Anyone change their fork oil at a regular interval?

mxgolf

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I need to do mine too. I have had new springs and oil for a few years now but not done the deed. You all have inspired me to get er done. :cheer: Thanks
 

FinalImpact

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I need to do mine too. I have had new springs and oil for a few years now but not done the deed. You all have inspired me to get er done. :cheer: Thanks

Lets do it! :thumbup:
I see beer and supervision in your future Mr Ohlin's rear shock man!

Although you could spring for an emulator set and I'll bring the beverages!
 

FinalImpact

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Changed out my fork oil yesterday, and mine was super nasty as well. Some sort of gray slurry-type crap. Flushed several times with clean oil. Also found out that the springs were installed upside down by PO vs what the manual says, longer spring coil distance portion was on top. Not sure how that would make a difference though.

The inversion of the coils may explain some of the added metal. More coils in contact with the stanchion tube and all moving up and down with ANY movement of the bike.
More surface area in contact + moving all the time = more metal bits produced. I don't suppose you measured the free length of the spring?

Take a moment and check your sag, report back! tks
SAG: This is BEST DONE with a helper but can be done if solo. This will give you an idea.
The quick test is to obtain the difference between fully extended forks and collapsed fork distance with rider weight. Your goal is to see if the current spring rate will obtain a SAG of 38 to 32mm of sag. If this true and the static sag of the bike alone is acceptable, the spring rate may be OK as is for weight of bike, rider, and gear. But in most cases us the riders & gear are above 150 and the OEM rates are too low for best performance.
- Position bike in a location where you can hold yourself up with one hand while your full body weight is on the bike and in riding position (well minus arm prop).
- Fully extend the forks (block under headers).
- Loosely install zip tie on a stanchion tube and push it all the way down to the forks seal. Measure to it from from triple clamp down. Record value (mm preferred).
- Remove bike form center stand.
- Get on and into riding position.
- Push ziptie down down to fork seal and have helper measure from triple down.
-> If solo, use a long stick and reach down and push the ziptie down but don't lean forward MORE than you would while riding! NOW, slide back on the seat and get off the bike. Carefully rest it on the side stand and measure the ziptie. Repeat a couple times to confirm your measurements.

There are variants of this process, like measuring the bikes sag w/out the rider, and repeating to factor in stiction, i.e. pull up on nose, let it settle - rider returns to riding position and then measure it. Push down on nose, let it settle - rider returns to riding position and then measure it. Do some reading on this topic if you wish to improve the bikes performance.

IMO - It never hurts to know the number on the rear either. Both are easier obtained with a helper but can be done if alone if you get creative!
 
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oldfast007

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Help me here...getting a sag measurement I can see, but our "stock" forks have zero adjust-ability unless you change the spacer, which in my mind only changes pre-load and yes sag as it were?
The oil is a set viscosity that when changed (oil weight) does effect the damping rate only? Thinking rebound is more effected by the spring itself.

Thanks!

Eric.
 

Ohendo

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Agree with previous post ^^^^

I did not measure the spring length. And I'll try later on to get a sag measurement, but as the previous post points out, there's nothing to adjust on the FZ6. I guess if it's way out of spec you know it's time for new springs, but that's about it.

Thanks for the the how-to on measuring sag, I'll post back when I get some numbers.
 

FinalImpact

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Help me here...getting a sag measurement I can see, but our "stock" forks have zero adjust-ability unless you change the spacer, which in my mind only changes pre-load and yes sag as it were?
The oil is a set viscosity that when changed (oil weight) does effect the damping rate only? Thinking rebound is more effected by the spring itself.

Thanks!

Eric.

All very true.. .. ..
1) there is no adjustment per say, but knowing it lets you make an informed decision.
2) pre-load can effect sag = true
3) if the sag can be set to a desired number by manipulating the pre-load, now we are in a position to determine if the spring rate is appropriate for bike & rider.
4) oil effects damping rates (comp & rebound) = true
5) rebound rate is a factor of damping

The basics; is the spring proper for the bike and riders weight. Gathering information gives us insight. Well unless everyone is happy as could be as is.

What I felt the first time I rode my 08 w/4000 miles on it was this.
The front is too bouncy and does not control compression damping, it does OK at rebound damping but honestly because the back shock does so horridly at rebound control the nose sinks during basic light events like braking and corner entry. Couple this with the rear kicking like a mule and its bad combination for "me".
That said I have different expectations from the bike than many. If we were to cruise up and down the slab or take a leisurely stroll it rides nice and smooth and its acceptable albeit a tad unpredictable even while cruising.

