Broken Elephant Foot Valve Adjuster

There was some Ni, but it was very miniscule under .05%. Like I mentioned, we had a hard time getting good readings. The gun is set up for larger pieces of scrap so it may not have been able to get a really good read on it. I wanted to try and test the foot of the adjuster as well as the threaded shaft to see if there was a difference, but we could not get it focussed in that tight.
 
5twins said:
I've never used a torque wrench on the adjuster lock nuts, just made them what felt right (and tight enough) to me. You said that 20 ft/lb spec was very tight, tighter than you were making them without a torque wrench. Maybe it's too much for these aftermarket screws and that's why they're snapping off? Maybe it only applies to factory screws?
Click to expand...

I found the torque specs for Porche and it was also 20 ft lbs.
 
But the CB (or EMPI) aren't genuine factory parts, they're aftermarket. I did some research on the lock nut torque spec for the 650 over the years. The 1978 manual does spec 20 ft/lbs but as far as I can see, it's the only one. All the later models spec 19.5, and the earlier ones even less, 11 to 18. I don't see the point of making them 20. Next time I do a valve adjustment, I'm going to check my "hand tightened" nut to see if I can determine just what I'm using. I'm thinking 12 to 14 is probably all that's needed.
 
I checked a CB in a coned rocker arm and the thread length is perfect. A stock racker arm has 12mm of threads, my modified rocker arm has 9mm of threads and with a CB set approximately to operating position there is 9mm of thread engagement. So, with a Empi the thread engagement would then be about 5mm and with the OEM Porche units perhaps a bit more based on the picture in this thread.

http://www.xs650.com/threads/elephants-foot-valve-adjuster-comparison-porsche-vw-mikes.32559/

It that enough? Doesn't sound like it to me. What we need is a CB with better materials or tighten them less.

Sure miss the elephant foot adjusters, rode my bike today and the valve clatter is much louder.
 
I believe those are CB's. Same price and identical units. Probably just repackaged and given a new part number. You could call them and ask the name brand. I'd bet they are the same.
 
Those sure look like the CBs to me, but seem to have a better finish than mine. I'm smelling bait-and-switch.

Not having much luck looking up that unusual Fe-Ti-Mn-Cr-Mo alloy. If I ignore the Ti and Ni, then its like that 8620, close to 4140. Found a mention that sometimes a small amount of Ti helps to reduce the grain size. Tempering of the 8620 is a low 200°C. Not getting warm fuzzies from this, thinking some sort of chinese trash steel...
 
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Did a bunch of digging on torque specs for VW's, talked to CB performance, watched several videos on adjusting the valves on a VW paying close attention to how much oomph was put into tightening the lock nuts, checked torque specs for various grades of 8mm bolts and considered 5twins report on 650 torque specs and decided to get some new CB's and torque them to somewhere around 14 ft lbs. Based on the above and some experiments I did torqueing old CB's in spare rocker arms I am convinced they will be fine.

I think they just couldn't take getting near the 20 ft lb spec for my '78 XS.
 
What did CB Performance say? Did they feel 20 was too much? Did they have a torque suggestion? Even though I've had no trouble with the EMPI screws, I sure do like the looks of the CB ones better and would like to use them.
 
CB looked up torque specs for VW's, I think they said 16. I also asked if they had ever had reports of problems like this and the answer was no.

I ended up ordering another set, CB performance was out of stock so I found a set at Pierside Parts.
 
The ones I got last summer are the 1518's. Hopefully they are "improved".
 
Mine are p/n 1518.

http://www.xs650.com/media/cb-performance-1518-elephant-foot-adjusters-around-40-for-8.13697/

Look closely at the the "rolled" threads.

http://www.xs650.com/media/cb-elephants-foot-cup-is-hardened-disassembly-will-crack-it.21322/full
full
 
Found a page from the 74-76 manual that shows adjuster nut torque at 11-18 ft-lbs torque. Myself, I tend to go to the lighter side, say around 12 ft-lbs.
74-76-Torques.jpg
 
Well at 12 ft lbs I would have no concerns about this happening again. I wonder why Yamaha upped the spec to 20 for '78.

Anyway, the new 1518's came in and although they look the same as the 1411's new they are much smoother and I expect they will take much less time to bed in. Got 4 of them shortened and slotted and ready to go, I may put them in this weekend.

Went for a ride today riding double with temps around 90. It's amazing how much more tappet noise it makes with the stock adjusters!
 
I've been cogitating on another "blue sky" project.

A strategically placed, EDM hole, of about 0.010"-0.015" (0.3mm), in the rocker arm body, emanating from the rocker shaft oiling groove, aimed directly at the adjuster tip.

XS650-RockerSquirter01.jpg
XS650-RockerSquirter02.jpg
 
I remember XSJohn doing something like that but I think he ran oil lines externally.

Seem like it should help because that does seem to be a weak point in oiling.
 
TwoManyXS1Bs said:
I've been cogitating on another "blue sky" project.

A strategically placed, EDM hole, of about 0.010"-0.015" (0.3mm), in the rocker arm body, emanating from the rocker shaft oiling groove, aimed directly at the adjuster tip.

View attachment 99869 View attachment 99870
Click to expand...
Hello @TwoManyXS1Bs

I appreciate you this thread is from a few years back but I only stumbled across it last night and I have to say I’m really interested in the modification you suggest, I plan on using the Porsche valve adjustment screws so whilst the rocker arms are being modified to work in conjunction with these I thought “why not?”


Daniel.
 
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