Trans mounted clutch... TRX90

Discussion in 'Modifications' started by kirrbby, Nov 17, 2017.

  1. fatcaaat

    fatcaaat Well-Known Member

    Joined:
    Aug 1, 2007
    Messages:
    1,622
    Likes Received:
    125
    Instead of the button screws that hold the plate on for the oil spinner, I took the plate, and added a angled recess to it and then put flush bolts in there. I also ground off a lot of the lip that goes around it for clearance. That lip adds some regidity, but it doesn't need it...there's no pressure on that thing. So if you need clearance, you can cut that down quite a bit.

    As for your throw...there's more than one way to deal with that. You can find a thicker bearing, you can replace the throwout cage entirely and replace with a Honda Nice version (bigger and thicker bearing), you can machine a 2-3mm ring and put it in before the bearing.

    I think when I built my poor man's nice, I ended up using a honda nice cage and bearing instead of the stock trx90 one. I also once busted a honda nice one and replaced it with a TRX90 one and had the same issue with throw. I eventually replaced the cage with the Nice one.
     
    #121 fatcaaat, Jan 31, 2018
    Last edited: Jan 31, 2018
  2. kirrbby

    kirrbby Well-Known Member

    Joined:
    May 28, 2009
    Messages:
    7,969
    Likes Received:
    898
    I made up a pusher out of a 5/16" bolt, just to try the, nearly 5mm, head thickness. I think it's too much. Seems to change the leverage of the clutch arm. I'm now thinking 3mm thickness, or close, would be about right. The pusher that came with it might be ok actually.

    My cover is powder coated...I think..? How can I tell for sure?? Try blasting it??
    Anyway, it's flaking off everywhere I touch it with the screws, kickshaft, etc. What's the best way to get rid of powder coat from a clutch cover?? Cook it off in a oven?? How hot does it have to be, and for how long, to cook it completely. So I can blast it clean and paint it?? It's powdered right down into the dipstick hole, kickshaft hole, etc. And...it's a poor finish to boot.
    It'll have to go before this cover goes on for the last time.
     
  3. kirrbby

    kirrbby Well-Known Member

    Joined:
    May 28, 2009
    Messages:
    7,969
    Likes Received:
    898
    OOps...this post in progress.
     

    Attached Files:

    #123 kirrbby, Jan 31, 2018
    Last edited: Jan 31, 2018
  4. kirrbby

    kirrbby Well-Known Member

    Joined:
    May 28, 2009
    Messages:
    7,969
    Likes Received:
    898
    I opened it back up and swapped the kickshaft. I put the dratv TRX90 kickshaft kit in. The doc gives some instruction on how it should be installed, but it was kinda weird and unclear to me.
    http://dratv.com/tradkistas.html

    It comes with 2 different thrust washers. A 17mm and a 20mm. In my opinion, the 17mm needs to go on to the shaft, on top of the spiral cut gear, before you put the right side case back on. This is similar to how the CT70 setup is. The washer protects the engine case from the spiral gear, and holds the shaft in place. Then the right case goes on. Then the spring and retainer. Then the snap ring. (Dratv didn't include a snap ring in the kit.)

    The doc shows the 20mm washer going in UNDER the return spring. I don't think that's right, or necessary. It's just too big and sloppy in there, and not needed.

    This is a nice part IMO, just leave the bigger washer out, and order a new snap ring.

    The first pic is of the old shaft Thai I took out.
    IMG_20180131_191247460.jpg IMG_20180131_200553112.jpg IMG_20180131_220827856.jpg
     
  5. kirrbby

    kirrbby Well-Known Member

    Joined:
    May 28, 2009
    Messages:
    7,969
    Likes Received:
    898
    Whatever the finish on the cover is, this stuff takes it off in short order.
    IMG_20180201_173747213.jpg
     
  6. kirrbby

    kirrbby Well-Known Member

    Joined:
    May 28, 2009
    Messages:
    7,969
    Likes Received:
    898
    Easy peasy.

    My new paint doesn't look too good either tho. But hopefully it won't flake off.

    IMG_20180202_085723895.jpg
     
  7. kirrbby

    kirrbby Well-Known Member

    Joined:
    May 28, 2009
    Messages:
    7,969
    Likes Received:
    898
    Well I've gone a couple more rounds with this engine. I have it all together, kinda.

    I put the needle bearing into the clutch cover...the one that the shift shaft rides in. But when the cover was bolted down, the shift lever was binding, and wouldn't "return". Turns out the shift shaft was a little bent, so I had to replace it. Works great now, but, it has about 3.5mm of side to side play...about ⅛". A little too much I think. So I plan to pop the cover back off and put a washer or two on the end of the shaft, which should correct it easily...holding the shaft toward the left side...where it needs to be. While I'm in there I decided I should swap in 2 heavy duty springs into the clutch. 2 of 4...fatcaaat recommended that to me a while back.

    I think that should do it. Just need a bike to put it into for a test run...maybe my 93ct or zb50.
    I put the Honda monkey bike stator in it, that I modified to match the ZB or 93 stator plug. Hopefully that will work great and make this motor easy to pop into different bikes.

    I also bought another TRX90 engine from eBay. Will be a while before I get it tho. All I really needed was the left side cover and pull start bits...but the motor was cheap, and has those parts on it...in, hopefully decent, shape. I want to be able to swap the pull start on and off...or leave it on I spose. Just don't think I can use the kicker on a 3 wheeler.

    I hope to have a 3 wheeler to run this engine in eventually.



    I didn't find the race cam until a little while ago. So I'll need to install that now.

    I also need to paint the stator cover.

    Then...it will be all together...done.

    So far so good with the manual clutch kit. Hope to see how it actually works pretty quick. Right now, I'm still sayin it's a bargain for 100 bucks.

    C'mon spring :--)

    IMG_20180212_185916593.jpg IMG_20180212_185943376.jpg
     
    loopiemclooperson likes this.
  8. kirrbby

    kirrbby Well-Known Member

    Joined:
    May 28, 2009
    Messages:
    7,969
    Likes Received:
    898
    I will also have to find a foot peg setup to get out past the giant sized engine covers...this clutch cover...and a pull start on the left. The pegs will need to be around 9 feet wide. lol

    I'm thinking aftermarket ATC70 footbar...maybe with a kickstand bracket added...or maybe when it's mounted on a motorcycle, I can just lean it over on the superwide footpeg :)
     
  9. fatcaaat

    fatcaaat Well-Known Member

    Joined:
    Aug 1, 2007
    Messages:
    1,622
    Likes Received:
    125
    I see you used the trx90 stator and flywheel. Before you do anything, you need to validate the TDC and cam timing. The trx90 flywheel is stamped in a different spot for timing because the timing cover is different. If you used that mark, you will definitely be off on your static cam timing! When I did this, I went ahead and made a new mark on the flywheel once it was in the correct position.
     
    loopiemclooperson likes this.

Share This Page