Major maintenance: bearings, spark plugs and fork oil

[elus1ve]

So I have owned this bike for 3 years now and have finally gone ahead with some major maintenance work (at least to me). I didn't feel confident doing those myself so had a good mechanic do it.

1) Steering bearings. According to the mechanic, the bike is still rocking the factory bearings. For 72,000Km, he says they aren't so bad but I'm glad I got this replaced.

2) Changed the spark plugs. They don't look too bad but apparently my engine is running a bit lean. I only have a K&N air filter that I clean and regrease every year, so don't know why it's running lean. Also did the spark plug cap as suggested in another thread here except the mechanic simply cut a 1 or 2 mm of the tip of the cable before putting the cap on.

3) Fork oil changed to 10w. The old oil was still ok so the PO must have done this before selling the bike.

Unfortunately I got a couple of bad surprises. Front brake pads are gone and need replacement asap together with the front tire. I knew about the front tire but the state of the brake pad was a bit shocking.

The worst is that one of the fork springs are not equal. Meaning that one of the spring is more compressed than the other. It was obvious when he was assembling the forks, one had the spring pushing the against cap and the other just bottomed down. Also while reassembling the fork and the front wheel, he had to leave the forks lopsided for a free rolling front wheel See pictures to get a visual. He suggests I replace those springs soon so that I don't have to change the oil again. He can just open up the cap and replace the springs.

So I'm gonna have to spend on new brake pads, front tire and springs very soon.

On the upside, the nose doesn't dive that much on braking anymore and it is more stable on bumpy roads. The engine is a bit smoother thanks to the new spark plugs and the cap. On the downside, the fork oil caused the front tire to lock/skid easier on hard braking. I had a scary two wheels sideway skidding when coming back from the maintenance. Have to get used to the fork / braking again and it also makes changing the front tire more urgent.

As for the springs, what would you advise me to get: OEM springs or stiffer aftermarket springs? For a small ride back, the suspension seems to behave better, so is it going to be even better with stiffer springs?

 

[elus1ve]

I didn't take a picture of the brake pads but both sides show only one pad (the one on the inside) being completely used up while the other still having a good thickness left. Mechanic says pistons need to be cleaned up.

Going to have another garage/maintenance session with the mechanic soon so if you have suggestions on things to adjust or verify - please do

 

[TownsendsFJR1300]

Re the brakes; looking at your profile you have a S2 model, 4 pistons per pot/side.

Yamaha recommends replacing the piston seals every TWO YEARS. In real life, I've found you can usually get maybe 5 years out of them before they hang up too much and drag excessivly.

You can clean the outsides of the pistons, that will help, BUT the rubber seals inside still harden up over time and don't release the pistons / pads fully.

The pad with more wear has a piston NOT releasing, thus, it keeps rubbing against the rotor and wearing.

I've done my current S2 FZ and my old FJR (same ft calipers) with new seals. All the seals are a little bit over $100.00 and are cheaper buying on-line than at the dealer...

With no major issues, figure 1-2 hours R&R and bleeding.. If they've been flushed semi regularly, the pistons usually hold up well without pitting (nor replacement).

 

[elus1ve]

When I ask for suggestions, I didn't really want more reasons to spend :spank:

But darn, it looks like I might need to fork out some more to get this done and might as well change the brake lines too. Thanks for the info Townsend.

 

[FinalImpact]

Maybe I'm missing something but the fork cap issues seem to be a bad setup by workmanship. In short, the upper and lower triple must be loosened and the stanchion tube set to the same height. As it is now, top out and bottom out lengths are different.
Picture a big rectangle with all 90° angles. The axle is held by by forks but when they bottom or top out, they currenetly have different stopping points as they are NOT installed at the same depth.
Loosen one side and raise the tube to match the highest other. Tighten the clamps.
Let me know if you have any questions...

 

[FZSexy]

hey OP mind if i ask how much all this is costing you? i am new to 'cycles and am wondering what some pay compare to others. i also wonder if some of these things can be done safely by a "shade tree" mechanic? or at least by someone qualified and working "on the side"

in about a year and a half i will be having all this done by my mechanic. seems pricey, but who knows?!

