89 KX125 KIPS & other help needed.

[Nathan S]

So... I bought the bike with the top end in a box. Its going back together now and mostly drama-free.

But something I realise that I don't know: When the powervalve opens up, does it move the shaft to the left, or to the right?
I had been assuming that it moves to the right to open the valves, but when I've put the barrel back on, the arm (that comes out of the cases) is a long way away from the end of the shaft.
Further inspection shows that if you set the valves up differently, then they'd still work if the shaft actually moves to the left.

Same basic motor as 88 KX125 and (I believe) 90/91 KX125 and 89~96 KDX200, FWIW.

[Slakewell]

It's been a while since I owned one. I think there some timing dots on the little gears that must line up. Put the piston at BDC head off and pulling the rod out should open the vales. Now the arm that pulls the rod might be able to be 180 out but you notice this as soon as it starts.

[evo550]

Yep,
I'm with slakewell, timing marks on the shaft line up with timing marks on each valve cog.
Valves should be closed when bike not running.......if it's the same system as the '87 250's.
I believe I have a 1990 manual somewhere, I could look up and confirm if you need.

[GMC]

I think it will be all too hard for you Nathan,
best you just sell the whole thing to me

[Slakewell]

Ok try this
Have just been through this with the kdx 200 which is the same.
The powervalves must be closed when the shaft is pushed left, or into the cylinder. There are some dots to line up but you can work it out if they are hard to find. They are then open when the shaft is pulled out to the stop on the side of the cylinder.The right side bush is also the travel limiter for the shaft.
Adjust the operating lever from the gearbox to the cylinder in the closed position. The trap to the whole setup, the 10mm head on the 6mm shaft is left hand thread. If the lever has to be adjusted don`t undo the nut like normal or you will wreck the shaft coming up from the gearbox. Be warned, left hand thread.
Run the bike with the pipe off and the left hand kips cover off to check operation. At low revs the exhaust manifold is open to the chamber which now has the cover off, rev it and the chamber will block off as the shaft moves to the right. Hope this makes sense and is helpful.

[Nathan S]

Makes perfect sense, thanks Slakewell.
It also means that I did it right, which also makes me happy.

[Nathan S]

It starts and runs. 

[Slakewell]

Great , now could you please find me a nice YZ front hub and post it to me please 

[Nathan S]

Nice might be a challenge, but definitely have something to get you out of trouble.

Have you really not been anywhere near a phone for three weeks? 04000 23847

[Slakewell]

I used to love my little KX.
Phone involes telstra the ombudsman and the same horry story most of us have.

[Nathan S]

So it starts easily, and runs well in the bottom end.

That's where the good news ends... Its got a significant air leak that's more than a loose hose clamp or similar. It also pops and carries on when you oper it up, although I'm not too stressed about that until the KIPS is working properly and the air leak is fixed.

What's really worrying me is the gearbox. If you change up from first, it goes straight to third gear. Down from third, you usually find neutral, although you can get second if you're careful.

Before I rip is apart, does anyone have any suggestions of what to look for?

Despite the hassles, it threatens to be one of those kick-arse bikes - the vibe is good and what I've seen so far impresses me.

[Slakewell]

I maybe wrong but some bikes have timing marks on the selector drum  I never did pull my KX apart much except for one piston and a few sets of rings.
I think you can see the timing marks when you pull the shift drum spring tension detent out?