Help!

Discussion in 'Technical Forum' started by M87, May 24, 2012.

  1. M87

    M87 Active Member

    Joined:
    Jul 5, 2009
    Messages:
    309
    Likes Received:
    24
    Like the title says, I need help.
    First a little background here, even though I have a house in Edmonton my work means that I am spending most of my time in Victoria. This is only the third time I have been home since January, and these visits are usually for only three or four days.
    My bike has been apart since last fall because while adjusting the valves I noticed a broken spring retainer. I had all the retainers replaced by Cycle Works and had them check the head. At the same time I decided to have them split the cases and replace some transmission parts. Because there was also an issue with the cases they were also replaced.
    I did all the other work myself, that means I took the engine out of the bike and removed the head and cylinder and stripped down as much as I could until I got to the point where I needed special tools.
    Now the bad stuff. While reassembling the bike in Jan/Feb I was unable to rotate the engine by hand after installing the camshafts. I assumed I did something wrong so I left it until my next visit.
    I reassembled it again, but this time I removed the spark plugs in case it was compression I was feeling, but still had the same problem.
    This time I took pictures to be sure everything was right.
    [​IMG]
    The cranks was in the right position, I later verified that pistons 1 and 4 were at the top of the stroke.
    [​IMG]

    The exhaust cam was in the right position.
    And the intake was in the right position. At the time I counted the pins to be sure that there were the right number between exhaust and intake (28).
    [​IMG]
    Notice that the camchain doesn’t sit on the teeth perfectly, this happened when I installed the tensioner and rotated the engine a few degrees by hand.
    I removed and reinstalled the cams several times but always got the same result.
    I left town with the engine in this condition but while I was away I asked someone else to pull the cams and make sure I hadn’t put the pistons in backwards, with the intakes at the front. They pulled the head and said the pistons were right but there was some grit on a couple of pistons, evidence that the valves were contacting the head when I hand cranked the engine. They also dropped a shim inside the engine. Ooops.
    At this point I had the engine taken back to Cycle Works with the instruction to find the shim and find out what’s wrong with the cam timing.
    The engine was at Cycle Works for 4 weeks in which time they found the shim but didn’t do anything else.
    I got home from BC last night and reinstalled the cams but I am still having the same problem. When I try to rotate the engine after installing the cam chain tensioner I meet mechanical resistance and I cant turn the engine over.
    I have not put a great deal of pressure on the engine because I don’t want to bend anything but I did get up at 5:30 this morning to take more pictures and write this.
    [​IMG]
    Crank is in the right spot.
    [​IMG]
    The cams look like they are properly timed.
    [​IMG]
    Close up of intake.
    [​IMG]
    Hard to tell but the cam lobe on the intake side is pointed at about the 4 o’clock position.
    More pictures in case someone can see something wrong.
    [​IMG]
    [​IMG]
    [​IMG]
    So here is the bottom line. This weekend may be the last chance I will have to race in Edmonton this year, perhaps ever.
    Even if I do get this fixed I will still have to get the engine back in the bike and finish prepping it for the race weekend.
    If anyone knows what I am doing wrong or knows a COMPETENT mechanic who can fix this on such short notice please let me know.
    Thanks
    Mike Cormier 87 Red
     
  2. sand.man

    sand.man Well-Known Member

    Joined:
    Oct 23, 2009
    Messages:
    554
    Likes Received:
    20
    Real Name:
    Ryan M
    Where are you located right now Mike?
     
  3. YZF1000jon

    YZF1000jon Well-Known Member

    Joined:
    Jul 4, 2009
    Messages:
    658
    Likes Received:
    2
    Real Name:
    Jon Watchuk
    The camchain sitting on top of the cam sprockets does not look right. I had an issue with my yamaha when I removed the tensioner and had slack at the crank and binding of the chain on the case, putting tension back on, and "wiggling" the crank back and forth got the chain on the teeth and got rid of the binding. Just a thought.
     
  4. M87

    M87 Active Member

    Joined:
    Jul 5, 2009
    Messages:
    309
    Likes Received:
    24
    GOT IT!!!!
    If you look at the sprockets on the end of the cam shaft there are TWO sets of holes and TWO markings.
    I test fitted the cams with the lines marked "I" and "E" in the intake and exhaust positions and lo and behold the lobes where in the right positions.
    I have NEVER taken the sprockets off the camshafts so the guy before me must have done this, I just never noticed because the engine was in the frame when I took them out.
    Why there are two positions I don't know and how they were put in wrong is also a mystery to me, I just hope I didn't bend anything.
    Now I've got to get this thing back together!
    THX
     
  5. sand.man

    sand.man Well-Known Member

    Joined:
    Oct 23, 2009
    Messages:
    554
    Likes Received:
    20
    Real Name:
    Ryan M
    Do a leak down test when it's back together, borrow my gauge if you need. That will point out bent valves before showing up at the track ready to go.
     

Share This Page