1971 TS90 Project!

Discussion in '2 smokers' started by whitham_wannabe, Apr 16, 2012.

  1. whitham_wannabe

    whitham_wannabe Long timer

    Joined:
    Feb 26, 2008
    Oddometer:
    1,131
    Location:
    Mukilteo, WA
    Bring on the tiddlers! Just picked this TS90 up from an inmate, for the princely sum of $150, in need of some work, but oh so cool!!

    [​IMG]

    The bike came non functioning, with a siezed up kick starter and siezed up brakes, but with a spare motor and spare brand new tyres. When I got it home, I couldn't get the motor to turn over at all, even by bumping the back wheel, so figuring the original motor was going to need to come out, got to work.

    [​IMG]

    Curiously, with the motor on the bench, the kickstarter would now turn the motor over, though the shaft is now upside down, so has no return spring action. The motor would now also turn over with the sprocket, so my initial fears of a locked up transmission were allayed somewhat.

    What to do next ... the PO said he had tried the spare motor, but that it wasn't very strong. It did, however, look in better shape than the original. A quick compression check showed that it had about half the compression that the original has. Pulled the head and barrel, and found out why ...

    [​IMG]
    [​IMG]

    Ooops ... so the question now is where did the rest of the skirt go?! Peering down into the crank, I really can't see any shrapnel down there, so I am wondering whether to swap the piston and cylinder from the original onto the spare bottom end, or whether to split both cases and fix the kick starter mechanism in the old motor.

    Any opinions?
    #1
  2. Valleyrider

    Valleyrider I Survived The '60s

    Joined:
    Apr 12, 2007
    Oddometer:
    1,891
    Location:
    Idaho Panhandler
    The engine in the frame in your first photo is a "TC" (dual range transmission).
    You're a good man for taking this POS of the PO's hands.
    From what you've posted, I would suspect the missing piston skirt was removed by the PO and the top end put back together about the time he put it up for sale.
    With what you have found so far, I would be thinking about splitting this cases "IF" you plan on keeping the bike. It appears to be in good shape cosmetically...?? with the exception of the seat cover.
    #2
  3. Brunow - 007

    Brunow - 007 Bantam Fever

    Joined:
    Oct 26, 2009
    Oddometer:
    313
    Now that's a very nice bike! Good luck with it!
    #3
  4. bondbmw

    bondbmw Adventurer

    Joined:
    Apr 22, 2009
    Oddometer:
    60
    Location:
    San Diego
    90cc hack Ropey?
    #4
  5. Tuff Tunica

    Tuff Tunica Moto-Skiveez creator

    Joined:
    Sep 9, 2005
    Oddometer:
    873
    Location:
    Park City, UT
    I got nearly an identical bike last year. Mine is a 1970 TC90 . A little better shape than yours.

    I'll be watching your progress. I have some specific questions about the way the rotor works for the equivalent of reeds for the two stroke. Wondering if this is a common wear/replace item?

    Good luck! :ear
    #5
  6. Shocktower

    Shocktower Long timer

    Joined:
    Jul 27, 2009
    Oddometer:
    9,535
    Location:
    Oregon City Orygun


    Very nice and POS means Pretty Ols Suzuki :evil
    #6
  7. MightyChosen1

    MightyChosen1 I wanna be sedated

    Joined:
    Sep 17, 2008
    Oddometer:
    1,580
    Location:
    Central,IL
    There is a running one here in central Illinois for $175. I called offering to buy it if it had a title but I did not hear back so I guess the answer is no. I thought it would be perfect for my next project, some sort of small displacement cafe bike.


    http://peoria.craigslist.org/mcy/2978561049.html
    #7
  8. Gham

    Gham Long timer

    Joined:
    Mar 1, 2005
    Oddometer:
    1,669
    Location:
    Auburn Hills,MI.
    aaahhhh........my first love,a 1971 TC90,I burnt holes in 8 pistons before I learned about jetting and air filters.I could swap out a top end in 30 minutes! Of course at 15 years old I didn't think about metal in the crankcase or scarring the cylinder.Ignorence is bliss sometimes:rofl
    #8
  9. Gham

