KIPS center valve installation

[bultaco4ever]

Looking for some experience to help me understand what Kips is doing. I have my cyl off and will be re-installing the R and L exhaust valves and the main center exhaust valve on my '93 200E. As I understand it, the 92-94 models have a slightly different center valve than the earlier E models. My question has two parts. First, in general, is Kips raising the exhaust port at high rpms to allow gases to escape sooner and allow fuel to enter sooner in the combustion chamber? Is that an accurate description?
And secondly, regarding the '93 model, should the center valve be 'closed' when the operating rod is all the way in (low rpm) and open when the rod is pulled out (high rpm)?
Any advice on installing the center valve would be appreciated.

[gereonb]

KIPS is enlarging all three exhaust ports when over 6000rpm, I don't think it will allow anything to happen any "sooner", it just creates a better powerband with more top and bottom end power.
When you pull the rod outwards all the ports should open up.

[bultaco4ever]

Thanks...that's what I thought about the valves opening. I might debate you on the timing of the exhaust. Yes, the Kips are enlarging the opening but, isn't the larger opening higher in the cyhlinder....thus...the rings and crown of the piston pass the opening 'sooner'.

[sarrant]

Yes. Greater port duration and less compression at higher revs for more over-rev and less detonation. Greater compression at lower RPM for more torque.

The side subvalves effectively add the KIPS chamber to the pipe tuning during low revs to shift the on-the-pipe torque peak downward.

On your old Bultacos, you could port for peak power, but there would be a low-end trade off (the bike would become pipey). The Kips system allows two different exhaust portings (and two different exhaust path tunings) on the same cylinder.