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I finally received my KIPS valves for my 1992 KDX SR. I found a machine shop that could make me a spare set of vales from steel.

The OEM aluminium ones (they feel so light and flimsy... Also have casting marks). No wonder they always break...



The steel ones I just had made:


Side by side:





The process (took a bit under two days as they were really busy with obviously "bigger" clients):





However, I just noticed last night that they're a bit off... The groove in the middle of the "thick" section is off. So I'm going to go back today and ask them to redo them. I'm putting the originals in the engine because I'm really itching for a ride this Sunday (I've been waiting almost a month for a few parts). The copies are pretty darn good. I don't have a set of calipers, but the gears are positioned exactly the same (and have the same length). The two little protruding bits at each end are a tad longer than original, but I can just file those off a bit. The thick body itself also looks maybe half a mm longer. Might bring them back and have them shave off a bit, not sure if the kips fit really tight and need to be exact, or if they've got a bit of movement and set in grease. Anyways, to see what I mean regarding the "chunk in the middle being off", have a look here:







Either way, total damage was 30$ after some bargaining (for the set). I could get some made for other people if anyone's interested. I figure if there's a group/bulk buy, I could bring him down to 10-12$ each (so 20-25$ for a set)+shipping. Now I know these aren't OEM, so I'd definitely like it if someone had a look at them and told me what they thought. Would steel mess up the other gears involved? Do KIPS valves need to be really precise/CNC, or is there a bit of "play"? What would that groove in the middle being off mean? The KIPS wouldn't fully open/close? I've seen/heard of other people getting steel ones made (or making their own). I could get other types of KIPS made (older 80s KIPS, 95+ KIPS), but I'd obviously need an original set to give them beforehand.

looks interesting probably need to make the idle gear also out of steel. Keep us posted. Just put in a new set in my 89 after the right one broke.

WOW man very cool! I was considering doing this myself. I just purchased a new LH valve and was thinking about taking them to a shop to see if they could replicate it. But you have both there, not including the idle gear

The cutaway "groove" in the middle is the port valving and they do specifically line up with porting in cylinder casting. That could easily be corrected by just taking some more out of the bottom of those. I'd be most concerned about the cylindrical part(thick part) being as close as possible in diameter and the gear teeth on the valves meshing properly with the operation rod.

But they look really close, like WOW like this has me giddy! I am 100% interested! Keep us posted and definitely if you can get an idle gear made as well the set would be complete

Upon reading this, I immediately went to BikeBandit to check part numbers...hoping that these were common to the KDX250-D series. Alas, no...sigh.

Awesome looking project and product.

WOW!! Great job!!

Do you know what the Kawasaki part nuber is for them?

Im VERY interested in a set once the troubleshooting is sorted out and those valves are precise. Sign me up!

how do the original valves fail . is it just the gear that gets stripped ? it may be easier and cheaper to just replace the gear teeth section with a steel part . machine off the old gear and press on the new one .
it is a top idea though .

I am really very interested for my 93!
sending to France is possible?

I would defiantly be interested in a set of those for my 94 once the final product is finished.

I dont have an E series so I am not familiar with them, but what exactly causes the aluminum valves to fail? Something has to bind and the valve is then the weak link?

If you beef up the valve to steel and the valve binds again, what is the next weak link(if there is one)? I was wondering if the design flaw isnt that the valves are made of soft aluminum but something else.

Very cool that you took the initiative and had a set made. I was surprised at how little the shop charged though. That might explain why some of the dimensions are off.

The 89-94 uses a single rod to operate all 4 different gears(including idle/reverse gear on RH side). They don't bind, they just wear out over time. And by over time (at least in my experience) I mean about 10-15 hours! I pulled this brand new gear out of mine a couple months ago with about half a season on it. No neglect / lubrication issues, it's just the type of aluminum alloy they are made from.



Eventually that becomes:

(the valve from my motor when I bought it)

A loose and stripped gear like that could cause binding, however



Some of the worst cases I've seen look like this:

Gotanubike, did you replace the steel rod when you replaced the gears?

No that part is dico'd and very hard to find. I had a spare but I shipped out out to another member in need of one. It is made out of steel like the center valve. I think I checked it by rolling it across a flat surface.

Please, convince the machine shop you're using to sell variants for all of the KX/KDX models that use this mechanical arrangement. I'd buy two sets for my KDX250, to have them and support the effort. I'm sure they'd sell like hotcakes on the KX/Evo-moto/thumpertalk forums.

I'd be down for a set.

Jason wrote:WOW!! Great job!!

Do you know what the Kawasaki part nuber is for them?

Check out http://www.mrcycles.com/page/oemdirectory

They have all the part numbers etc. for most Japanese bikes.

Thanks, but he has an SR model. I don't know if his valves are the same as 1989 - 1994 USA KDX valves. If his valves are different, then all these posts and time are worthless to USA KDX owners.

Jason wrote:Thanks, but he has an SR model. I don't know if his valves are the same as 1989 - 1994 USA KDX valves. If his valves are different, then all these posts and time are worthless to USA KDX owners.

I totally missed that he wasnt in the US. I guess that might explain how little the machine shop was charging.

I'm willing to bet they are the same.

If Bitteeinit chimes in here maybe he could tell us the part number by which he ordered the Kawasaki valves. That would confirm it but they look identical to American ones.

If they do in fact fit the E-series then I would be down for a couple of sets.

BTW, I have my own belief on why some KIPS fail while others don't have any problems. I believe it is due to core shift of the cylinder. Anyone who has played with very high performance V8's (1000+ HP) knows that core shift will determine to what extent a cylinder can be bored and what HP it can handle. Anyways, I believe the bikes that have KIPS issues are, in part, due to this core shift and, when combined with the cast aluminum subvalves, it creates a sort of mismatch of the gears and/or binding causing them to strip the teeth and/or break the subvalve. Eh, just a theory!