Valve shim hitting bucket?

[Bartman]

Hello all,
I have been working on a 78 Standard for most of last year. Once it was running it seemed to get richer as it warmed up. I have gone through the carbs several times and finally decided to pull the valve cover and see how the clearances were. All were either tight or very tight.
I know that there has been a lot of advice on valve shim changing but I would like to share my slight modifications and also a question for the group.
The shim tool has several forums written on how it doesn’t align up with the bolt holes. I agree and instead of widening out the holes I used vise grip pliers to hold the tool. I must say that this allows for a quick hold down without trying to get the bolt to line up. I still had a hard time getting the shims out of some buckets. The shims would become loose but there didn’t seem to be enough head / wiggle room. I figured that the tool wasn’t holding the bucket down far enough. So, I ground the bottom of the tool that seats against the head. This seemed to push the bucket down just a little bit further and the shims then came out with a problem. I am going to try and attach pictures, (my first time so hopefully you can see my pictures.)
http://s1339.beta.photobucket.com/us...52562957547186
Now for my issue/question. I have read a lot of advise you guys have written and I haven’t seen anything about not turning the motor over without shims in the buckets. I read that you measure gap, remove shim and replace with the correct size. Most forums say to take the shims to the local bike shops and that they will swap them out. Based on this I measured gaps and then took out all of the shims. When most of the shims were out and I was rotating the motor I heard a “Snap”. I know that didn’t sound right but didn’t see anything at that time. I did not bump the tool with the cam! The motor would rotate with no apparent issue. I was able to reuse four of the shims in other spots and the local shop swapped out 2 more. I had to order 2 on line.
As I was putting shims back into the buckets I noticed that the cams had grinding on the edges and shards of material on top of the buckets. I now think that the buckets rode up higher without the shims in and the cams bumped the edges.
I blew out the buckets and replaced the corrected shims in and am buttoning it all up but haven’t cranked it yet. Do you think that the buckets are damaged too much? Has anyone else done this before?
Thanks, Bartman

[bikerphil]

Rotating the cams with the shims out is a no no, hopefully you checked closely for damage on the edges of the buckets and on the cams.

[Bartman]

I looked but didn't see anything. The shims when in with no binding.....hopefully the bucket won't scratch up anything

[Bartman]

The tech reports need to spell out no shim/no turn!

[bikerphil]

Most forums say to take the shims to the local bike shops and that they will swap them out. Based on this I measured gaps and then took out all of the shims.

If you are going to do this, you should remove the cams. Then all the shims can be removed at once. You are correct, the FSM does not say not to do what you did. It just tells you the correct procedure which is to replace the pad with the new size then move on to the next. Hopefully everything is ok on your motor, I would rotate it a few times by hand before cranking with the starter. Good luck!

[scoot]

Been there, done that too

I did the same thing about 2,000 miles ago. The cam lobes fractured off just as in your picture, the pieces stayed on the bucket. With the shim removed, the bucket lip will contact the outside edges of the high point of the cam lobe. Seems the bucket stays strong and the cam fractures. I buffed it like a bit of a chamfered edge with 600 grit paper as I felt the fractured edge was not smooth enough at the cam face, enabling the cam to scratch the bucket and/ or the shim creating more filings in the oil. Before installing the shim I sprayed the bucket clear with carb cleaner with a clean rag to catch the particles, then aapplied clean oil to the bucket and the bottom of the shim ,then installed the shim.


scoot

[ViperRon]

I am not trying to give you extra work to do but its hard to say if you got all the material looking and cleaning from the top. The problem is that a shaving could fall between the bucket and head and even though it does not hang at the moment it could hang latter. What could happen is the bucket hangs leaving the valve open till the piston slaps it. I suggest that the cams be pulled build a chart of what shim came from what cylinder and the buckets are pulled and kept in order so the correct bucket goes back in the original spot and then clean out with a magnet, air, spray what ever to ensure all is cleared.

You may not have anything in it but as I said you have already had this problem and I am letting you know this is a possibilty. Its up to you as Clint Eastwood would say (Well do you feel lucky!!!!!)

[Bartman]

I did as Scoot did, I blew out with carb cleaner, then with a basket ball needle from my air tank. Then oil and shim back into bucket. I plan on changing oil in motor very soon in case cleaner or particals went down into the motor.
I don't want to be lazy but I think that I am going to go for it and see how she runs.
I didn't really want to pull the cam out of the top end with the motor in the frame. I am still learning.....
I really want others that only have one bike to know that they can't just swap a shim from one spot to another using the tool. Unless you have a hand full of loose shims ready for this task. Unless you pull the cam!

[GLoweVA]

I really want others that only have one bike to know that they can't just swap a shim from one spot to another using the tool. Unless you have a hand full of loose shims ready for this task. Unless you pull the cam!

The key to that is knowing what shims you have in there to start with.
Once that is known and then you check the clearances, then you can figure what shims you'll need and you'll already know what shims you already have installed to 'reuse'. Then it's just a matter of swapping those around, or going and getting one or two 'new' ones.

Unfortunately, the first step is to find out what shims are in there. I found that it was easier to pull both cams in order to pull all 8 of the shims out to write down what sizes they were. This can be done with the tool, one shim at a time. As far as which way would be less time, I couldn't guess. They may be about the same.
Plus, some of my shims were really hard to get out of the bucket too. on a few, I ended up pulling the whole bucket out of the head to get better access to the shim.

Just my experiences. (and I don't have a tool, so I didn't really have a choice.)