    Gham Long timer

    Joined:
    Mar 1, 2005
    Oddometer:
    1,669
    Location:
    Auburn Hills,MI.
    [​IMG]


    Not mine/but identical to it
    #9
  10. Red0ktober

    Red0ktober Adventurer

    Joined:
    Apr 19, 2012
    Oddometer:
    58
    Location:
    Hood River, OR
    I've also come to have some little Suzuki TCs. I have my dad's old '69 TC120 that I'd like to get running again (I took it apart when I was a kid). I bought another TC120 for the parts to replace the ones I probably lost years and years ago, and with it I got a complete TC90.

    I've been running the TC90 around my yard, but it's running weak, especially on the upper range of the throttle. I need to pull the carb and check the jets and settings. [edit: spark arrestor was clogged, running strong now!]

    I'll try to start the parts bike when I get the tank cleaned up a bit and a new fuel filter, hopefully Monday. If all is well, I'll swap the good bits over to my dad's bike (parts bike doesn't have a title).
    #10
  11. kurtdaniel

    kurtdaniel n00b

    Joined:
    Jul 10, 2012
    Oddometer:
    5
    wow,, really nice find for that price.. i love that kind of bike.. I just found this Motorcycle parts bargain that id go to if ever i have a bike like this to modify..
    #11
  12. Red0ktober

    Red0ktober Adventurer

    Joined:
    Apr 19, 2012
    Oddometer:
    58
    Location:
    Hood River, OR
    The insurance premium for my '71 TC90R is less than the multi-vehicle discount it gives me, so my insurance went DOWN by $47 over the year!
    #12
  13. Bud Tugly

    Bud Tugly Gnarly old curmudgeon

    Joined:
    Feb 14, 2007
    Oddometer:
    256
    Location:
    Formerly Ishpeming, MI now Eugene, OR
    A fun little bike for playing in the woods or running around town. They were Suzuki's answer to the Honda Trail 90, but had better suspension (for the day) and more power. That dual range transmission makes it able to climb anything you can get traction on.
    #13
  14. Red0ktober

    Red0ktober Adventurer

    Joined:
    Apr 19, 2012
    Oddometer:
    58
    Location:
    Hood River, OR
    They only put a 3-speed D/R in the TC120 though, with an odd shift pattern - neutral at the top and all three gears down.

    Still waiting on new petcocks to get the TC120s running. Just rode the TC90 to the hardware store on my lunch break.

    I'm going to fix a few more things then put the TC90 up for sale, maybe upgrade to a KLR650. ;)
    #14
  15. YamaGeek

    YamaGeek Ancient trailbike padwan

    Joined:
    Jun 24, 2007
    Oddometer:
    8,218
    Location:
    western oregon
    Honda Trail 90's, and the old Yamaha snorkel cased 80's and 100's had neutral at the top, not that odd at all if you've ridden them for years. I actually prefer it to having it hide between first and second.

    The TS 90 was a sweet little bike for it's time, and a good performer. One way to gain a few small ponies without changing the bore or carburetor, at least for the iron cylindered ones, is to polish out the roughness in the transfer ports, and have a machine shop take a few thousanths off the head. You will have to richen it a smidge on the main jet. Mine ran so great a friend's felonous stepson stole it from me.

    Rat bastard..:huh
    #15
  16. Nailhead

    Nailhead Free at last!

    Joined:
    Apr 6, 2003
    Oddometer:
    7,029
    Location:
    Longmont, CO
    So did the Minitrail I had.

    That pattern made so much sense and became so ingrained that I just walked away from the TM 75 my dad was trying to teach me to ride because I refused to put up with what I thought was a stupid shift pattern. I think I gave it all of about 2 minutes before I got fed up.
    #16
  17. vtwin

    vtwin Air cooled runnin' mon

    Joined:
    Jan 11, 2005
    Oddometer:
    8,008
    Location:
    NorCal

    My Suzuki K11p with an 80cc has a 4 speed with neutral at the top.
    #17