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Thread: Cam/ timing problem on 85 200x

  1. #1
    Join Date
    Jan 2003
    Location
    Southern MN
    --
    1,875

    Cam/ timing problem on 85 200x

    Ok I got my whole engine put back together yesterday, and it wouldnt start. It had some serious kickback, so I took it back apart. When I looked at the spark advancer, it was all chewed up, and had a grove right down the middle. There were metal shavings everywhere, and it was ruined. I have another good one I am going to install, but I wonder what caused this? I noticed the timing was off about 1 link ahead, so it was advanced slightly. Today I was trying to get it timed perfectly. When I got the timing chain off the cam sprocket, I noticed that the cam will NOT turn. Im sure this must not be good. If im correct, I remember it turining freely, right? What the heck is wrong, and what should I do? Also, should the spark advancer be lined up somehow with the "F" mark on the flywheel? Or is it all timed when you have it lined up on "T" and the cam lines up? Any advice is greatly appreciated. Thanx again.
    THE 80's RAGE! Currently owns:
    81, 85 Yamaha Tri Moto 125
    83 Yamaha Tri Moto 200 x2
    82,83 Yamaha Tri Moto 175 project
    85 Yamaha Tri Z 250
    84 Kawasaki Tecate 250
    84 Honda ATC 70
    85 Honda ATC 350X
    84 Honda ATC 250R
    (2) 84 Honda ATC 200x
    82, 83 Honda ATC 185s
    81 ATC 200
    Lots of other parts and bikes

  2. #2
    Join Date
    Oct 2002
    Location
    Minnesota
    --
    784
    Depending where the cam is in its rotation it might be trying to push the valves open which couldn't be done by hand.

    For Timing:

    take the little plug out of the side cover, align the T in the hole. Put the cam in so the little pin on the cam is at about the 10 or 11 o'clock position and so the top bolt hole on the cam is pointing to the V in the head cap. put the cam sprocket and chain on so the O on the sprocket is also pointing towards the V in the head cap. Check to make sure the T is in the hole and the 0 is towards the V, somtimes when you put it on it will rotate the motor a little. put the spark advancer thing on and tighten all bolts it should be ready to go.

    There is also a punch mark on the pulse rotor that needs to line up with a punch mark behind the timing advance plate, you might need to remove the two phillips screws to get the timing plate out of the way to see the other punch mark.

  3. #3
    Join Date
    May 2002
    --
    610
    What chewed up the spark advancer? Was there a gap between it and the pickup? When you put the cam and cam chain on, in what order did you put things together? If the chain was put on the cam before every thing was torqued the cam bushing may come of it's locating hole messing everything up. just a thought.
    Sam from Florida
    1985 BIGRED $ 200X

  4. #4
    Join Date
    Jan 2003
    Location
    Southern MN
    --
    1,875
    Sorry for bringing back a 5 day old thread. I still havent gotten this thing running. I put it together, without the CDI cover on, and I noticed that it dosent seem like the cam is spinning perfectly or somthing. When I turn it over, it goes fine, until I get to a certain point, then the spark advancer thing moves cock-eyed, and hits the little box thing that is supposed to pickup the electricity, or whatever it does. I have this thing gapped properly, and even if you gapped it as far as it would go, it would still hit. It seems almost like my cam is bent, but it cant be, because I tried another one, and the same thing happens! I know the advancer it in there right, and on that little dowl pin. It is set in the "F" position correctly. Everything seems to be correct, so what the heck it wrong? I have been struggling for many hours like this, and took it apart like 12 times and looked at everything, and it looked fine every time. I tried everything I could think of.

    I put the chain on before I had it all torqued down, I dont know if that has an effect? (like Samster said) But I could have sworn that I tried it with it all torqued down and still the same. Maybe not. Also, does that lobe hole on the end of the cam have to be facing down when you put it in? (in line with the other hole on the holder side, near the oil plug?

    Any help would be Greatly Appreciated please! Thanx again.
    THE 80's RAGE! Currently owns:
    81, 85 Yamaha Tri Moto 125
    83 Yamaha Tri Moto 200 x2
    82,83 Yamaha Tri Moto 175 project
    85 Yamaha Tri Z 250
    84 Kawasaki Tecate 250
    84 Honda ATC 70
    85 Honda ATC 350X
    84 Honda ATC 250R
    (2) 84 Honda ATC 200x
    82, 83 Honda ATC 185s
    81 ATC 200
    Lots of other parts and bikes

  5. #5
    C W. is offline First Time Rider Arm chair racerNew to the board
    Join Date
    Apr 2004
    Location
    Key Largo FL.
    --
    107

    wops!

    if you adjusted your valves with the timeing chain off a tooth you have screwd up. back off the adjusters and find true T.D.C. and start over.youl be running in no time. But take your time.

  6. #6
    Join Date
    Dec 2002
    Location
    deer park, texas
    --
    2,336
    you mentioned it going cock eyed. well one time on my 200m the bolt bent slightly. i could not get it to run and couldnt figure it out. it chewed up 2 advancers and then i saw it. i reploaced the bolt and it ran great till isold it about 2 years later

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