Results 1 to 8 of 8

Thread: GPX 250 Cam chain

  1. #1
    Join Date
    12th June 2004 - 23:15
    Bike
    ..
    Location
    ..
    Posts
    2,797

    Question GPX 250 Cam chain

    Hi ppl. We are about to do the cam chain on my son's 1988 GPX 250. Manual on the way. Anything we need to know that is out of the ordinary or will make the job quicker and stop us doing something that makes work later?
    Also should we us an endless chain or just pull a new chain in and us a joiner? Then retime etc?
    Thanks

  2. #2
    Join Date
    13th January 2004 - 11:00
    Bike
    Honda PC800
    Location
    Henderson -auckland
    Posts
    14,163
    Open petrol cap ---pull grenade out of pocket -remove pin -insert granade in petrol tank--step briskly away from bike
    Ok thats the dissasembily taken care of......
    Tensioner can be a sod it seems to take 3 hands to retract it
    I'd do the split link thing to be sure.
    Otherwise as i recall pretty straightforward.
    Dumb question--are ya sure the chain is Knackered -Have ya tried giving the tensioner a little"nudge" to be sure its fully extended
    If its any help the GPX and GPX motors are basicly the same
    To see a life newly created.To watch it grow and prosper. Isn't that the greatest gift a human being can be given?

  3. #3
    Join Date
    12th June 2004 - 23:15
    Bike
    ..
    Location
    ..
    Posts
    2,797
    Quote Originally Posted by FROSTY
    Open petrol cap ---pull grenade out of pocket -remove pin -insert granade in petrol tank--step briskly away from bike
    Ok thats the dissasembily taken care of......
    Tensioner can be a sod it seems to take 3 hands to retract it
    I'd do the split link thing to be sure.
    Otherwise as i recall pretty straightforward.
    Dumb question--are ya sure the chain is Knackered -Have ya tried giving the tensioner a little"nudge" to be sure its fully extended
    If its any help the GPX and GPX motors are basicly the same
    Hi Frosty
    Thanks for the reply. If you dropped anything other than petrol in to a GPX fuel tank it would fall apart.:slap: All the early ones have rust.

    Yep we took that out last night and had a good play with it. I lengthen the ones on the Yamaha AG 200. I add about 10mm and they last for ever but the boy is not wanting to do that and would rather replace. He is not wanting the chain to peal the alloy off the cast should it touch it and stuff everything else.
    I assume you mean the GPX and the GPZ motor....? Thanks for the help. See you in Taupo.

  4. #4
    Join Date
    12th June 2004 - 23:15
    Bike
    ..
    Location
    ..
    Posts
    2,797
    The tensioner is easy to work with. You undo the grub screw in the top of them when they are out. Put the long spring in the top. compress the long spring and the steel insert. Screw the grub screw back in and it holds the tensioner. Replace the unit in to the motor and then undo the grub screw. It lets the Tensioner go. Then screw the grub screw back in to stop oil leak. Very clever really.

  5. #5
    Join Date
    10th June 2005 - 19:24
    Bike
    KTM 250exc
    Location
    Napier
    Posts
    1,814

    Well was working with dad (G4E) on the GPX tonight and have sucessfully finished the job. we had no worries all up and the 'riveting' of the new chain went well. The new chain has turned it into a brand new machine. It used to make tapping and knocking sounds that could be heard even with the helmet on at 50k's through town but now its smooth runnings.

    Was a bit worried after assembly had been finished because she just wouldn't fire. after nearly killing the battery through repetative cranking it was decided to push it down the bloody great hill we live on, which shortly after beginning it fired into life.

    Cheers for the advice guys and hope to see some of you at taupo

    Now to go ahem 'wear out' the old tire so i can slap the new rubber on ...

  6. #6
    Join Date
    1st April 2005 - 16:59
    Bike
    2004 krr zx150
    Location
    CHCH
    Posts
    480
    Just out of intrest as someone who intends on doing the chain in his zxr250 this week (I keep forgetting to order the thing though ), how easy was the riviting? Did you already have the correct tool or did you have to go buy it?

    (I sense that the riviting will be the big issue for me, not having the tool to do it with.)

  7. #7
    Join Date
    10th June 2005 - 19:24
    Bike
    KTM 250exc
    Location
    Napier
    Posts
    1,814
    well we just used a really big bolt head that weighed about a kilo and a punch with steel hammer to spread/rivet the chain link. didn't have the proper tool...

  8. #8
    Join Date
    12th June 2004 - 23:15
    Bike
    ..
    Location
    ..
    Posts
    2,797

    Thumbs up

    Two pair of hands work well. My Son held a heavy 25mm bolt head against the back of the chain links and I hit the pin with a centre punch. The hit was firm with a steel hammer. Not hard with two people. The side plate fits very snugly onto the pins of the joining chain. I use an over sized socket that is big enough for the pins to go inside but small enough not to hit the chain links next to the one you are putting on. If that makes any sense. Make sure the link plate goes on evenly. Because if it goes on to one side more than the other it can be hard to even them up. While I fitted this plate my son held the back of the link with the said 25mm bolt head so I could tap it on.

    The hard part is to have all the other gear. Like a compressor and a rattle gun to get the clutch cage off and a good socket set and Allan key set. A manual is essential unless you know about timing marks and the correct replacement of cam caps etc. With the info and the gear it is easy. Make sure you have no pressure to get the job done. Like a track day in Taupo..... ....My sons first track day and his bike was in bits in the shed waiting for parts. Life was stressed.... Good luck. Take your time and read plenty. For us it was a good learning lesson but with the gear we have it was easy. One more tip. Never tighten the cam caps if there is any pressure on the cam lobes. Things will break.

    Have fun.

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
  •