KX125 1991 KIPS VALVES

[Davey Crocket]

Does anyone know if the Kips valves are interchangeable on the 88/89 to the 90/91 models....90/91 is the same P/N, 88 is different number and 89 different again....they are almost impossible to get in good nick or NOS so I was looking at making some [90/91] sets up. They are basically the same engine family with slightly different barrels/heads. If they are interchangeable then I would get more made and they would be cheaper. Any help would be appreciated, cheers John.

[GMC]

87 is different again as I think 86 is too
I have an untested theory that a lot of these valves are the same size and it is just the port cutout that varies as they were changing port timing most years.

I will one day be chasing some for either an 88 or 89 125 myself, depending on what barrel i end up running with.

Can measure up an 88 one if you want, I know one is good and the other broken.
Been going to compare them with the 86-88 KDX 200 as well as they are also similar

[Lozza]

I have an 89 here I'll post a pic. I doubt the cutouts are much different Geoff the KIPS isn't a port timing device it just blocks the sub exhaust and opens the path to the resonator. KR-1 valves were successfully remanufactured a few years ago. They were hard anodised with a slippery coating to minimise the chances of the seizing up.

[Davey Crocket]

I wouldn't be surprised if they where the same...88-91....but numbers change....it would be good to compare lengths etc.....old mate in the UK makes them for KR's and a KMX200....sort of a trailbike version of a KDX..[DT200R]....they are different though....it would be good if you could make one that fitted all of those series engines....KX125/KDX200.

[GMC]

I doubt the cutouts are much different Geoff the KIPS isn't a port timing device it just blocks the sub exhaust and opens the path to the resonator.

While the valve itself doesn't effect port timing I am running with the theory that those sub exhaust ports vary in height over the year models therefore the tract they use to open into the main exhaust port would vary meaning different cutouts to suit the different exhaust tracts.

My guess is that you may be able to make the cutout a bit taller therefore suiting more models at the expense of  a bit of turbulence due to cutout not matching the port exactly.
Of course some dimensions from different models are needed to find out exactly what Kawasaki changed over the years.