Inspect and adjust valve clearance, synchronize carburetors/throttle bodies, replace spark plugs, service / replace air filter, replace fork seals and fork oil, adjust steering head bearings, change engine oil & filter, lube & adjust chain, adjust tire pressure, top off fluids, adjust cables & safety inspection

that is $840 but could most likely get it a hair under $800 without the oil change and chain adjust. which i do myself :eyebrow:

 

[TownsendsFJR1300]

Maybe I'm missing something but the fork cap issues seem to be a bad setup by workmanship. In short, the upper and lower triple must be loosened and the stanchion tube set to the same height. As it is now, top out and bottom out lengths are different.
Picture a big rectangle with all 90° angles. The axle is held by by forks but when they bottom or top out, they currenetly have different stopping points as they are NOT installed at the same depth.
Loosen one side and raise the tube to match the highest other. Tighten the clamps.
Let me know if you have any questions...

+1^^^

The tubes themselves should at least be even with the upper triple clamp.

Somewhat related, after loosening and adjusting the tubes, I would loosen the PINCH bolt on the lower fork leg (Do NOT loosen the axle). Put the bike on the ground and push the ft end up and down. RE-tighten the pinch bolt to spec's.

This procedure is basically to let the forks find thier "happy spot" so there's no binding. The fork (with the pinch bolt) will move in or out on the axle (it is designed that way) on its own.

BTW, it may be easier to adjust those tubes upward that slight bit with the pinch bolt loosened.

 

[elus1ve]

The guy who did the work is a full time mechanic that does some work on the side. My friend did his valve adjustments and a few things for less than C$500 all parts and labor included. Mine was less than C$400 for all three work with parts and labor as included as well.

Otherwise it would have costed about twice the price + tax. So yeah it was worth it for us.

hey OP mind if i ask how much all this is costing you? i am new to 'cycles and am wondering what some pay compare to others. i also wonder if some of these things can be done safely by a "shade tree" mechanic? or at least by someone qualified and working "on the side"

in about a year and a half i will be having all this done by my mechanic. seems pricey, but who knows?!

Inspect and adjust valve clearance, synchronize carburetors/throttle bodies, replace spark plugs, service / replace air filter, replace fork seals and fork oil, adjust steering head bearings, change engine oil & filter, lube & adjust chain, adjust tire pressure, top off fluids, adjust cables & safety inspection

that is $840 but could most likely get it a hair under $800 without the oil change and chain adjust. which i do myself :eyebrow:

 

[elus1ve]

I don't know if it was bad workmanship but the guy was very transparent about it. The way he did this was put the two forks through the lower triple and tighten it just enough so that it wouldn't slip down again.

He then took the wheel axle and made sure it went through the forks freely and at 90degs. So he ensured that the axle was placed properly.

Next step was to place the top triple on the bike again, since it was removed for the steering bearings. Once placed, that were he showed me that it was not level and his reasoning is because one of the spring is not extending the fork as much as the other even though both forks are suspended in the air with no wheel attached. He checked the axle again and it was correct.

He then gave me the choice to have both forks at the same level, which would have worked once the front wheel was on and lowered to the ground, but he recommended that we leave it this way to compensate for one of the 'fatigued' spring. Of course he said the best is to change the springs which will naturally set both forks level. I've gone with his recommendation hence the lopsided forks, and planning to change the springs.

If the forks are still lopsided after new springs, then I was going to question his workmanship... but so far he has done everything explicitly.

What do you think?

Maybe I'm missing something but the fork cap issues seem to be a bad setup by workmanship. In short, the upper and lower triple must be loosened and the stanchion tube set to the same height. As it is now, top out and bottom out lengths are different.
Picture a big rectangle with all 90° angles. The axle is held by by forks but when they bottom or top out, they currenetly have different stopping points as they are NOT installed at the same depth.
Loosen one side and raise the tube to match the highest other. Tighten the clamps.
Let me know if you have any questions...

 

[FinalImpact]

Even though one spring is weak, there is another mechanical aspect here (the big rectangle), and when you bottom the forks it's going to bend the axle because one is now stopping ahead of the other. And with a compromised spring, I'd venture to guess its going to bottom sooner than later.

So the issue is now that of fatigue.
Lets assume spring or no spring both forks fully extend and compress to equal lengths. AS THEY ARE NOW, one leg will stop compressing before the other. Although top out is the same problem its not as likely to exert damaging forces and bend the axle binding the rotor.

