Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

DIY Front spring replacement - GPX 250

Discussion in 'Maintenance and Servicing' started by Samboss260, Oct 8, 2012.

  1. My replacement front springs have arrived, and I've researched several sources including ninja250.org, the service manual and various other bits and pieces.

    Essentially, all are doing is changing the springs and replacing the fork oil.

    My questions is, do you have to remove the actual forks out, or can you leave them in? Some sources say leave them in and some say take them out.

    If we leave them in, our ( a friend who is a bit more mechanically minded) is to remove the springs from the top of the fork, them drain the fluid from the lower nut, all whilst the forks are intact.

    Has anyone done this mod at home on their GPX? Did you have to remove the forks out completely?
  2. I took the whole front end apart when I changed the springs on my GPX. I didn't bother with removing the fairings though, but if you don't already know where things are removing the fairing will make it easier to see what you're doing.

    Remove the springs whilst the forks are still on the bike, since that way you have something to hold them in place. Don't worry too much about any of the fancy tricks described in the Ninja250.org guide for removing the clip, it's easy enough to just push down with a large screwdriver (or something similar) then use something pointy (in my case a knife blade) to expose the clip then use something else (in my case needle nose pliers) to grab it. I managed to do this on my own easy enough (using three tools at once is an art :LOL:), so if you have someone helping it should be dead simple. Just be very careful easing off the pressure on the screwdriver once the clip is removed, as the springs will fire the bit on top a fair way into the air if you're not careful (usually coming down with sufficient force to leave a nice dent in the top of your tank).

    Remove the front wheel and brake caliper (don't let it hang by the hose), then all you have to do is loosen the bolts on the two clamps holding the forks in place (actually a sobering thought when you realise how little holds them in place). Remember to measure the height of the fork relative to the top of the triple clamp, so you can make sure to put them back at the same height (changing this has a big influence on how the bike handles, so best to stick with the factory setting unless you know what you're doing). Do one fork at a time, and you'll likely need to twist it a little from side to side to get it to move (don't try and force it).

    Reason for removing the forks is simple. You get a lot of crap in the bottom of the forks (mostly wear debris from the moving parts) and most of this won't be removed by using the drain plugs. So far better to tip them upside down to drain them fully, pumping them a few times to get all the crap out. I actually used a little bit of left over fork oil from my other bike to wash and flush the forks further, but you can just as easily tip a bit of the used oil from the top of your forks into a separate container for this purpose (you should see a big difference in the quality of the oil between that up around the spring, and that down in the bottom part of the fork.

    Reassemble, using the new spacers and fork oil level recommended for the new springs, and you're good to go. Take it very easy at first though, just in case you've made a mistake, and after a short run recheck that all the bolts you did up are still tight.
  3. As JD suggested you should get the forks out, so you can get all the cr@p out of the bottom, depending how old the oil is, it can be pretty sludgy, and lotscof alloy sparkle in it that you want to flush out properly..
  4. I suggest that while you have the forks out, change the seals and bushes.

    Last thing you want is to flush them out, fit the new springs..then in "X" number of months have to pull it all apart again because you were too lazy to change $30 worth of seals and bushes when you had it all apart..

    just my 2cents
  5. If you can put a rag over the top of the tubes when youre getting the clip out it will stop bits flying away. Makes it harder to do but less damaging to tanks and eyeballs.. Easy enough to put the rag handy so that after the clip is out and before you move the screwdriver, grab the cloth with your other hand and wrap it around the screwdriver as you release the spring tension..
  6. Cheers for the tip foot69