54mm CT build with a .0025" piston clearance.

    The longer duration cam that dratv sells is a nice compliment to the 54mm piston, even with the stock carb.
    #20