KDXRIDER.NET

Hi all

I literally have 2-3 hours on a fresh top end on my KDX. I thought I had a head gasket leak because of excess white smoke, so I replaced the base and head gaskets just now. I thought I may have installed the head gasket incorrectly.

On inspecting the cylinder, I noticed some wear around the intake and the exhaust port. I had the cylinder freshly re-plated by a professional outfit here and they also had my piston, so would have measured to spec. Thats why I'm unsure what the wear is - is this normal wear in? I didnt get this on my YZ125 from new - it looked mint each time I did a top end.

Also, when reinstalling the kips shaft, I thought the claw might be one tooth off when connecting to the KIPS shaft. Unbolted, I used a plier to twist the shaft head a bit, and I heard a springy sound almost and then the shaft now turns about 180 degrees freely - before this it felt like it was locked? Is this normal, or have I likely applied too much force and now damaged something in the case end of the actuator?

I have attached some video which should detail what I am talking about.

Cheers
tucker

Cylinder:

Hmm, that cylinder doesn't look right at all, IMO. Way too shiny. It looks like raw aluminum to me. Are you sure it's been replated?

Well, on the KIPS it's bad news. By not supporting the KIPS shaft (detailed in the service manual) you bent or broke the KIPS pin that engages the KIPS governor and must be replaced. It is located within the outer clutch cover so you need to remove the complete inner/outer clutch cover, locate the broken pin/pieces and remove it/them, and replace with a new pin, and reassemble following the procedures in the service manual.

yep, you broke it

thanks guys appreciate the parts breakdown - looks like I'm in for job. Is there a good thread on here about how to fix that? i dont have a service manual and they are very hard to come by here as must be shipped ex japan and it takes forever during covid. I had been using cyclepedia when i did the rebuild but my subscription has lapsed.

is it possible the cylinder wear is aluminum transfer from the piston to the cylinder wall? you can still see crosshatching even where it looks like its "worn". I honestly have no idea why there would be wear otherwise. I use quality fully synthetic premix at 30:1. fresh air fitler, properly installed and oiled with motorex. yes it was professionally done by NZ cylinder (they do all replating in NZ).

piston also looks decent - i.e. no signs of wear.

the reason i found i probably had a head leak was one head bolt had somehow come off after rebuild + the white smoke as mentioned. i swear i tripled checked with the torque wrench - first time this has happened to me.

It may just be some breaking in wear. It does kind of look a little different than the Millenium jobs I have seen.

Did you Loctite the studs into the cylinder?

There are a couple of threads on here about KIPS work.

Yeah I used blue loctite on the head studs - could it be one of them came a bit loose? I didn't check that when I did it again - I just put copper antiseize on my head nuts.

Sweet as.

I've read the "how to" on here and a few other threads but im having trouble removing the mechanical seal which has been pressed in. I dont have a bearing puller / driver to use and so have been trying a flathead and hammer to work it out. this has just ended up tearing the metal of the mechanical seal without pushing it out.

anyone got any tips?