Kips question

[lr172]

I had the exhaust off of my "new to me" '00 KDX the other day when adding the new reeds, so I took a look inside the exhaust port. The Kips valve didn't look too mucked up with carbon, but I was curious if it was stuck. So, I took off the small round access plug on the left side of the engine and turned the nut on the end of the Kips shaft to confirm the assembly moved freely. It moved quite easilly and without resistance and I could see the valve move.

I didn't turn it very much, just enough to see it was moving. I thought about it afterwards and wondered if it should have moved if the complete linkage was intact.

Does anyone know if I should be able to move the valve slightly if the linkage is fully connected? I have now seen some postings stating to remove the gear before testing the motion.


The second thing that I saw were three vertical lines on the piston. They looked more like wearing than scrtches, however they were narrow and very obvious. The ring appeared to be in good shape. Does this mean that I should get to the job of doing the Top End pretty soon?

Thanks for your assistance.

 

[strider80]

I think you are okay on the KIPS. It is a centrifugal weighted assembly that is not directly connected to the crankshaft. Hopefully I am not off base here??? Maybe someone else will chime in.

 

[canyncarvr]

Re:'Does anyone know if I should be able to move the valve slightly if the linkage is fully connected? I have now seen some postings stating to remove the gear before testing the motion.'

Yes you can. Well, not only move it slightly, but thru its full range of movement. You do not need to remove the gear before testing the motion.

Can you hurt it that way? Sure!! Put a 1/2-drive breaker bar on it and crank it to about 80ft/lbs.

A BTW...but never NEVER take off the gear (claw, whatever) from the activating shaft on the RH side without supporting that shaft. The nut is LHT, too. There is a flat on the shaft for the express purpose of placing a wrench there (for support).

If you don't do that, chances are excellent you will break the pin off at the bottom of the shaft. Subsequent complete and total destruction may occur thereafter.

Really!

THE ring? If you only saw one, it's very much time for a rebuild!! :whoa:

Scoring is never a good thing on a piston. Best to have absolutely none, but not uncommon to have some.

So...I guess it kind'a depends!!

 

[lr172]

Thanks for the reply and the warnings. I was happy to see that the Kips moved easily after reading all the stories about them getting stuck.

 

[canyncarvr]

BTW, regarding: 'and I could see the valve move.'

THE valve? That's not generally what you need to worry about assuming you're referring to the main valve. It's the subport drums on either side that are more often goobered.

Verify that they are moving AND timed correctly. There is a good write-up in the service manual complete with drawings that clearly show what's going on when if you don't know, also an animation on CDave's site that's good. Recognize that the longer that animation runs, the more out of 'sync' it tends to get, until it's exactly backwards..but you will get the idea: High RPM = more port, low RPM = less port.

 

[blackduc98]

It is easy to observe movement of left sub-port drum. Remove the resonator cover (that's the rectangular cover that says KIPS on it). At low rpm the passage to resonator chamber should be open, and at high rpm it should be closed. Don't do this with a running engine of course.

BTW, I fiddled with timing of my sub-port valves, and I ended up timing them exactly like it shows in the factory manual. You can only adjust it in whole-tooth steps, so fine alignment is impossible, which leaves me a little dissatisfied with how my subport valves align with the passages. Or am I missing some trick here?

 

[canyncarvr]

Not that I know of.

'As they should be' does leave something to be desired.

Well, that I've seen anyway. I have replaced different pieces here and there, but never EVERYthing new at the SAME time.

Maybe some of the less the perfect alignment is due to some new parts integrated with some old.

But I doubt it. There isn't that much slop/wear going on. At least not in the parts I was dealing with.