KDXRIDER.NET

Hey guys, but if a story to explain but here we go.

I've got a 1990, only issue it had when I bought it was second gear skips, and the kick starter was slipping. After reading online to use atf+4. So I tried that and issue was solved. I went for about 3 rides, all good. Changed the fluid again. New atf+4.
Next ride was fine, but as the ride went on it started getting harder and harder to find neutral and shifting between first and second started to take a lot of effort.

The clutch does drag quite a bit. I thought maybe something odd happened in there so did some investigating. Nothing was out of the ordinary. Checked the parts diagram. Everything is there and correct. Put it back together. New atf fluid again. Test ride and same problem.

Took it all apart thinking something was going on with the shift mechanism that's behind the clutch. Rear wheel up, it was having the same issue, I was spinning the wheel while shifting.

So then I started to think the shift forks are maybe worn or something. But on that 1 ride it went from fine to really hard to shift in like 2 hours. And too be honest most of the ride Im in second gear and not shifting a lot. So I doubt they wore so much just that ride.

So then I thought maybe it's the atf? I put some rotella 15w40 in cuz that's what I had on hand. Rode around the yard a bit and it slowly started getting better. And now it shifts fine and finds neutral quite easily.

Thoughts? Cuz I see people use atf for hard shifting kdx's. But mine seems the opposite? I'm guessing maybe the first atf change was ok cuz it had whatever left over oil on the bottom of the case still in there maybe? Maybe the shift forks like the thicker oil? I dunno.

Yes, ATF is sometimes used but I have never heard of anyone using, or recommending, specifically ATF+4.

All ATF fluids have various friction modifiers and detergents in them and maybe what's in ATF+4 doesn't play well with our type of clutch. The type of ATF normally recommended is ATF Type F used in very old Ford automatic transmissions. Even Dexron III can work but slips a little more than I like.

I use ATF type F nowadays because my kickstarter was slipping. Neutral can be a bit of a pain to find while running, though. I also replaced the spring behind the rachet mechanism for the kickstart and that completely fixed my kickstart slip problem. I can kick it however hard I want and it will not slip.
I haven't tried Rotella since I fixed it, but I may put it in next oil change, as that's what all of my other bikes get. Again, neutral can be a pain to find while running, and ATF may be the reason. I need to mess with my clutch as well, I may just not have the cable set where it needs to be.

Give Type F a try, it's the only one I have read that people use in their transmissions in terms of ATF.

Oh, and from what I've read these bikes tend to always drag a bit. Mine does, but it doesn't drag too bad, it drops a couple hundred RPM at idle when i put it into first, but doesn't move on me.

Oh ok maybe I used the wrong atf then.

When I first click into 1st gear from neutral The RPM does drop a bit which is normal. All my dirt bikes do that. But if I'm already in first then I come to a stop pull the clutch in, the rpm will drop and the bike will stall. I have to rev it once I pull the clutch to get the discs to unstick I guess haha. Kinda of annoying.

Is your clutch basket notched?

SS109 wrote: 12:25 pm Aug 01 2025 Is your clutch basket notched?

Aren't they all by now? lol

Julien D wrote: 11:49 am Aug 03 2025

SS109 wrote: 12:25 pm Aug 01 2025 Is your clutch basket notched?

Aren't they all by now? lol

Yep! I would bet any OEM basket, unless a nearly zero hour, NIB, one like Kaplan had, has notches or has been filed.

Wiseco and Mitaka both make clutch baskets for the 95-06 KDX, Mitaka make one for the 89-94... I would highly recommend buying up one of those, for basically every KDX owner, because they're going to need one at some point soon if not a long time ago, and who knows how long we'll have these readily available. There are workarounds, but it involves more skilled labor dollars...

As far as the original topic is, yes, different oils have different additives and will cause differing amounts of clutch drag as well as clutch swell. Once the friction lining is on the clutch friction discs are completely saturated with a certain type of gearbox oil, it may exhibit these symptoms for quite a while even after changing back to Rotella or a motorcycle specific wet clutch friendly oil. On a 4-stroke, getting gasoline into your oil from a flooding engine with gas getting past the piston rings will definitely make the clutch friction linings toast...

Hinson used to make one for 1995+. That is one of the "we used to have it good, and now it's gone" aftermarket parts of yesteryear.

Sorry. I will stop with the "Gather around, children" old people talk. :-)

Is there a difference in quality between the Mitaka and ProX clutch baskets? It looks like both are available for 89-94 bikes.

Guffer wrote: 11:30 am Sep 05 2025 Is there a difference in quality between the Mitaka and ProX clutch baskets? It looks like both are available for 89-94 bikes.

Those are very similar in quality and I believe they are both 7075 billet machined aluminum and both are definitely hard anodized.

Pro X advertises a Teflon coating, Mitaka is said to have some sort of low friction coating.

Wiseco is the only one that advertises a forged aluminum clutch basket that is then of course machined to tolerances, and the aluminum material is supposedly harder than the rest. Wiseco also hard anodizes on top of that and has a Teflon coating. Wiseco only makes baskets for the 220 & 200H, however.

Pro X only makes them for the 200E.

Mitaka makes two different baskets to span the entire range of water cooled KDX 200 and 220.