//ArrowChat Code

Upcoming Events for the Next 120 Day(s)

Results 1 to 15 of 15

Thread: Possible to repair Tri Z crank?

  1. #1
    Join Date
    Jan 2013
    Location
    Hartlepool UK
    --
    148

    Possible to repair Tri Z crank?

    Any one had good results getting similar to this repaired?

    Click image for larger version. 

Name:	triz crank.1.jpg 
Views:	32 
Size:	979.9 KB 
ID:	256678

    How was it done?

    I was thinking of TIG braze then turning back down to correct diameter.
    Attached Thumbnails Attached Thumbnails triz crank.2.jpg  

  2. #2
    Join Date
    Mar 2010
    Location
    Slidell, LA
    --
    4,473
    What are we looking at? Are those gouges where the stator side seal rides? Can’t really tell.
    Feedback for yaegerb: Click Here

    Need something blasted or polished or both? Send me a PM

  3. #3
    Join Date
    Jan 2013
    Location
    Hartlepool UK
    --
    148
    Yeah,

    it's off an engine I picked up that had been sat without a stator cover on and corrosion has gotten into the crank on the area around the crank seal.

    Decent cranks are thin on the ground and all available seem to be suffering from the same. I have three like this

  4. #4
    Join Date
    Jul 2005
    Location
    Manheim PA 17545
    --
    4,875
    Why not buy a new one that's tri. Yz250 is the same.
    2005 KFX700
    2001 Blaster
    2015 Rancher 420 dct eps irs

    Coal Country Rider

  5. #5
    3Z with Fangs! is offline At The Back Of The Pack Arm chair racerFirst time rider
    Join Date
    May 2018
    Location
    Virginia
    --
    188
    Actually I don't believe YZ250 Is the same. The flywheel taper is different. You can use it but with the YZ Flywheel and stator, you'd also lose lights going this route.

  6. #6
    Join Date
    Mar 2010
    Location
    Slidell, LA
    --
    4,473
    Quote Originally Posted by poolieZerUK View Post
    Yeah,

    it's off an engine I picked up that had been sat without a stator cover on and corrosion has gotten into the crank on the area around the crank seal.

    Decent cranks are thin on the ground and all available seem to be suffering from the same. I have three like this
    I am pretty sure you could get that tig welded. There’s really only one place I know that could fix that appropriately but it’s in the States and may cost a lot for shipping. I would try crank works in Arizona.
    Feedback for yaegerb: Click Here

    Need something blasted or polished or both? Send me a PM

  7. #7
    Join Date
    Feb 2015
    Location
    Cairo NY
    --
    24
    Is it heat treated-hardened? I'd be hesitant to weld on it for fear of warping. My inclination would be to turn the bad area down and shrink a sleeve on. Of course, you want to be sure the crank is true before cutting! I also suspect there is a center hole inside the crank cheek, which would guarantee accuracy. So if rebuilding the big end, fix the seal surface before assembling.

  8. #8
    Join Date
    Oct 2002
    Location
    Northeast
    --
    16,884
    I had a couple RM125/250 cranks TIG welded when I was in my twenties, both had wear spots where the oil/water/seal had been riding on.

    Guy fixed them in about 45 seconds and I ran them for a few years before I moved onto bigger bikes and trikes.

    Shouldn't be a big deal...
    WHO IS Q?? WWG1WGA!!


    86 ATC200X Flatrack ( I may not be fast but this is one FAST 200X!!

    86 ATC350X Motocross, 86 ATC452X Flatrack!!

    07 Weekend Warrior Toy Hauler

  9. #9
    Join Date
    Apr 2011
    Location
    Mexico
    --
    7,498
    You can weld that and get it turned, MIG, TIG, stick, whatever, but use steel, donít braze it! Brass is soft. Best done with the crank pulled apart. If cost is no object and you want the best, send it to Falicon and get it balanced at the same time, but any competent custom machine shop should be able to build up the shaft and turn it to size.
    Nico Suave.... be part of something bigger

  10. #10
    Join Date
    Mar 2010
    Location
    Slidell, LA
    --
    4,473
    Quote Originally Posted by oldskool83 View Post
    Why not buy a new one that's tri. Yz250 is the same.
    It is not the same
    Feedback for yaegerb: Click Here

    Need something blasted or polished or both? Send me a PM

  11. #11
    Join Date
    Apr 2011
    Location
    Mexico
    --
    7,498
    RH side is the same as YZ, but the LH side used a different diameter. If he was willing to give up his lights and could find a YZ ignition to go with a YZ crank then I believe it would be an option.
    Nico Suave.... be part of something bigger

  12. #12
    Join Date
    Jul 2018
    Location
    TN
    --
    748
    I've seen it done. Not a Yamaha, but small crank nonetheless. The welder REALLY needs to KNOW what he's doing. Not some green horn.

    I watched an old guy fix one in a machine shop I worked in years ago. The crank was first turned undersize. Then, Tig weld, Air hardening tool steel rod & it was done mostly submerged in a pan of water. Left to cool slowly and then set up on an ID/OD grinder to finish.

    Can it be done? Yes, absolutely. Easily....No.
    Amateur Resurrectionist

  13. #13
    Join Date
    Jan 2013
    Location
    Hartlepool UK
    --
    148
    Same boat for YZ cranks in terms of wear and availability. Not sure whether the YZ cranks are available new but tbh haven't looked though wouldn't have thought so.

    No bottom end power with reduced flywheel mass and loss of lighting coil unless you use sought after aftermarket road legal ignition/lighting stator.

    The reason I thought about braze was because I have some rods and a machine I know Mig is tough material to work so in hindsight probably better than braze for friction area.

    As for being toughened I put an old file across damaged area and it dug in fairly easily now I'm a carpenter not an engineer so don't know how that compares to the Rockwell scale if it's a useful indicator at all.

  14. #14
    Join Date
    Feb 2015
    Location
    Cairo NY
    --
    24
    If you can cut it with a file, it is plenty soft to machine. After looking at the pictures again, I would be tempted to emery cloth it, and see if a new seal will touch all around. May not need more than that!

  15. #15
    fabiodriven's Avatar
    fabiodriven is offline Aspiring romance novel cover model, and the Official 3WW slayer of thieves and swindlers. Catch me if you can
    Join Date
    Jun 2008
    Location
    East Bridgewater, MA
    --
    10,069
    Quote Originally Posted by ponderinjunkman View Post
    If you can cut it with a file, it is plenty soft to machine. After looking at the pictures again, I would be tempted to emery cloth it, and see if a new seal will touch all around. May not need more than that!
    I just looked again because this was said, and I agree. You don't have anything to lose by trying. It looks like it might be OK.
    85 Tri-Zinger 60
    85 ATC250SX
    86 ATC250SX
    87 ATC250SX
    02 XR650L conversion
    84 ATC 480R

//ArrowChat Integreation Code //