Hey folks!

So I'm having some difficulties finishing my valve shim adjustment. I have a whole long narrative which I can lay out, but I'll spare you all that for a moment and just ask a few questions for starters.

1) Are there any theoretical consequences to cranking the engine over (with a wrench on the crank, of course) while some of the shims are out of the tappets?

2) My RT exhaust tappet won't rotate freely anymore, and comes up higher than normal without a shim and when the cams are aligned correctly for adjusting that particular valve. Any thoughts?

3) And finally, any reason why I can't rotate the crank even if all shims are seated correctly and the bike is in neutral, etc.? It cranks in reverse (only went an inch or so bc I'm not sure what can happen if I go too far backwards - just mentioning it so you know it's free up until a certain point).

Like I said, I can lay out the full story if necessary, but any thoughts on these questions would be greatly appreciated.

Thanks!

Do you have the plugs out?
Try turning it over by putting it in 6th gear and pushing the bike or turning the back wheel by hand, should turn over easily without the plugs.

Sorry, forgot to specify - plugs are out and it was turning over at one point before.

Possibly your shims are too thick and hence the cams have no chance of opening the valves?
What does the top end look like and what is it doing when you try to manually turn the motor? (You should only go clockwise).
Could something have fallen down into the motor and is locking up the cam chain?

If memory serves me correct I wouldnt crank it over with the shims out the buckets, they can damage the cam lobe.

A little more background. The shim was actually .05mm thinner than the previous one (which still had .04mm of clearance, so it wasn't a problem before. Cam lobes look to be okay but one may be slightly scuffed. And I had a rag in the galley and I'm not missing shims/tools so I don't believe anything could've fallen down into the motor. When I put the new shim in, it was hard to turn but eventually went around one full cycle before locking up again at the same spot (the position for adjusting RT exhaust and LT and RT intakes). Just feels like it's at a hard stop.

So now the rest of the story. Besides previously turning it one revolution without all the shims in, I initially had a hard time getting the shim out. The official valve shim tool was giving me trouble (I now realize it doesn't orient perfectly perpendicular to the camshaft when you put it in, but rather you have to angle it in slight to get it to actually stay on and depress the tappet as you rotate it down).

So I decided to try the "screwdriver method." This resulted in me scuffiing the inside of the block just to the left edge of the RT exhaust tappet. Basically scraped some paint off and exposed some aluminum from the block, producing a few shavings (which do not seem large/strong enough to grind anything to a halt). The tappet still rotated freely in there so I cleaned it out as best as possible and got the new shim in.

Now, I'm stuck on that position, the shim has zero clearance (even though thinner than previous (2-60 vs 2-65) and the tappet won't rotate. What's more, the tappet seems a little higher up, closer to the cam than it did before.

I think I maybe upset something below the tappet (the piece in between it and the top spring retainer perhaps?). Or maybe something at the valve/piston? I have no idea.

Hope that's clear enough and looking forward to the replies. Thanks guys.

depending on miles  and how hard the service was.   could be a number of things.   your saying the shim bucket sits higher  then normal, and is tight even with a thinner shim,  try a thinner shim then that.  its possible a burr might be giving the bucket a headache but i can think of things far worse to be causing your problem.  the part that worries me is not being able to turn the crank very far.   hope you didnt bend/break a valve or have a keeper give up.

Quote from: slipperymongoose on December 07, 2013, 05:20:11 PM
If memory serves me correct I wouldnt crank it over with the shims out the buckets, they can damage the cam lobe.

That will scratch up the cam lobe a bit ... but I rode one with a nice crow's foot look scratch in mine for 40K miles ... It takes oil and holds oil and self restricts its own wear ...

Cool.
Buddha.

Are you sure you haven't broken a valve off the stem? That could explain the bucket sitting too high and the inability to crank over.

Broken valve would cause lockup of crank at position you describe with right piston coming up to top.  Have you looked into the plug hole to see if you can see it, I broke my right exhaust valve one freezing cold morning when a too tight bucket held it open and could see it thru the plug hole.  You may have dislodged chips that held the bucket down long enough to go bang, broken valve would release bucket upwards..

Metal shavings locking the bucket in the up position?
You mentioned metal shavings and that the bucket now does not turn freely.

As always, thanks for the thoughtful replies, guys.

So I had a look in the right plug hole and I saw what looks like the valve, dropped all the way down, just sitting on the piston.  I could see the valve stem and everything. That means the valve or something in between it and the tappet up top broke and the valve just dropped down, right?

Which means ultimately the head has to come off?

My guess in this case and it's only a guess is that one of those chips/shavings got wedged in between the tappet and it's bore and held the valve open just long enough to cause an internal collision. At least you know what needs to be done now; off with the head!

By the way, there is nothing between the valve and the tappet unless a keeper somehow got loose in there.

Yep, thanks Jack.

It'll be a couple days before I can pull the head. I'll be watching videos and reading the manual in the meantime. I'm definitely in over my head now (if I wasn't already!). I don't imagine the fix will be really simple and I certainly don't have anything beyond the standard hand tools. From reading other posts, it seems the thing to do would be to just get the head off and take it to a mechanic...

Quote from: younastytwin on December 08, 2013, 11:31:00 AM
Yep, thanks Jack.

It'll be a couple days before I can pull the head. I'll be watching videos and reading the manual in the meantime. I'm definitely in over my head now (if I wasn't already!). I don't imagine the fix will be really simple and I certainly don't have anything beyond the standard hand tools. From reading other posts, it seems the thing to do would be to just get the head off and take it to a mechanic...

What is left may be salvageable. Just leave everything as-is and take it to a machine shop. Trust me.

(from a guy who is way in over his head time and money-wise and wishes he had just taken the original head to a machine shop)

Pictures of inside of bucket (tappet) and top of valve/spring assembly:



And my broken exhaust valve: 



Actually it can be better to have a broken valve than a bent one if you have a tight bucket, the bucket can be very difficult to get out.  I was able to reach up thru the valve guide from inside of head to drive out the remaining piece of valve stem and the too tight bucket with a long punch and hammer.

Thanks again, Jack and company. I can see a lot of the stem through the plughole so either I broker mine higher up on the stem or something else came loose/broke. I'm going to pull the head tomorrow night so we'll see.

One last question - with 12k miles, is it likely that I'll be able to re-use the head gasket and O-rings, or is that asking for trouble?

If you re-use them, you're not asking for trouble. You are DEMANDING trouble.

I think if you have to ask if it is OK to re-use gaskets, you should be using new. Gaskets are cheap compared to having to take it all apart again because the re-used gasket didn't seal.