Broken Shim. opinions needed.

[Grimly]

I'd be inclined to blame the shims for being sub-standard. Never had an OEM one fail like that, but they can in the right (wrong) circumstances, if not seated properly and get partially spat out. Assuming you had seated them properly and the cam profile is ok, and the right springs were used (as you say), I don't think operator error is to blame here. Too many reports of bad shims in the last couple of years, and as mentioned above more than one dealer is aware of the problem and has taken steps to rectify it once aware. Some sweatshop knocking them out in a far-flung corner, paying little attention to quality control.

[Sand_fiend]

I was doing some final tuning when this happened. i had ridden it around my neighborhood off and on for about two weeks getting it tuned in. it had about 6 or 7 miles on it.
I had the valve cover off last week doing a valve clearance check again so i know they were all the way seated..

I talked to megacycle this morning. it's going to a around $70 to fix the lob.
I guess i got what i payed for cheeping out on not wanting to pay for OEM shim's

[Ghostgs1]

If they were at .006" or .15mm that may be a big part of the problem. That is quite a lot of clearance, much more than the spec. for the cam.

[Chuck78]

I fully agree that more than .004" of lash is too much, & with a lumpy cam, you will have a harder impacting motion of the lobe to the shim/bucket.

On the other hand, I have seen many posts of people breaking shims in recent years, sometimes really screwing up their engines. Absolutely none of these that I have seen were OEM shims, always the square edged K&L's with the ink stamps just like the ones this poster broke.

Basically I agree with Nessism&Z1 completely, but additionally would not recommend anyone using this type of aftermarket shim for aftermarket cams or for a bike that sees a lot of heavy throttle twisting action in the upper rpm powerband.

[Sand_fiend]

Darn.... to keep it clean.. I just found that the Guide is cracked in three places on this bent valve..