Shims won't budge

[Guest]

Just now I attempted to start a valve adjustment on a 78 gs1000C engine, following BassCliff's guide. I checked the process twice. The bike has been off the road but was started regularly by the po when stored.

The clearances are too tight to get any feeler gauge in. The thinnest I have .0015. The shims are seated very tight and won't budge when I try to remove them. I have the OEM Suzuki tool for depressing the valves. I stopped there, pending advice from the the wise gurus here.

What does this mean, and what do I do now?

[Ghostgs1]

Are you using a pick in the slot of the bucket to loosen the shim? Oil film will hold them in pretty tightly until you break that suction. I don't see how the cam could be keeping the shim from being removed. Is it possible to get to that much seat wear? Ray

[cowboyup3371]

Where are you at Mac? Maybe one of us is close by and can lend a hand.

[MAC10]

Thanks everyone for the instantaneous replies!

I went throught the valves again, and the shims all turn when the pressure is relieved with the valve compressor tool. I tapped them very gently using a wooden drift. I think if I can break the oil film I can get them out.

Ghostgs1- The slot in the bucket I presume is on the bucket edge-is it possible to rotate the bucket until it is accessible? Nothing visible as they sit now.

Looking at a parts fiche, it looks like the buckets just sit there-nothing to prevent them rotating like the shims do, with a convenient notch no doubt with this problem in mind. I will try feeling for the notch with my old dental pick.

I am in the middle of BC- nowhere for several hours travelling. I am always amazed at how helpful folks are here! Willing to travel to help out a fellow GSR member.

[surviverguy]

If the engine hasn't run in a while (1 year or more) they can be difficult. I got the shims out of my non-running bike this morning. One of them was difficult as the shim and lifter would not rotate. I couldn't get to the slot. If the lifters and shims rotate it'll be easy. Rotate the lifter to access the slot on the side. Use a sharp small pick to get the shim loose and grab with a pair of tweezers.
If the lifter and or shim won't rotate- use some penentrating oil. I ended up carefuly striking that stuck shim with a punch using a hammer after soaking a while with pb blaster. If you use a punch- be careful of the lifter and the cam. That stuck shim had a touch of rust underneath holding it to the lifter. One strike from the punch broke it loose and then out she came.
Generaly no hammer or punch is required.

[derwood]

they are just a little sticky sometimes, they will come out, the buckets turn, (before you depress them)
you definitely don't have to remove the cams

[surviverguy]

I didn't have a tool for depressing the lifters. I used a plastic wire tie folded in half (doubled thickness). I rotated the engine until the valve was fully depressed (cam lobe pointing down). Then I stuck the doubled plastic wire tie in the sparkplug hole and under the valve. Then rotated the engine till the lobe was up. The wiretie held the vlave down giving lots of clearance. There is an advantage to this method when clearances are very tight because it enables the lifter to be rotated whereas with the valve depressor in use the lifter won't turn.

[surviverguy]

http://members.dslextreme.com/users/...ol_zip_tie.pdf

[MAC10]

Thanks everyone. I have been able to rotate number one so the slot is toward engine center, and I got that one out. I will be patient, and keep gently at it.

I will keep all the tips in my shop manual. They will be handy.

[1_v8_merc]

When you press the shim back in the bucket, make sure it's good and snug.
(don't go nuts over-oiling it or anything)
The reason I say this? Because I actually had a shim get jammed once. I went to turn the motor by hand, the cam lobe "caught" on the tip of the shim, causing it to fly up against the aluminum wall, and got jammed. I carefully pried and turned the motor in reverse, and it eventually came out!
(I put too much oil on the new shim, before placing it back on the bucket. So I guess the shim was actually floating in the bucket, instead of actually being fully seated! The funny thing is, I pressed it down just like all the others, but I guess some oil crawled under it, causing it to barely rise up, and I didn't notice.)

I got a nice imprint in the side of my valve case too, lol.
I wouldn't worry about it though, it's probably just a freak occurrence.

[Ghostgs1]

Also remember to only work on 1 valve at a time, removing more than one shim can lead to bucket and cam damage. Good luck. Ray

[MAC10]

I finished the valve adjustment today, and needed no shims I didn't already have in stock. All the valves were tight, indicating no adjustment for a long time. 3 of the exhaust shims were a funny light blue color, different than the deep blue most used shims are. Is this significant?

I at first thought it was an indication of high temperature, which makes sense on too tight exhaust shims. I will be doing a compression test next week, when I hope to have this one running, to check for signs of bad valves.

The job was made easier with my very long, skinny and flexible needle nose pliers, which worked better than my tweezers for pulling shims, and my metric vernier caliper for checking the specs of used shims , some of which were put in with the numbers toward the cams.

The engine is otherwise looking not too bad, as far as I can tell without it running-that is the only test that means something.

[surviverguy]

congrats on getting your valves adjusted. I started a day before you and still haven't finished....waiting on Z1 shim delivery...I hope your compression numbers are good. A valve job would be a pita.

[1_v8_merc]

My local shop ordered me shims at $4 a piece.
Guess we'll see how long they last in the 650.

[7981GS]

My local shop ordered me shims at $4 a piece.
Guess we'll see how long they last in the 650.

Make certain that they didn't order the Kawasaki or Yamaha 29.00 mm shims for that price.

Eric