Page 2 of 2 FirstFirst 12
Results 16 to 23 of 23

Thread: CBR TF125 Bucket Racer

  1. #16
    Join Date
    15th August 2011 - 12:25
    Bike
    CBR125TF
    Location
    New Plymouth
    Posts
    13
    I've been looking through Piston catalogues and it has occurred to me to ask myself why I'm trying to reinvent the wheel...

    Can anyone convince me why I shouldn't just get an oversized TS125 piston and bore the barrel to suit?
    (currently the piston to bore clearance is massive, hence my desire for new).

    Are the standard rings a bit heavy and flutter prone?
    If so, can I use a thinner ring? Is it an issue if the ring has a bit of extra clearance in the groove?

  2. #17
    Join Date
    25th March 2004 - 17:22
    Bike
    RZ496/Street Triple R/GasGas/ etc etc
    Location
    Wellington. . ok the hutt
    Posts
    17,331
    They are a bit prone to cracking the skirt. Rings bit wide. I used an mx wiseco I think, but I cheated but changing the rod which gave me more options.
    I've been told. Dreaming`s free.
    Think I'll go, back to sleep.
    Everybody listen, voices in my head
    Everybody listen, do yours say, what mine says?

  3. #18
    Join Date
    18th May 2007 - 20:23
    Bike
    RG50 and 76 Suzuki GP125 Buckets
    Location
    Auckland
    Posts
    9,901
    Quote Originally Posted by anglia4 View Post
    Is it an issue if the ring has a bit of extra clearance in the groove?
    Yes, sure is. Instead of a bit of flutter the ring has enough room to get a good swing in and hammer the top of the ring land. Eventually breaking the ring and/or land and causing all sorts of destruction. When the ring lifts off the lower ring land the gas seal is broken and hot gases squirt down the side of the piston. Overheating the piston and charring the lubricating oil. More grief and destruction.

  4. #19
    Join Date
    12th February 2004 - 10:29
    Bike
    bucket FZR/MB100
    Location
    Henderson, Waitakere
    Posts
    3,849
    Quote Originally Posted by F5 Dave View Post
    . . . a "bit" prone to cracking the skirt. . . . .
    I radiused the edges and then polished them and they still cracked every meeting. Only a little at the first meeting but by the end of the 2nd the cracks were a problem.

    Standard TS pistons are garbage and have big thick rings.

  5. #20
    Join Date
    15th August 2011 - 12:25
    Bike
    CBR125TF
    Location
    New Plymouth
    Posts
    13
    Thanks guys. Good info.

    I got my chamber about a 3rd of the way welded last night. Need to get some more argon as purging got through what was left in my bottle pretty quickly.


    I split the cases on one of my spare engines last night to figure out how it comes apart/goes together before I embark on modifying the crank in my "A" engine.
    Is there a way to get the clutch basket off as a whole assembly? Or do you need to pull all the pins/springs?
    Annoyingly the crank gear doesn't slide off past the clutch basket so I can't get the crank out without removing it.

    Its a little tempting to broach a keyway into the spacer behind the crank gear so that I can slide the crank out without removing the clutch when I put my good engine together. Especially if the balance factor takes a bit of trial and error.

  6. #21
    Join Date
    18th May 2007 - 20:23
    Bike
    RG50 and 76 Suzuki GP125 Buckets
    Location
    Auckland
    Posts
    9,901
    Quote Originally Posted by anglia4 View Post
    Is there a way to get the clutch basket off as a whole assembly? Or do you need to pull all the pins/springs?
    Annoyingly the crank gear doesn't slide off past the clutch basket so I can't get the crank out without removing it.
    You need to make some tools so life is a bit easier.

    Click image for larger version. 

Name:	20200214_105936.jpg 
Views:	13 
Size:	810.4 KB 
ID:	344662


    Quote Originally Posted by F5 Dave View Post
    Enter new spring tool. Let's see if i can reattach this. Larf you might.

    https://www.kiwibiker.co.nz/forums/a...9&d=1580702734

  7. #22
    Join Date
    15th August 2011 - 12:25
    Bike
    CBR125TF
    Location
    New Plymouth
    Posts
    13
    I did see that post on your thread... Its what I was hoping to avoid

  8. #23
    Join Date
    25th March 2004 - 17:22
    Bike
    RZ496/Street Triple R/GasGas/ etc etc
    Location
    Wellington. . ok the hutt
    Posts
    17,331
    While it is apart you might preemptively beef up the clutch it takes little extra to overwhelm it. Check my Pete's TF post for ideas though I'm not sure if I explain that I hybrid a GP basket etc onto TF gear. Skimming the steel plates to fit a 2nd extra fibre is next step if stiffer spring doesn't work.
    I've been told. Dreaming`s free.
    Think I'll go, back to sleep.
    Everybody listen, voices in my head
    Everybody listen, do yours say, what mine says?

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •