Fork leak at compression adjusting screw

Discussion specific to the 1995 - 2006 KDX200 (H Series) and 1995 - 2005 KDX220R (A Series) models sold in the USA
Charles
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Fork leak at compression adjusting screw

Post by Charles »

Hello,

I just noticed a leak on my right fork. It's coming from the compression adjustment screw at the bottom. A few drops for 24h.

I looked at the parts there seems to be two gaskets: 11009-1592 and 92055-1502

Do you guys know if I can replace those easily from the outside or do I need to perform a disassembly of the fork?

I have a big ride coming in two weeks so I'm not eager to open the fork right now


Thanks
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doakley
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Re: Fork leak at compression adjusting screw

Post by doakley »

Looks like you'll have to disassemble. You will need a fork tool (search these forums) to do this but is isn't difficult. While in there you might consider doing the "shim stack modification" (search these forums again). That isn't hard either and you'll be doing 99% of it anyway to replace those little gaskets. All this assumes (ass-u-me) you are correct and the leak is around the little adjusting clicker screw and not the threads holding the lower part of the fork in place.
Charles
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Re: Fork leak at compression adjusting screw

Post by Charles »

Doakley,

I believe the leak is from around the lower valve assy. Not directly from the adjusting screw. I just checked again and cleaned the aera.

I'll check again tomorrow once it has leaked a bit, but I guess i was wrong and it seems to be around the lower valve. Inside of the 14mm hex seems to be dry..
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Re: Fork leak at compression adjusting screw

Post by Charles »

Here is a picture
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Re: Fork leak at compression adjusting screw

Post by KDXGarage »

I would disassemble it and check it out. Did someone have it apart before? There is a torque listing for it. Holding the cartridge still while it is tightened is required.
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Re: Fork leak at compression adjusting screw

Post by Charles »

I had the oil and seals replaced by a shop a few months ago.
I don't think they replaced the o-rings at the bottom valve.

I ordered the two o rings from kawasaki and some 7.5wt oil. I'm going to build the cartridge took and open the fork to replace them.
I'll probably do the shim stack mod too.
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Re: Fork leak at compression adjusting screw

Post by Charles »

I made the cartridge holder tool today.

I soldered about 80cm of pipe (20mm diameter) to an M18 nut (27mm wrench).

Now I'm just waiting for the O-rings, they're supposed to be shipped today.
While I'm at it I ordered new steering bearings, It's the only chassis bearing I have not replaced or checked yet.
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Re: Fork leak at compression adjusting screw

Post by KDXGarage »

Congratulations on stepping up and making your own tool.

The bottom portion is 14 mm hex.

Don't forget to take out the old inner races when doing the bearings. Don't just throw new bearings into old races.

Keep up the good work.
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Charles
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Re: Fork leak at compression adjusting screw

Post by Charles »

Thanks Man. Just received the bearings today from a internet bearing shop.
They were massively cheaper than the Kawasaki parts. I made sure they're the same reference, and sealed ones.
Like 13€ each. Kawasaki is asking for almost 100€ for the pair!
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Re: Fork leak at compression adjusting screw

Post by KDXGarage »

Great find on Koyo bearings!
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Re: Fork leak at compression adjusting screw

Post by Charles »

So, tonight I replaced the bearings. They were not so bad but it won't hurt to put new ones.
Removing the races was easy, and I used them to seat the new ones in place. The lower bearing on the stem was a little bit harder. I cut the bearing with a chisel then used a punch to drive the inner race out. I used it to hammer the new bearing down the stem, along with suit some 40mm PVC pipe. Packed them with good quality molybdenum grease.
I tightened the castellated nut hard a few times and backed it out, then hand-tightened it plus just a bit. Ia that correct? It is tricky because if you move the lower fee from left to right to check it out it loosens the nut..

I also disassembled the leaky fork tube. It was really easy with the tool. I inspected the lower valve assy. Turns out there is no o-ring down there, only a copper washer. Is this normal?

I performed the shim stack mod. The original peening was there so it has never been touched, and I only had 9 shims! Maybe in European bikes the stacks were different? I removed one and put the nut back. Had a sweaty moment trying not to destroy the damaged threads...
Tomorrow I'll receive the OEM o-rings (or copper gaskets??) and I will rebuild the front end.
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Re: Fork leak at compression adjusting screw

Post by Charles »

Here is a pic of the lower valve and gasket. Also the removed shim.
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Re: Fork leak at compression adjusting screw

Post by KDXGarage »

With the front end off the ground (bike on a work stand), lightly turn the bars from side to side. You will get a feel for too loose and too tight.

The forks just have one o-ring on the base valve and the copper gasket. I assume someone did not tighten it to the proper torque and/or did not change the gasket.