So, after changing the fork oil and not gaining control I wanted, I knew it wouldn't meet my needs for spirited cornering and harder braking and all that. For me it became a cost analysis of make it better (at $cost of$) or replace it. So I changed out the front forks. After gaining control of the rates up front it evident that the back is still kicking like a mule do to the lack of rebound control. With the nose being compliant over a bump and back absorbing it nicely but kicking me in the seat AFTER the bump, I knew i needed more control there too, hence the revalved R1 shock.

I've spent hours tweaking both the R6 nose and the R1 rear to dial it in and how it behaves. To my satisfaction, both ends are now very compliant over all sorts of terrain and its a joy to ride! My only regret with the current setup is that it can be harsh over choppy roads as neither of the technologies offer high speed adjustments.

That said, if you know what your working with you can hopefully make informed decisions about how to get to where you need to be. Also, i like recording the "As Found" info so I have a reference point to compare to later.
 

tyler2011

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Also found out that the springs were installed upside down by PO vs what the manual says, longer spring coil distance portion was on top. Not sure how that would make a difference though.

Now that you mention it, mine was that way to. Is it possible we are interpriting the top as the wrong end of the fork?


Sent from my DROID3 using Tapatalk 2
 

FinalImpact

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Now that you mention it, mine was that way to. Is it possible we are interpriting the top as the wrong end of the fork?


Sent from my DROID3 using Tapatalk 2

The coils with less space between them go to the top.
In the case of OEM variable-rate springs the 1.20kg/mm are the tighter spaced section towards the top. The 0.75kg/mm rating are Loose space that easily compress go to the bottom which moves all the time. Because the top is Fixed, we want that end to have the higher spring rate as its only going to compress under maximum load.

Picture - Stock is left, HyperPro on right. Tight space coils towards triple clamp (top) From: http://www.600riders.com/forum/fz6-mods/13665-hyperpro-springs-installed.html
13946d1237107351-hyperpro-springs-installed-img_0055-jpg



Just to add to the confusion, here is a fixed rate spring. Both ends appear the same with no obvious variance in the spacing. Rate is 0.88kg/mm and its linear over distance compressed.
picture.php
 
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ZeFz6

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Hi
I´m new here. So far Í´m just Reading old posts.
I´ve just bought na fz6 s2, still in the process of servicing and getting it ready for MOT. Didn´t ride it yet:shakehead:

Just changed one of the fork stanchions and the oil was something green..ish muddy thing :(

The sping acording to Haynes manual is the other way around... the tighter spaced rings to the bottom... they were as you said the other other way around. I trusted the haynes manual but it looks like I shouldn´t...
 

2old2ride

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Is that the procedure (i.e. take the forks off) or can they be drained and filled without disassembling them from the bike?

I don't think so. Although it might be possible to loosen the damper bolt on the bottom of the outer tube and let it dribble out. I have a service manual and it says to remove the fork. I'm doing the stem bearings also so my front end is laying all over my man cave.
I should be working on it now but The upper race is being a Mo-Fo and I'm tired of laying on my back trying to swing a hammer to hit the end of the shotgun cleaning rod I'm using as a punch.
I want to finish the bearings before I take the fork apart. Taking them off was way less trouble then pulling the plastic. :eek:
I'm going to a .95 spring and stock fork OIL. I think I will use a suction pump to change fluid in the future. I know it won't get the debris out but If I do it right and keep up with it as a maintance item, there should be no debris. I'll decide that after I blow out the OIL passages in the damper. I'm either gonna run mineral spirits or kerosene through it a couple times then let it dry overnight.:thumbup:
 

TownsendsFJR1300

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My local shop, on simple fork oil changes, pulls each tube.

Then he'll put the fork tube upside down to drain in a container thats marked for an exact amount of what was in there (unless it was leaking).

I believe he would then put some fresh oil in, pump and drain again (getting the gunk out). Then re-fill with the original amount already measured..


In the OLD days(70's), Yamaha put a small, phillips head drain screw on the side of each fork, right near the bottom, for flushing. Pull the screw, pump the fork and watch the oil shoot 20' off to the side!!! That'd be way too easy nowadays...
 

