Exhaust Port Bridge Crack. 5et Cylinder

Discussion in 'Fabrication, Welding, Machining' started by Jesel, Jan 11, 2015.

  1. Jesel

    Jesel Member
    Member

    Joined:
    Jul 15, 2006
    Messages:
    28
    Likes Received:
    0
    Last spring upon my routine inspection and replacements I discovered the infamous crack in the exhaust bridge of my YZ 125. This particular crack ran across the top of the bridge and followed through up between the valves. After a few calls and some research on pricing a new cylinder I went with a company that said they can weld the crack and re-plate the cylinder (other places just wanted to install a liner) with a high success rate and a 1 year warranty. When I received this back I quickly noticed that they only put a small bead on each end of the crack. I could have done that myself, minus the plating. I guess I was under the impression that they had some way of TIG welding the entire crack.

    My question is, can anybody weld the entire crack in such a tight place? My TIG at work has a fairly large head on it and there's no way I could have welded inside the exhaust port. There's always the " pre-heat, spray and pray" method with the MIG welder, but that more than likely would have resulted in a ruined cylinder. I'm not up on the advances in welding technology, I guess I just assumed they had some sort of magical, tiny TIG that allowed welding in tight places.

    What are the odds of this bridge cracking again? I only managed to get about 10 hours on this bike last summer. I will be opening up the top end again when the bike comes out of storage and before the warranty expires.
     

    - PRODUCT DEALS -




  2. jaguar

    jaguar Subscriber

    Joined:
    Jul 29, 2000
    Messages:
    1,340
    Likes Received:
    27
    I didn't know you could weld the aluminum cylinder
     
    Stop hovering to collapse... Click to collapse... Hover to expand... Click to expand...
  3. Ol'89r

    Ol'89r Super Power AssClown
    Staff Member

    Joined:
    Jan 27, 2000
    Messages:
    6,914
    Likes Received:
    28
    They do make a small tig torch and if you use a small ceramic cup and extend the tungston you should be able to reach the bridge. If not, send it to Millinum Technologys. They do it all of the time.
     
    Stop hovering to collapse... Click to collapse... Hover to expand... Click to expand...
  4. Jesel

    Jesel Member
    Member

    Joined:
    Jul 15, 2006
    Messages:
    28
    Likes Received:
    0
    We do have reduction cups I've used a few times welding stainless pipe in cramped areas with success, but as we know S.S. is in a different world from Aluminum. I think that even with a small cup with the tungsten extended out I would still be trying to weld at a near 90* angle. I don't have the cylinder next to me, but I would guesstimate the crack to be roughly 2 1/2 " long in a hole about 1-1 1/4" wide. This is a 99 yz 125 jug with the male exhaust port just to clarify.

    Every scenario I think about ends in a melted, spotty, booger welded mess. My talent kicks me in the grapes and runs out the door just thinking about attempting it.

    Millennium was regretfully the only company I didn't call. I actually had planned on doing a E.G. 144 before I got caught up in a "super sweet deal" on a '06 crf 450. It was nothing theft related, but that's a story for another time.
    I'll certainly call upon millennium should this company refuse to honor their warranty or it cracks again (wich I'm certain it will) a day after the warranty is over. Thanks for your time.
     

Share This Page