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1994 R1100RS Stuck Rocker Arm Shaft

hillbillync

New member
I'm trying to resurrect a 94 R1100RS that I bought as a project that had "a rough idle" as stated from the upstanding citizen I bought it from. Turns out, these bikes will idle roughly when one cylinder had zero compression due to bent exhaust valves from over revving. Who knew? I took off the heads and had the valves checked / replaced along with a valve job on all 8 since it was a good time.

My problem is this: While attempting to reinstall the heads, I noticed the rocker arm on the right side head exhaust was tight when adjusting the axial gap. Everything is loose from the rebuild and nothing is set yet. The other 3 rockers were all "loose" compared to the this one. I popped off the retainer at the bottom and the screws at the top to pull the rocker off and have a look at the rocker arm shaft and it's stuck in the head some how. I was able to pull the intake rocker and shaft out no problem on the same right side head. When I put a punch into the oil hole at the bottom of the stuck rocker shaft to rotate it, it only travels maybe 30 deg and binds. The intake rocker shaft would travel freely side to side as far as I could turn it.

This stuck rocker arm shaft is the same location as the bent exhaust valves from the repair stated above. I'm disappointed the guy who put this together thought it was ok, it's clearly not. I understand the same forces that could bend the valves may have affected this shaft and I'm fine with ordering a new one to replace it. But, how do I remove it without damaging the head, valves, cam push rod, etc.? I did some "mild" beating on it trying to get it free.

RH Head Rocker.jpg
 
I don’t know all of the details of the valve replacement but my first thought would be to take it back to the outfit that did your valve job. It seems that they would have encountered it while doing your valves. Hopefully, they weren’t the cause of it. Good luck with your project. I ride the wheels off of my RS.
 
How to remove a stuck rocker arm shaft and what got it stuck anyway?

Absolutely no helpful suggestions from here so I thought I'd at least share my experience. Since I couldn't pull the shaft out and and remove the rocker arm from the head I cut it in half with a cutoff wheel. After that it came right out of the head and the top half of the shaft slid out of the top half of the rocker. The bottom halves were seized. I punched the shaft out with a socket in the vice and found the culprit. Not sure when/how that occurred, if it was a result of the over-revving incident that bent the exhaust valves? Either way, E-bay to the rescue with a used rocker and shaft.
 

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Re-Psycle BMW can be a valuable resource for those with older BMW bikes (airhead and up) needing parts.

I was fortunate in living fairly near Re-Psycle BMW for a number of years. They always had the parts that I needed in stock and good condition used stuff was half, or less, that of new.

https://re-psycle.com/
 
Interesting. Thanks for the pictures!

Is there supposed to be an oiling hole where the shaft is damaged?
I wonder if the rocker stuck and that’s what caused the bent valves.
 
Interesting. Thanks for the pictures!

Is there supposed to be an oiling hole where the shaft is damaged?
I wonder if the rocker stuck and that’s what caused the bent valves.

If the rocker arm stuck tighter than the valve spring could overcome, and if this is an "interference" design where the piston and valves occupy the same space at different times, then yes!
 
The picture of the cut rocker on a blue rag shows what appears to be rotational score lines near the end of the shaft. Is the shaft is supposed to rotate in the aluminum mounting block? Is there any appreciable wear there?

I’m just wondering where the metal that may have blocked the shaft oiling hole came from ...
 
The picture of the cut rocker on a blue rag shows what appears to be rotational score lines near the end of the shaft. Is the shaft is supposed to rotate in the aluminum mounting block? Is there any appreciable wear there?

I’m just wondering where the metal that may have blocked the shaft oiling hole came from ...

The shaft is supposed to be fixed.
 
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