FinalImpact

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I don't think so. Although it might be possible to loosen the damper bolt on the bottom of the outer tube and let it dribble out. I have a service manual and it says to remove the fork. I'm doing the stem bearings also so my front end is laying all over my man cave.
I should be working on it now but The upper race is being a Mo-Fo and I'm tired of laying on my back trying to swing a hammer to hit the end of the shotgun cleaning rod I'm using as a punch.
I want to finish the bearings before I take the fork apart. Taking them off was way less trouble then pulling the plastic. :eek:
I'm going to a .95 spring and stock fork OIL. I think I will use a suction pump to change fluid in the future. I know it won't get the debris out but If I do it right and keep up with it as a maintance item, there should be no debris. I'll decide that after I blow out the OIL passages in the damper. I'm either gonna run mineral spirits or kerosene through it a couple times then let it dry overnight.:thumbup:

JM2C but I can't bring myself to flush with a solvent which will not completely evaporate as leaving it behind it will dilute the new fluid breaking it down. Perhaps if it was real nasty I'd take them apart?!?

That said, an extra bottle of fluid and pump it through a few times. Fill to the desired level and call it done.
Level: 134.0 mm (5.28 in) <> SPRINGS REMOVED, STANCHION COLLAPSED!

^^ not sure what the issue is pulling the plastic. The fairing comes off in 10" or less for access to the head. Drop the inner panel (fairing), undo the two wire harnesses and the two 12mm bolts on the RS and its in your hand.

The only thing I would add is to to loosen all of the brake, pinch and fork bolts, fork caps while the bike is grounded. For those w/headers, a 7 to 8" block under the headers and your set to pull the nose apart.

Grab some grease and clean an grease the axle hardware + seals and your set.
 

Carlos840

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There really is no need for solvant, just cycle some fresh fluid a couple times while pumping the fork and it will come out clean after 2 or 3 times!
 

TownsendsFJR1300

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^^ not sure what the issue is pulling the plastic. The fairing comes off in 10" or less for access to the head. Drop the inner panel (fairing), undo the two wire harnesses and the two 12mm bolts on the RS and its in your hand.

.

I was checking/cleaning those two plugs yesterday, got the one apart after much screwing around. The other, with the waterproof seal and THREE RETAINER clips, could never get that one off... PIA..

I need to change my fork oil too but I'll wait till it cools down a little bit, and do the flush thing with extra oil.

Probably put those "Schrader valve", air fork caps on as well (I made awhile ago).. Air over springs with unlimited adjustment.
 

2old2ride

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JM2C but I can't bring myself to flush with a solvent which will not completely evaporate as leaving it behind it will dilute the new fluid breaking it down. Perhaps if it was real nasty I'd take them apart?!?

That said, an extra bottle of fluid and pump it through a few times. Fill to the desired level and call it done.
Level: 134.0 mm (5.28 in) <> SPRINGS REMOVED, STANCHION COLLAPSED!

^^ not sure what the issue is pulling the plastic. The fairing comes off in 10" or less for access to the head. Drop the inner panel (fairing), undo the two wire harnesses and the two 12mm bolts on the RS and its in your hand.

The only thing I would add is to to loosen all of the brake, pinch and fork bolts, fork caps while the bike is grounded. For those w/headers, a 7 to 8" block under the headers and your set to pull the nose apart.

Grab some grease and clean an grease the axle hardware + seals and your set.

I think Mineral spirits will completely evaporate, given enough time. We will see. If not, I have a needle attachment for my computer vac that might fit. Not sure yet because I haven't pulled the fork cap all the way off so I can look inside to see what is what. I have done a conventional fork before but they are not all exactly the same.
Right now I'm on hold. The stem bearings I got from All Balls are not the right ones. OD and ID look ok but the height of the race is greater then that of the ones I'm taking off. Seated it looks like they will stick out almost as much as they stick in. I cross checked the part number with the product guide on their web site and it says FZ6s 2004 - 2009, which would be correct. But the part number I used I took off a bit of cardboard in the blister pack the bearing came in. So that card might be in the wrong pack. I measured as best I could with a metric ruler (not having a metric caliper) and got 12-13mm for the old bearing and 16-17 for the new. Too much for me to feel right about trying to fake it.
So is this something new? Am I just being an old scardy cat? I'm gonna run down to the dealer and ask them tomorrow. They close Monday.
I took off the plastic because the shop manual said to. I'm in no hurry. Around here, normal temps for July and early August are high 90's, low hundreds. Too hot for me to ride. Which is why I'm doing this now.
The old bearings are toasted. I suspect they were marginal new. That is why I want roller instead of ball. If I have to swap them for OEM, I will but I won't be happy. Now or when I replace them in 15,000 miles.
 

