Whats up with my suspension?? and power??

2622 Views 15 Replies 5 Participants Last post by paul4wolves, Aug 8, 2017

paul4wolves

Discussion Starter · Jul 25, 2017

Hi All,

I've had my ZX10R for 6 months odd now and love it however I've encountered a few issues.

So I took it for MOT yesterday and it failed :crying: The suspension goes down when you push it down however it only creeps back up slowly, you can also see that it has bottomed out at some point too. The one fork seal is weeping. what is the likely cause of this before I tear it apart tomorrow, are the spring prone to weakening or maybe the bushes or seal is causing a bit of stiction?

The other issue is... the engine pulls fine to about 8k rpm then feel like its stuttering all the way to red line (this is intermittent) the pick picks up when you let off the throttle.. I've got my money on the fuel pump or filter (I removed the pump before and blew the filter which had quite a bit of resistance however the pump and tank were spotless).

Was thinking of removing the black fuel pump filter and fitting an inline fuel filter, can that be easily done with a bit of tubing?

So all in all... I have a slow bike that handles like a plank of wood.

all help appreciated

1 - 16 of 16 Posts

paul4wolves

Discussion Starter · #2 · Jul 25, 2017

ZX10R 05 model with 38k on the clock, as far as the documents go it doesn't have any work done on the suspension, springs etc

JayBoCC2

· #3 · Jul 25, 2017

that thing is in dire need of a full suspension service. Rear shock probably has no gas left in it, and the oil probably looks like mud. The front forks also probably look like mud in addition to losing oil through the seals. Around here you can get both serviced for about $500 total.

No need for an inline filter. Im not sure about the sputtering but you could try removing the pump and cleaning the pickup. Personally i'd start with all the basic maintenance items like plugs, valve adjustment, air filter, suspension service.

paul4wolves

Discussion Starter · #4 · Jul 25, 2017

Thanks for your response, Will have a look into it, the rear shock is aftermarket and will take the legs off and have a look.

I've tried the plugs, air filter, not looked at the valves yet. I tested to see how much fuel the pump supplied and it produced about 78ml in the 4 seconds (just over the specified 76ml in the manual) I thought the filter may be causing the pump to struggle as it may be clogged up?

evallarta1

· #5 · Jul 25, 2017

paul4wolves said:
Hi All,

I've had my ZX10R for 6 months odd now and love it however I've encountered a few issues.

So I took it for MOT yesterday and it failed :crying: The suspension goes down when you push it down however it only creeps back up slowly, you can also see that it has bottomed out at some point too. The one fork seal is weeping. what is the likely cause of this before I tear it apart tomorrow, are the spring prone to weakening or maybe the bushes or seal is causing a bit of stiction?

A blown shock will not "creep". It will have zero damping and will pogo when pushed on. Stiction will also not creep, it will jump up the fork as stiction is not a constant. It sounds like the rebound may be all the way closed. A quick check is open the rebound all the way and see if the fork starts to move. Too much rebound can also help the fork bottom easier. Start with the easy stuff first, then move more in depth. If the bushing was an issue you would see grooves on your lower tubes and hear the grinding when you pushed on the forks.

A weeping seal could be caused by any number of things. You could try cleaning out the seals and see if that helps, but otherwise you'll want to change them. Keep in mind oil coming out of the fork is not the issue. If/when the oil hits your brake pads you will have zero stopping power and you'll have bigger issues than a leaky seal.

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Reactions: 1

paul4wolves

Discussion Starter · #6 · Jul 26, 2017

Right, so I've backed all the adjustments off on the forks and it moves a bit more freely however now when I pump hard I can hear a metal on metal sound and thr suspension still isn't right, I'm assuming the bushes are toast and I've rang Kawasaki and they said they come with the stantion

evallarta1

· #7 · Jul 26, 2017

paul4wolves said:
Right, so I've backed all the adjustments off on the forks and it moves a bit more freely however now when I pump hard I can hear a metal on metal sound and thr suspension still isn't right, I'm assuming the bushes are toast and I've rang Kawasaki and they said they come with the stantion

Correct, the bushings are pressed in the tube. But before you worry about the bushings pull the forks apart and see what is rubbing. It could be something simple.