IMO even w/weak springs, set the tubes to the same height. And grab some new springs ASAP...
- Also i say "IT MAY bend the axle" (from STANCHION TUBES NOT BEING AT EQUAL LENGTH) but for all i know it may fracture the fork body where the axle is retained.
All i know is with unequal lengths, something will be strained when it bottoms/tops out....

 

[FinalImpact]

Ps as for the plugs.
Unless you can run fuel that has no methanol its hard to tell by color. You could richin it by doi g the C0/C1 jumper mod. It only takes few minutes. I average 44mpg w/how and where i ride, recently did a long run maintaining legal limits and achieved 66mpg! Point, the mod didnt kill the mpg.

 

[TownsendsFJR1300]

IMO even w/weak springs, set the tubes to the same height. And grab some new springs ASAP...

Sounds generally like he knew what he was doing but I agree with Randy, set the tubes equally in relation to the upper triple clamp.

One spring will be working a little harder than the other somewhat until its replaced..

Handling May be comprimised too, so I would take it easy on at least any hard leans, etc until the front end is 100%..

Re wheel droop, the forks should droop the same without the springs even installed(fully extended, even pulled by hand if need be to move some oil if present). (front end up in the air)

Just as an FYI, the triples are normally installed first, (the top nut NOT fully tightened down until everything is lined up. The fork legs then installed and the top triple and forks snugged down (everything aligned up). Once lined up, you can torque the top triple CENTER NUT, then the fork legs. The wheel, axle and brake calipers generally is set last.



I hope Randy was joking (or I misderstood);

"Also i say bend the axle but for all i know it may fracture the fork body where the axle is retained".

Do not bend anything.

That axle fits square in the lower fork legs, bending it serves no purpose short of having to replace it. Thats not even addressing the wheel bearings if the axle would even go thru, nor how it affects the wheel in relation to the brake caliper.

The forks will still work with the worn spring, just NOT as efficent as designed...

 

[FinalImpact]

Sounds generally like he knew what he was doing but I agree with Randy, set the tubes equally in relation to the upper triple clamp.

One spring will be working a little harder than the other somewhat until its replaced..

Handling May be comprimised too, so I would take it easy on at least any hard leans, etc until the front end is 100%..

Re wheel droop, the forks should droop the same without the springs even installed(fully extended, even pulled by hand if need be to move some oil if present). (front end up in the air)

Just as an FYI, the triples are normally installed first, (the top nut NOT fully tightened down until everything is lined up. The fork legs then installed and the top triple and forks snugged down (everything aligned up). Once lined up, you can torque the top triple CENTER NUT, then the fork legs. The wheel, axle and brake calipers generally is set last.



I hope Randy was joking (or I misderstood);

"Also i say bend the axle but for all i know it may fracture the fork body where the axle is retained".

Do not bend anything.

That axle fits square in the lower fork legs, bending it serves no purpose short of having to replace it. Thats not even addressing the wheel bearings if the axle would even go thru, nor how it affects the wheel in relation to the brake caliper.

The forks will still work with the worn spring, just NOT as efficent as designed...

No not kidding.... When it bottoms out it will be stressed.i don't know which component is weaker/stronger but one holds the othere therefore both will be stressed.
Make them match height, the springs will get over it...

 

[TownsendsFJR1300]

No not kidding.... When it bottoms out it will be stressed.i don't know which component is weaker/stronger but one holds the othere therefore both will be stressed.
Make them match height, the springs will get over it...

Agreed there will be unnessary stress however, keep in mind, when someone does a HIGH up wheelie and drops it, especially hard, there's a lot more stress than normal riding hitting road bumps..

The fork can only bottom out so far before it stops... In this case, it'll likely be more often.

No forks have broken where the axle joins that I've seen in 5 years here, never. And you know his is NOT the only one with a worn spring out on the road...

If the Op feels it that's serious, the bike should be parked until fixed properly.

 

[elus1ve]

Well I had absolutely no intention of leaving my fork like that. I'm definitely replacing the fork springs asap and the mechanic can get it replaced for me next Saturday but I need to place an order for the springs now.

He is offering for a pair of progressive springs that can take 186lbs before bottoming. He says I will feel a huge difference compared to my fatigued springs but it should not be far from factory settings. I couldn't find any specs on the original springs or any other springs for that matter.

Anyone has any idea if that number is good/bad? I weight in the 160lbs. I enjoy leaning on a good curve and find my current suspension gets really unstable on anything less than perfect asphalt. And I don't wheelie, at least not intentionally.