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There really is no need for solvant, just cycle some fresh fluid a couple times while pumping the fork and it will come out clean after 2 or 3 times!

I'm being cheap. A liter (litre for the Euros in the room) of 5w Maxima costs 11.99 US$ A Quart of mineral spirits cost 99 cents. Mineral Spirits is closer to gasolene or kerosene then OIL. Of the 3 Mineral spirits evaporates faster (more volatile). With Mineral Spirits I can do a couple cleaning cycles for under 5.00$ US. That would be 25.00 US using Fork OIL. That's a tank of gas + smokes.
I'm cross-eyed tired right now. Both brain cells have left the reservation. I haven't done this in over 30 years, so let me sleep on it, then try tomorrow. The biggest problem with Sr. Moments is you don't know they are happening until later.
 
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FinalImpact

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I was checking/cleaning those two plugs yesterday, got the one apart after much screwing around. The other, with the waterproof seal and THREE RETAINER clips, could never get that one off... PIA..

I need to change my fork oil too but I'll wait till it cools down a little bit, and do the flush thing with extra oil.

Probably put those "Schrader valve", air fork caps on as well (I made awhile ago).. Air over springs with unlimited adjustment.

Ya them little Japanese engineers are tricksters... Some tabs are depressed while others are spread.

Do keep in mind not that not all seals hold pressure well. I'm not certain the oems are intended to do much more than cycle the static pressure. But you should do it for the better of the 4'uhm and tell us how it goes... :thumbup::thumbup:
The roads are so rough in some places it'd blow them off the seats or make them leak! Although they may not hold pressure anyway?? IDK! Try it!
 

TownsendsFJR1300

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Ya them little Japanese engineers are tricksters... Some tabs are depressed while others are spread.

Do keep in mind not that not all seals hold pressure well. I'm not certain the oems are intended to do much more than cycle the static pressure. But you should do it for the better of the 4'uhm and tell us how it goes... :thumbup::thumbup:
The roads are so rough in some places it'd blow them off the seats or make them leak! Although they may not hold pressure anyway?? IDK! Try it!

All three of my KLR's (2 250's, 1 650) all had schrader valve caps from the factory. (In the old MX racing days, springs were often pulled and ONLY air used). For street use, they were set at 0 PSI. We're talking maybe 10 PSI. I'm happy with the stock forks as they are, perhaps just a tad amount of air and see if it helps, hurts, etc..

**You could also replace the fork seals with AIR PRESSURE ONLY (on the KLR's) after removing the retainer rings (same as the FZ) but with 100+ PSI. A rag over the seal helps keep oil from blowing out all over the place too.

Should my seals start to leak, that's how I plan to replace them. Of course the inside of the outer fork, were the seal is pushed in, must be cleaned/spotless.

BTW, back then, ATF was often used instead of fork oil. I wouldn't use ATF in the FZ for regular use however, for flushing, likely a little cheaper, probably thinner (easier to flush) and an alternate. Mineral spirits, in my experiance leaves a residue. Either ATF or extra fork oil would be my choice for flushing W/O disassembly. Lots of upside down, drain time as well.
 

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Got around to opening the forks this morning. The fluid was pretty clean. I was surprised. The springs were in backwards. At least according to the service manual. The tighter coil was down where logic and the service manual say it should be up. That very well could cause the forks to be soft when they should be firm. Plus the new springs are 318 mm free length. The Service Manual says 354 to 347 spring free length. The ones mounted upside down are 354. So at this point I'm tempted to just put the old springs in right and see if the change is good.
The OIL was so clean that I think the PO had the springs changed not long before he sold me the bike. This way I could send the race tech springs back or put the money toward rear sets. It looks like pulling the damper without the Yamaha 95 $US "Special tool" has the potential to hit PITA levels I don't really want to go to. I have a leaking seal or bushing on the clutch side fork.
It might be smarter of me to just take the fork, the new seals and bushings down to the shop and pay some dude with the correct tool to do it for me. Maybe if I go early in the morning nobody will see me. ;)
 
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