Also the scrapping sound COULD just be the springs rubbing against the inside of the tube. This is a fairly common issue because the spring shifts and is not centered in the fork tube.

paul4wolves

Discussion Starter · #8 · Jul 27, 2017

I've pulled the forks off and had a look but not got a compression tool to get the springs out but they seem to go up and down fine now however I took it for MOT again and the chap said they still are too stiff, as far as I can see theyre ok but they are fully backed off on all the adjusters. When I pulled the forks out I tipped the fork oil out and out came about 350ml without taking the springs out. I could almost bottom them out when jumping on them (90kg bloke) so topped them up with a bit more fork oil which made it more difficult to bottom out. still the issue now is "they are still too stiff" bit annoying as I don't think theyre that bad? at a loss apart from taking them to another mot centre to see what they think.

paul4wolves

Discussion Starter · #9 · Jul 27, 2017

Also the metal on metal sound I thought I was hearing sounds to be the fork oil moving in the bottom of the fork leg when I jump on the forks and when they come back up.. so I think that might be normal, theres a few lines on the chrome where the fork goes into the leg but I don't think that would make it that stiff to fail an mot? who knows

paul4wolves

Discussion Starter · #10 · Jul 27, 2017

might just put some thinner fork oil in?

evallarta1

· #11 · Jul 27, 2017

I don't want to sound like an ass but you are starting to travel down a dangerous road with your inexperience and get yourself hurt. By emptying the forks you have taken out the air gap which would allow you to bottom the fork. But now the cartridge is close to if not empty, nullifying your damping. The cartridge MUST be immersed in oil to be effective. So without doing a proper service you have no idea where that level is.

Thinner oil will does not affect spring position, oil level does.

And I have never heard of a failed inspection because suspension is too stiff. I could see the leaking seal, but not because of wrong springs.

Reactions: 1

NinjaLife

· #12 · Jul 27, 2017

In my 7 years of riding, I've noticed that bikes generally will handle like a plank of wood when the tires are really low on air, at least that's the only time I've experienced the handling like a plank of wood.

Also, your bike doesn't have any lowering links on it does it? That can definitely contribute to the plank of wood feeling.

One other thing, it could be time for a suspension refresh like others stated, I experienced this not too long ago with our 1st gen, it had leaky fork seals and handled terribly, after new fluid and fork seals the bike seemed to handle almost as good as bike with stock links.

JayBoCC2

· #13 · Jul 27, 2017

$500 for piece of mind and guarantees that your suspension is in 100% tip top condition. Take your bike in and have a professional suspension shop service the forks and shock and be done with it. It will be like night and day.

Capncalyx

· #14 · Jul 27, 2017

Sounds like yer rebound is "packing up" dude. Adjust it so its not so slow. Sounds like its super slow right now. I have my so its pretty fast but you dont want a pogo effect either. Absolutely a novice myself here so apologies if im talking out my ass. Dont be afraid to mess with your suspension adjustments! Do one at a time though, but try combining your rebound adjusting along with compression. You have some good advice from a couple suspension pros on here, id take it.

paul4wolves

Discussion Starter · #15 · Jul 31, 2017

So I'll do a little update.. after playing with the compression and rebound settings, to my untrained eye, it seemed fine to me, I took it back to the mot place And they still weren't happy saying it needs an overhaul, so took it to another mot place for a second opinion and asked what they thought of the forks... Low and behold.. they said it was fine... So got my not done there instead. Seems to be handling better now,so it just needed adjusting as the oil didn't make much difference, thanks all. I think the first mot place may have been stricter to your for some work. Also th advisories were different, just shows the difference between MOT testers

Reactions: 1

paul4wolves

Discussion Starter · #16 · Aug 8, 2017

got to the bottom of the lack of top end power too... for anyone who is experiencing similar issues.. GET A NEW FUEL PUMP, I tore my tank apart and the tank was spotless inside, the pump looked new (may have been changed) filter probably wasn't changed which put stress on the pump to squeeze fuel through the dirty filter.. anyway.. its running perfectly again. there is a filter at the foot (little mesh thing) and the black thing attached to the pump is also a filter (which apparently causes the issues - not confirmed..)

so worth getting one off ebay to try at least, doesn't take long either

thanks all

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