Will also be replacing the front tire and brake pads.

I'm going to keep the piston seals, brake lines for next year. Can't afford it for now.

 

[elus1ve]

So I found that the stock springs are rated at .77kg/mm and based on my weight, the recommended springs settings should be around .87kg/mm. Couldn't find anything related to total weight. Maybe I got the wrong information since I didn't get it directly from the mechanic and we know how easy it is for information to get lost in translation.

 

[TownsendsFJR1300]

I strongly suspect that worn spring is causing a good part of your suspension being un-stable... The worn front tire isn't helping any either..

The front end of mine is stone stock. I have very little chicken strips and will drag the pegs occassionally. With that said, my suspension is very stable and predictable. R6 forks / springs are supposed to help, but I really don't have any issues with the stock set up. Perhaps if I rode it harder, I would, but for me, its fine..

Re the springs. I can't speak for them (or the rates) on the FZ. Others here will chime in.


I did have them (Progressive brand springs (as recommended by the dealer) along with "All Balls" steering bearings installed in my old Goldwing years ago. For the wing, (a nice, soft, LD, mushy ride), the springs were way too hard for me. The shop adjusted the rear suspension (electric suspension) almost to the upper limits to be equal with the front end. I kept them in for awhile and hated it. Pulled them out and put the stockers back in. Back to the nice mushy ride the bike was designed to be..

 

[TownsendsFJR1300]

So I found that the stock springs are rated at .77kg/mm and based on my weight, the recommended springs settings should be around .87kg/mm. Couldn't find anything related to total weight. Maybe I got the wrong information since I didn't get it directly from the mechanic and we know how easy it is for information to get lost in translation.

If there's a "Progressive Spring" web site, I would think they would list whats available for your bike along with recommendations (if more than one spring is available). Might be worth a search...

 

[FinalImpact]

When you order new springs I'd personally stay away from dual rate or the OEM Progressive rate springs. The rear has a linear spring with a fixed rate and in my opinion keeping the ends closer to matched make the bike more predictable.

OEM:
Stock FZ6 progressive rate of:
Spring rate K1: 7.40 N/mm (42.25 lb/in) (0.75 kgf/mm)
Spring rate K2: 11.80 N/mm (67.38 lb/in) (1.20 kgf/mm)

I'm not sure what you weigh or if you ride 2 up often, but 0.85 to 0.90 would be a good starting point for single rider under 175 lbs no gear.

I'm pretty happy with the R6 forks running a linear rate like:
Spring rate K1: 8.3 N/mm (0.83 kg/mm, 46.49 lb/in)

But like everything else, opinions will vary. If your intended use is solo rider on the freeway another variable rate spring rides nice. If you're apt to track it a be more aggressive, go for a fixed single rate.

I'm thinking we beat this to death but pictures always help so here is a quick drawing of what happens when the stanchion tubes are not equal. Under basic riding the springs achieve an equal load balance with the axles help. Although the stanchion tubes are unequal, the fork bodies are held true by the axle.

On the right side of the pic, its still OK until the fork bottoms. Then depending on how badly it bottoms the fork, there is risk of axle flex and damage to the forks tubes where the axle mounts. Potentially the only thing stopping the "flex" (depending on how hard the impact), is when the other fork tube bottoms.

 

[elus1ve]

Thanks for the drawing FinalImpact. It was clear from your previous explanation but you illustrated it well. I am not sure if I ever bottomed my fork before. Maybe I did and didn't notice. So right now I am still riding with the current setup albeit more cautiously.

Also thank you guys for the input on the suspensions. I have decided to go with Racetech linear .85 or .90Kg/mm, whichever is available. From my readings so far, it would seem that this is a medium-to-firm setup. I'm around 160Lbs and I ride alone 90% of the time. 2 up with the current setup has become progressively more annoying over the last 2 years. The forks keep diving and diving on braking.

I'm don't track but like I said I enjoy leaning when the roads permit. Basically I just want to get rid of the insecure feeling I get from my bike when doing curves. I like my car's suspension to be on the firmer side so I figured my preferences for motorcycle suspension should be the same. I prefer to sacrifice a bit of comfort for the feeling that the tires stay planted on the road at all time. I'm far from being a skilled rider and the Fz6 is my first bike so educated guessing is part of my learning process.

I do hope I will like the new suspension though and I will know in a week if I picked the right firmness.