Valve shim question

[Guest]

78 1000. I did the shims last December and then 4-5 weeks ago I checked them again because I was having a few issues with one of the cylinders. I was surprised that some of the shims needed swapping, a bit tight if I remember correctly. The bike had a strange tick noise in the last week so I pulled the valve cover off to check things and 4 of them were well on the loose side of 0.08. Anyone have thoughts on why this would be? I should be getting several thousand KMs out of a shim job.

[7981GS]

I try to get them between .05 and .08.
So what is wrong with it?

Eric

[Guest]

There was an odd ticking noise coming from the #2 area. Thought timing chain but it was rebuilt last year and checked out fine when I looked at things tonight. How do you get your shims in that narrow band? the shims are .05

[7981GS]

When TimTom left here the other day, we even used some of the oddball shims to get his bike damn near perfect. (2.57 & 2.62)
Both of the outer cylinders had the same clearances and so did the center two. (within .01 of each other)

Eric

[salty_monk]

The "X" shims are plus 0.02 as Eric says. I used the Shim club, opened it up, measured & got Ghost GS to grind them all to the exact right sizes to put everything on max tolerance last time I did it.

I am not expecting to do it again for 15k miles....

Usually I would expect a valve to close up 0.01 about every 4k miles. You have to get a feel for your bike.

The fact that they went tight & then loose suggests to me that the middle "tight" reading was perhaps a false reading. Did you do it the Suzuki way or the Clymer way? After replacing a shim I try to rotate the engine a couple of revolutions to settle it in before I measure.

[Steve]

Another possibility is that, during the first reading, there might have been a bit of crud under the edge of the valve, holding it open just a bit. Some time before the second reading (while the engine was running for how many miles?), the crud left, leaving just a bit more clearance.



How long have you had the bike? How many valve adjustments have you made on it? Have you seen any trends in valve clearance?
There is some guy here that offers a spreadsheet that helps keep track of that kind of stuff.
He has information about it in his signature.

.

[Guest]

Another possibility is that, during the first reading, there might have been a bit of crud under the edge of the valve, holding it open just a bit. Some time before the second reading (while the engine was running for how many miles?), the crud left, leaving just a bit more clearance.



How long have you had the bike? How many valve adjustments have you made on it? Have you seen any trends in valve clearance?
There is some guy here that offers a spreadsheet that helps keep track of that kind of stuff.
He has information about it in his signature.

.

Your spread sheet I remember getting that 5 years ago with my first GS, I had such high hopes for myself and keeping organized and all. It would be such a help with situations like these but alas I live my wrenching life constantly a little (or maybe it's a lot) scattered. I've had this bike rebuilt and on the road for over two years now. I took it to last years Rally at Bruce's so it's had some serious mileage put on her. Last December was the second shim job I had done since putting her back on the road, everything seemed normal for the amount of KM's I had put on last season. As far as 'crud' being in there. I never opened the engine up during the rebuild but a month or so ago on BigT's recommendation I used some oil additive to help loosen up some possibly sticking oil flow rings, and it worked like a hot dang, maybe that had an impact? When I'm doing valves I usually do it the Cliff way and always rotate the engine several times and recheck every shim before I button things up again. The one BIG difference with my technique now is I'm using the valve shim tool instead of the twist tie method. Way faster. One question, after doing a shim job is it normal to have the shims seat a 'bit' more once the engine has been run a bit?

[Guest]

The bike had a strange tick noise in the last week so I pulled the valve cover off to check things and 4 of them were well on the loose side of 0.08.

Better looser than tighter. If you can get the other 4 that way you should be able to go awhile before the next check!

[7981GS]

The one BIG difference with my technique now is I'm using the valve shim tool instead of the twist tie method. Way faster. One question, after doing a shim job is it normal to have the shims seat a 'bit' more once the engine has been run a bit?

As Tim Tom will tell you, I always rotate the engine at least 3 times after changing all of the shims and then check them again.
Hopefully, 3 times is enough to get them all to seat and usually at least one seems to need another shim to be even closer to your goal.

Eric

[Steve]

Your spread sheet I remember getting that 5 years ago with my first GS,

Yep, in a couple weeks, it will be 5 years since I sent out the first copies, but I don't see your name on the list until January, 2011.

One question, after doing a shim job is it normal to have the shims seat a 'bit' more once the engine has been run a bit?

When I am done changing shims, I will hit the starter button and hold it for about 5 seconds so the cams will beat the shims into submission several times, then re-check clearances before putting the cover back on.

.

[Guest]

Yep, in a couple weeks, it will be 5 years since I sent out the first copies, but I don't see your name on the list until January, 2011.



When I am done changing shims, I will hit the starter button and hold it for about 5 seconds so the cams will beat the shims into submission several times, then re-check clearances before putting the cover back on.

.

That's weird, I'm sure it was a few years before 2011. I should really find that email again and put it too good use. If you hit the starter button doesn't that send oil spitting everywhere?

[Steve]

That's weird, I'm sure it was a few years before 2011.

If you don't find it, let me know, I'll send you another one.

If you hit the starter button doesn't that send oil spitting everywhere?

It oozes out from under the cam bearing caps, but there is nothing "spitting" or even "squirting".
And the cams are not turning fast enough to splash in the pools that are around the buckets.

.

[Guest]

Right you are Steve, appreciated that little tid bit, really made me feel the shims were securely seated and I could trust the measurement afterwards. Rechecked the shims this morning and got them all in between 0.045 as the tightest and 0.08 as the widest. Most are around 0.05 and 0.06. That's got to be the most time I've spent playing with the spacing for sure, lol. That's what I call job done. Going to synch her again and hopefully that little tick is gone and if not then I'll just chalk it up to another reliable noise of a 34 yr old bike. I'm pretty sure all this work is due to the fact we're leaving on a 2 week trip on Saturday and I've the the pre trip jitters. I think after this I had better lock the shed with all the tools!

[old_skool]

Right you are Steve, appreciated that little tid bit, really made me feel the shims were securely seated and I could trust the measurement afterwards. Rechecked the shims this morning and got them all in between 0.045 as the tightest and 0.08 as the widest. Most are around 0.05 and 0.06. That's got to be the most time I've spent playing with the spacing for sure, lol. That's what I call job done. Going to synch her again and hopefully that little tick is gone and if not then I'll just chalk it up to another reliable noise of a 34 yr old bike. I'm pretty sure all this work is due to the fact we're leaving on a 2 week trip on Saturday and I've the the pre trip jitters. I think after this I had better lock the shed with all the tools!

If it quits ticking, then I'd be worried, every UJM I've owned, ticking is a sign of normal valve clearance, if it's something your not used to hearing thats different, but I wouldn't expect it to go away alltogether.

[Steve]

..., every UJM I've owned, ticking is a sign of normal valve clearance, ...

True, some noise is normal, but how the heck are you going to hear clearances in the range of our engines?

Every other engine I have worked on had clearances that were much larger than what we have on our GS engines.

Of course, those are the COLD clearances, no telling what happens to them when they get HOT.

.