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While tearing down my E model, I stumbled across something that may apply to a few of you.
Upon removing the head, I discovered a sleeve,- groovy,I thought -cheap rebuild. Then I attempted to remove the kips valves. Two days later, intermittently spraying various solvents, I was able to remove the center one. The left one was free, but but not removable yet.I could not move the shaft - the idler and right valve would not budge. Three days of carb cleaner and gentle persuasion later I decided to pry out the shaft bushing. I was now able to remove the shaft, and left valve.
bending a couple 1/8" screwdrivers into mini pry bars, I was able to get under both sides of the idler gear. through the bushing hole,
and this should've worked.
But no dice.
Frustrated, I tried a small channellock plier on the idler gear, and broke it.
Now I attempted to lift the right valve out. But no luck. Chipped a tooth on the gear. Now the valve was stuck in the bottom of the hole. I knew by looking at the other valve, that I could drill the center out till I hit the valve cut-away,and lift it out with a home made mini-slidehammer. After spraying more solvent through the hole, I was able to remove the valve.
I cleaned up the spooge and tested the valves fit, and find that if installed, that it would still bind . The spooge wasn't all that bad.
So I got to thinking about the sleeves close proximity to the valve.I then measured the I.D. of the KIPS well,and found it slightly egg-shaped. My thinking is that when Sleeve was installed, that the installer may have overdone the interference fit and distorted the kips.
If I re-use this jug, I may try and clearance the well with a brake hone.
Any ideas?

Ahh, those E series KIPS valves.

It's definitely worth a try to clean up the valve bores to get a nice slip fit, but I wonder if the impinging iron sleeve will cut much harder than the aluminum of the cylinder, causing you to just hog out the aluminum rather than the iron. If so, it might be tough to get those sub valve bores nice and round and in the right place.

My personal vote is to force the broken sub valves back down into the bores in the open position and leave them permanently open! Or just leave them out completely and bore out that sleeve to 240cc to get some of the lost low end back. Voila! No more broken KIPS valves.

(I'm only sort of kidding about ditching those valves. I'm about to do this the next time I have a broken set to deal with.)

BTW, "Cheap Rebuild" goes to the plated cyl as long as it's not scored. A sleeve needs a bore job every time.

I have a sleeved cylinder. Nothing wrong with that at all. And at rebuild time, it never needs plating. Just hone and go.

I have no problem with the sleeve. It doesn't protrude into the KIPS well,
But its close. I suspect, as stated before, that I think Its a sleeve install problem.
I will buy the next oversize "Pro-X 66.50" and have it honed. Will clearance the KIPS and buy new parts.
My guess is that the pre-P.O. rebuilt the top end with new parts , bore, and new KIPS parts, discovered the KIPS was binding ,and removed the actuator arm. Then he lost interest and let it sit for awhile. Then sold the bike.
Then P.O. bought the bike as a beater ride. Of course the carb needed cleaning! Which he did, neglecting to install a main jet.Then he got discouraged and sold it to me.
Stupid yours truelly examined bike, noting that it started easily W/good compression. Then upon riding noticed a huge bog- followed by a short but relatively strong hit. I thought, no big deal.
I took it home and rode about 5 minutes before $--t hit the fan. A loud knocking noise erupted, my son, who was following on his XR70 said flame came from the tailpipe.
Tearing it down, it seems something metal went through the top end.
I have no idea what. The piston and head are hammered. As well as several other things, rearing their ugly heads. Its hard stay stoic and on track when the off-season
is offering better deals everyday.Just saw a cherry 02' RM 250 for $800. I feel like Capn. Kirk slapping himself.
Could this be some form of payback? Should I get existential about this?