How to service (some) LC4 forks

Discussion in 'Thumpers' started by meat popsicle, May 7, 2008.

  1. dagwood

    dagwood Banned

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    ug. again. I really didn't want to pull the springs out again. I'm at 400 ml. of oil. I'll get the rest of the bike put back together tonight and go flog it. adjust the damping and rebound and see whats it's like. I definitely don't baby it so it does seem like I have lost about half the travel. I'll check the torque on the lower clamps also.:bluduh :bluduh

    thanks.

    oh it's half Royal Purple atf 5.0 and half castrol?2.5 fork oil. I was recommended this in another thread somewhere.(along time ago) everyone? said the WP valving don't like 5.0 or thicker so trying to get inbetween is mixing viscosity. :choppa
    #21
  2. Zerodog

    Zerodog Long timer

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    MIX OIL BRANDS?? That could be bad news. You could have made cottage cheese or something in your forks? Some oils do not play well together. At least that is what I have heard, so I don't do it.

    5wt is good. 2wt is pretty damn light for the stock valving of any 43mm fork I have worked on. They are set up LIGHT. 400ccs is probably too low. The only real way to measure and know for sure is the top down measurement I mentioned.

    Set your clickers like this to start with
    Rebound 16 out from full shut
    Compression 15 out from full shut

    Check your torque, and make sure you clamped your axle the correct way! You can really mess it up with the axle too.
    #22
  3. meat popsicle

    meat popsicle Ignostic

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    One of my fork seals was dirty and before I could clean it with the business card trick it leaked some unspecified amount... so I too have to pull my springs to get it right. :bluduh Although it does make me smile every time I am given a business card now - something to clean my fork seals with!

    Didn't find any royal purple fork oil thread with mixing easily.
    #23
    rustytigwire likes this.
  4. paddyhannen

    paddyhannen Been here awhile

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    Gda boys and bmw riders,
    The mighty lc4 ( some people say is invincible)
    is a little bit vincible.
    Freshwater creek on beach plus $1 or 60mph for the imperial boys plus
    640
    =
    damage=
    vincible.
    quite vincible it seems.
    since then ive found=
    2 dead triple clamps
    dead stock bearings
    dead triple clamp nut
    very dead front HUB
    dead disc
    very dead fork stauncheons
    probably dead swingarm
    2 folded radiators from impact.
    sooo, =
    new triples and assorted paraphenalia, fitted new damper and top triple from rallemoto ( MSC Titan) which is truly awesome but is set up for later forks than mine and is interchangeable btwn the 640/950/990 so its 53mmish not 50.
    what can i replace my forks with to suit within the confines of normal budget that will be at home with the whoops as current? what are the big girls running?

    im sure someone knose. sharing is caring.
    cheers.
    pads:huh
    #24
  5. wrk2surf

    wrk2surf on the gas or brakes

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    525 forks resprung ... and some of you aussies sure have the prose down..
    #25
  6. meat popsicle

    meat popsicle Ignostic

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    If'n I follow yer Australish, you bought triples for 53mm forks - but your forks are 50mm - and you want to know what decent yet cheap forks you can buy that are 53mm eh?

    ps - this is a how-to service forks thread not how-to buy forks; prolly was the first fork thread in the index eh? :D
    #26
  7. Frougby

    Frougby Been here awhile

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    Great thread Meat P
    :thumb
    #27
  8. meat popsicle

    meat popsicle Ignostic

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    Yay, someone used it! :clap

    I had to take a peek - it had been awhile - and my own thread reminded me of some stuff. I wish I had a garage this winter...
    #28
  9. jamesdemien

    jamesdemien Been here awhile

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    Meat-
    where did you get that fancy orange tool?

    [​IMG]

    Also, does it fit the cap? and do you know what size the cap bolt is.

    I'm following your guide next week to refill my forks.
    #29
  10. bmwktmbill

    bmwktmbill Traveler

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    #30
  11. joekanter

    joekanter Been here awhile

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    Great Write up Master Meat Popsicle. Thank you as always. Hey guys. Life has caught up with me and I haven't posted any noob, annoying questions. Just got my 07 LC4A up and running after I installed a Scott's dampener. Forks took a dump after a break in ride for the Scott's and needed some loving attention. BTW-that dampener is very cool to play with. I followed all these posts before I dove into things. As with other bike maintenance that has intimidated me-once I dove in, I realized that it wasn't that hard after all. Cleaned everything out and new fluids. That triple retail Motion Pro worked great. But I also used the 35mm film trick and Starbucks tunes card to clean out seals. So far, so good. So now the forks are showing me some joy. But I suspect after 7K the seals will need to be replaced by next season. Any opinions on after market parts made by Synergy and Moose? Or just stick with the OEM's?
    #31
  12. meat popsicle

    meat popsicle Ignostic

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    Hey Joe,

    I have not heard anyone comment on the various seals or offer an opinion. I am guessing Zerodog could if prodded... or if not I could try to ask the other tuner here in Cali.

