How much of the front forks do I need to replace?

[charlie12]

Hey All,

I bought an '04 FZ6 this April with 20k miles on it, and put 3500 of my own on it over the summer. I bought it from a friend, who is about 230 lb and who drove VERY aggressively and rode the bike on the track regularly. When I bought it, he said that he was going to be replacing the front suspension early this summer, but since I weigh less, I might be able to get one more season out of it.

I weigh 160, and the suspension is certainly too stiff for me (I think). Also, as my friend predicted, the front forks are definitely not doing well. They squeak (more of a quick chirp) every time I hit a big bump or pothole. I live in Michigan, so our roads are more pothole and patch than not. The forks still seem to be working decently, but the noise is worrying me.

I'm wondering, given that the noise is really the only problem I'm noticing, what needs to be replaced? Would just new springs and oil do the trick? I'll probably do that regardless just so I can adjust it more for my own weight, along with putting a new rear shock on.

One other random question -- given how hard the previous owner thrashed this bike before I got it, is there anything in particular I should look into apart form the normal maintenance items detailed in the manual?

Thanks!

 

[Shamus McFeeley]

I would definitely suggest a new set of springs tuned to your weight. The oil will have to be changed of course, along with the wipers. As far as everything else, you will have to inspect the parts once you have the fork apart to make sure they're not damaged. You won't know the whole story until you open both forks up.

People have different definitions of aggressive, but if the previous owner was that rough, you may want to check the valve clearances.

 

[Spideyrex]

In addition to springs and oil, maybe the seals need replacing? A cheap option would be to buy some stock springs from someone who upgraded their forks already.

What did your friend to to the fork already? Did he change the springs or add a longer spacer to bump up the preload?

 

[TownsendsFJR1300]

+2 on bothe above responses... Definitly change the seals, that's probably doing the squeeking as the seals are drying out...

If you pull up on the dust seals, some folks have found using a thin piece of old film strip will clean any crap in between the seal and the fork tube itself. If you spray just a very little bit of silicone spray above the seals (once their cleaned up, blown out with an air compressor preferrably) the squeek will likely stop, verifying the drying seals...

I know my local shop has a guy that does fork rebuilds (nothing else) they send any fork to that needs work. Quite a bit cheaper if you remove the fork legs and drop them off as well, something to consider..


The below site shows the break down of the forks and the metal slides, if the forks are worn that need replacing...

http://www.yamaha-motor.com/partvie..._(2004_MOTORCYCLE)/FRONT_FORK_(FZ600SS_-_2004)


Main site with Yamaha part #'s: http://www.yamaha-motor.com/partviewer/default.aspx?ls=sport

 

[Norbert]

spray the seal and upper part of the tube with silicone, then pump the forks 10 times. you should see a ring of dirt. clean that off. clean off the excess silicone with a dry towel, too.
EDIT:
so the steps I do are:
-clean area around the seal and a few inches above (below if you have USD forks) it with water and a microfiber towel.
-coat the seal and the area above it
-while the front brake lever is pressed, move the forks up and down a bit.
-stop and clean the area around it. maybe re-coat.
-keep this up until you do see a ring of dirt anymore
-use another towel and clean up ALL the excess. you don't want extra spray there, it might attract dirt.
i usually repeat about 3 times.
one thing is that some silicone sprays may be harmful to your seals. they contain other things like petroleum distillates. i just use acf-50/corrosion block. usually the spray will say something about being harmful on varnish or something....