Kips binding at full open... sometimes

[TheScrambler]

I have a strange issue with the kips system going on right now, wondering if anyone else has encountered this. I have a freshly millenium replated and bead blasted 92 cylinder, brand new bdk subvalves, have cleaned the main valve and rack much as I can. There's nothing in the teeth to cause binding. I have it all timed properly, and with the cylinder on the bench I can rapidly open and close the valves as many times as I want with no issue. However, as soon as I pick the cylinder up to look into the exhaust port (It's tilted slightly backward at this point) it binds at full open, and I have to wiggle the rod in and out a little bit at a time to get it to close again.

Has anyone else ever run into this? I'm wondering if the bead blasting peened the rack bore slightly and one of the little alignment cutaways is hanging up on a burr. The main valve cap and retaining clip is in place while trying this, by the way.

[KDXGarage]

Did you do the bead blasting? Do they normally do that? I was under the impression they just dipped it to remove the previous coating which removed paint also.

Did you use a lubricant during assembly?

Any chance there is plating buildup within the valve bore area? I have heard of this before.

[TheScrambler]

I wish they dipped them, but the surface finish appears bead blasted to me. It was done at millenium. I put a healthy amount of klotz techniplate on anything that moves, it must be that center bore. Guss I'l take it back apart and have a closer look in there. Just strange to me that it only does it depending on the angle that gravity is acting on it.

[bufftester]

If it happens when you tip the cylinder back (exhaust port up) I would thoroughly examine the linkage to the main valve and the main valve/seat area. Less likely a bore issue, the main valve lies at an angle in the cylinder

[TheScrambler]

Problem solved, and what I found strengthens my theory that they media blast the cylinders.

First, I tried the rod in the cylinder alone, with the top hat shaped travel limiter: moves freely. Then, with just the subvalves: still moves freely. Then, the main valve alone: binds.

It turns out that the area where the main valve fits into the cylinder has extremely thin edges, almost knife edges. One of those was catching on the matching cutaway of the main valve itself. A little massaging with a file and it spins freely now.

I think in the process of blasting, that very thin edge of the main valve bore got peened over just enough to catch the valve. I know it wasn't like that before I took it apart. Even with a broken left valve, the main and right subvalve were moving freely.

Only problem now is that I have to wash the cylinder again

[Molly's 70]

Hot soap & water is my favorite.

[bufftester]

That's kind of what I thought might be going on there. Glad you got it straightened out. Millenium used to dip everything, wonder if it was a cost cutting measure to go to bead blasting?