    :beer
    MP
    #32
  13. Truckin_Thumper

    Truckin_Thumper low profile

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    I would go with Synergy or Moose over the OEM.
    I am rough and loving on my LC4 and I think the OEM are just, well....there.
    At $20 a seal, I would expect better quality :thumb
    #33
  14. Zerodog

    Zerodog Long timer

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    This is what I have found as far as seals go. You can take it or leave it

    Synergys can work ok. Some swear by them, some report lots of stiction with them. This in my book is bad. I had them leak at the same interval on one of my old dirtbikes. I went back to OEM on that bike. Not worth the $$ in my book.

    Moose is cheapo aftermarket

    Pivot works, I really wanted to like because it is a complete kit with bushings, seals and orings. It is also really cheap for me to buy from my distributor. But it is a piece of shit. The bushings do not fit the fork correctly and will cause long term problems. I didn't get as far as trying the seals. I would imagine more of the same. If anyone wants some pivot works seals and wipers to try $20 and I will sell you the brand new set.

    MSR is junk too. Tried these on my 640 A for the same reasons. I can get them cheap. They lasted 1000miles of easy riding. That is pretty weak.

    OEM is really good stuff. These do last for a long time when installed right. The downside is $$$

    MX-tech makes a good 48mm seal for less money. Not too bad.

    Pro X makes a good 48mm seal kit with wipers included that seem to be holding up very well since I have started using them. They are supposed to be OEM NOK seals. But?? They are made in Japan though. To me that is a good thing. I have installed these in lots of customer bikes with very good results. And I am running them on my bikes too. I sell this complete for $60 seals/wipers.
    #34
  15. meat popsicle

    meat popsicle Ignostic

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    Thank you Z-dog :beer I added a note and link to your post to Page 1.
    #35
  16. joekanter

    joekanter Been here awhile

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    Master Meat and Zerodog

    Thanks guys. My brain hurts. I'm chewing the cud on this one. My wife wears the financial pants in our house. She lets me take them off..though. I just have to figure out a cost effective and durable replacement. Then let her know what I'm doing. She's very cool. Just likes to bore-ass me about the bike. The cost of ownership I guess. LOL. My 07 640A just turned 7K. The dealer changed out fork fluid around 3.5K. Kept the bike clean. 50 50 riding in mostly dusty conditions. I would have liked to get more miliage out of the seals. Is 7K acceptable? So I did the oil change last week and just took the bike out for another shake down ride. Right side looking like its weeping. Not nearly as bad as before I did the work. So I might as well just replace the seals and be on with it.

    While I'm at it. How do I know if the dust wiper is shot? Or is it a matter of practice to replace both the wiper and oil seal at the same time. I had to laugh. As I'm pricing this stuff out, I realized the KTM OEM's are not for a pair, but for one. LOL.:eek1

    I'm curious what other folks have done miliage wise with OEM's or Synergy's.






    Thanks again.
    #36
  17. bmwktmbill

    bmwktmbill Traveler

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    RTW on OEM seals, no issues at all.
    Rear shock rebuilt before leaving by Z-dog.

    Grease under the wipers, neoprene boots for the forks.
    Forks rebuilt by me(and revalved)
    Suspension shortened front and rear.
    bill
    #37
  18. Zerodog

    Zerodog Long timer

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    First off, you need to train your wife better, motorcycles are really important. You need to spend more $$ and have more of them. She just needs to understand this fact and your life will be easier.......

    About the seals. Brand new seals of any brand can leak if you subject them to the right sort of mud. It just kicks their ass. As Bill said fork boots can work. But again under the wrong conditions they can make life bad. I have pulled those boots off of more than one fork to find gravel trapped under them just rubbing away on your nice chrome legs. But in dust, they can be like an extra wiper.

    If you haven't done any mud and you have new seals that are leaking that is not normal. The dealer may have used shitty seals, or just done it wrong. Or worse, not done it at all. Yes, I have seen this too. In general, dealers suck at suspension work. I'm sure there are exceptions to this. But from what I have seen, the only thing they are good at is making your ass hurt from the reaming they give you when you get your bill.

    For road use and some dirt road action with I usually see LC4 suspension give up around the 10,000 mile mark. This isn't a goal. This is long overdue at this point. But this is usually when stuff leaks. I have seen them go even longer, but in general that is just bad on the internal components.

    #38
  19. joekanter

    joekanter Been here awhile

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    Last year or so, I had the dealer change the fork oil. No seal replacement. So I got 7K on the origional seals.

    I'll have to show her this quote. LOL. She gave me the thumbs up to get the seals and wiper, then tells me to get the proper tools so I don't start "crying" next week. But I might be the one with the last laugh. She inherited her fathers 2001 BMW Z3. It's sitting at the local BMW shop and the work estimate is rising pretty fast. Just got to love the OBD fault codes.

    So I ordered the oil seals, and dust wipers. I figure I may not need the wipers, but will compare them to the old ones and see how they look. Also a nice Motion Pro seal press and bullet.

    Thanks again guys for the input. Have a great weekend. :beer
    #39
  20. meat popsicle

    meat popsicle Ignostic

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    I am over 17,000 miles, and my fork seals may have given up the ghost. Problem is I will have to pull the forks, and partially disassemble them to refill the oil and set the height :bluduh just to find out if cleaning the seals was or was not enough...

    probably why a suspension tuner told me he just goes ahead and changes the fork seals with every rebuild; it's cheaper than doing them later. :lol3
    #40