Image
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Re: Fork leak at compression adjusting screw

Post by Charles »

Job done!!

I finished the fork tubes! I was wrong, there were ten shims, but they are tricky to separate! I didn't have the courage to re-do the first leg so now I'm -1 shim in each leg so... "half shim stack mod". The second shim will wait until the next fork service. I cleaned up the copper gaskets seats thoroughly, they were quite dirty.

I had the stem nut very lightly torqued, the steering has no play but it is much lighter than before. Bike on the workstand with the front wheel up, the front end will fall either side on its own.
I took the time to properly align the fork tubes, and the front wheel.
Found a good tip: before tightening the four bolts that retain the axle, spin the wheel and stop it quickly with the brake. This makes the right fork leg jump into alignment.

I sat on the bike, at first the 7.5 weight oil feels a bit firm. I'll try to ride it soon. Thanks a lot for the help!!
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Re: Fork leak at compression adjusting screw

Post by KDXGarage »

Good job.

I like to have the steering take a tiny nudge to start moving.
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Re: Fork leak at compression adjusting screw

Post by Charles »

Does it make a big difference?

I always thought that my bike was "lively" on the front end and did not track the terrain well especially on rocky roads.
My wife's Huqvarna WRE, which is an old bike too (99), feels much more stable and planted, like it's on rails.
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Re: Fork leak at compression adjusting screw

Post by KDXGarage »

I am not sure on the difference. I think some manual once mentioned the nut torque spec at 35 inch pounds. I just do it by feel.
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Re: Fork leak at compression adjusting screw

Post by doakley »

I do mine by feel also and tend to lean towards the tighter side, not tight, I just prefer the front end not fall over too easily. I believe the front end can be a little "twitchy" or "lively" if a bit loose.
Maybe just my imagination but anything that increases my confidence in the bike setup is a good thing to me.
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Re: Fork leak at compression adjusting screw

Post by Charles »

Thank you for your inputs guys.

I did my first "real" enduro ride, it was a 180km (111Miles) ride across very difficults terrains, the hardest parts were the wet black rocks we find in our volcanic environment. I really struggled in the muddy trails going uphill full of those big splippery rocks, but it was mainly my lack of technique.

The bike did behave really well, no leaks or weird handling. I was able to ride it very fast in the trails, without the front end acting weird. The half shim stack mod proved beneficial, I'll definitely remove one more shim during the next fork service.
7.5wt oil acted as a band-aid for spring replacement but is definitely not a long-term solution. I really need to find new springs.

I had the opportunity to swap bikes for an hour with a very good rider who was training for the big local race next year (The "Rand'Auvergne"). I was astonished seeing how fast he was with the old KDX. I saw my green bike just flying through gnarly stuff.
In the end he thought the bike was very good, but needed "fork springs a little bit stiffer". I guess it's no surprise! He really liked the overall smoothness of the bike.
Meanwhile I was riding on his 2020 KTM 250F, and had a great time! The WP suspensions makes the bike so comfortable, filtering every bump and rocks, while still remaining firm. The engine was marvelous, always manageable, with a very consistent power delivery through all RPMs. All the power control is in the right handle, very smooth on the first half, making it easy to find traction. And when you get past that point the engine opens up and pulls nicely while still being manageable. I'm a two-stroke lover but this was definitely a sweet time.
The first thing I shouted at him after a few minutes on his bike was: "This is not a dirt bike! This is a HUG!"

When we swapped back, I was afraid to be deceived by the comparison, but I wasn't! The position on the KDX felt just as natural, the controls were just as smooth. The engine, while obviously being less modern, was nothing close to weak or brutal. The major drawback was the front forks but with my current level, it's definitely the technique which is holding me back.
Ah, and also the electric start, while less flamboyant than the kick, really makes a difference over the course of a dawn to dusk ride.

I'm just so in love with my KDX now! Setting it up properly, getting some good coaching from proper riders and a long, (very) hard day of practice was all it took!

Next step will definitely be fork springs, but racetech imported stuff is crazy expensive here, I'll probably have to find an european source. Or a complete front end, but same problem, used parts are overpriced, and I liked that the stock forks were so easy to work on.

Also, having ridden a "new" bike, in my opinion it is DEFINITELY worth the money to upgrade the KDX with a better front end.
I'd to this instead of buying a 2000-20010 bike.
I think replacing the bike is only worth it if you get a new-gen, fuel injected, very nicely suspended and electric-starter equipped dirt bike. Anything less than that, you'll be getting not much improvement from your old rusty KDX.

:supz:
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Re: Fork leak at compression adjusting screw

Post by KDXGarage »

MAN! 111 miles!

Congratulations on getting out there and learning with your KDX.

I think K Tech may be a brand of springs or company over there.
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