Valve Shim Question, 1979 GS1000

[Meweeble]

For nothing more than consistency and the inherent nature of the specs of the bike, I choose to utilize and quote metric. But I still have a question.... If my tolerances are really tight like that, around .00 what will the results be a low rpm? I seem to have a little blow back through the carbs and vacuum is inconsistent (hard to tune the carbs). Will setting the valves help? Oh and I did order a set of shims 2 sizes down.

[Nessism]

It's hard to say if setting the valves will solve your bikes running problems but it's not going to hurt. And if you don't set the valves, I guarantee the valves will burn up and damage the head too.

[Guy]

I'm not American I'm Canadian and we use the metric system. so it's .03mm

I wasn't assuming you were american or otherwise. I was responding initially to Basscliff's comment.

For nothing more than consistency and the inherent nature of the specs of the bike, I choose to utilize and quote metric. But I still have a question.... If my tolerances are really tight like that, around .00 what will the results be a low rpm? I seem to have a little blow back through the carbs and vacuum is inconsistent (hard to tune the carbs). Will setting the valves help? Oh and I did order a set of shims 2 sizes down.

Of course, it makes sense to utilize and quote metric, and that was my original point, but it appears to have gone over the heads of some......

But to your question, yes. You won't be able to sync your carbs properly with the clearances so tight and you'll end up burning up your exhaust valves and possibly the seats too. Loose and a little noisy is preferable to tight, and you won't need to worry about it for a while.

[Meweeble]

I wasn't assuming you were american or otherwise. I was responding initially to Basscliff's comment.



Of course, it makes sense to utilize and quote metric, and that was my original point, but it appears to have gone over the heads of some......

But to your question, yes. You won't be able to sync your carbs properly with the clearances so tight and you'll end up burning up your exhaust valves and possibly the seats too. Loose and a little noisy is preferable to tight, and you won't need to worry about it for a while.

Great.... because I've done everything suggest on the site and by members and this is all I have left to do. We'll see in a couple of days when I get the shims.

[Swarley]

Valve shim and valve adjustment

I bought my 79 GS1000 last year and just had the valve shims checked by a Suzuki shop to find out what condition she is in. They told me they are in spec, just barely, and after a couple thousand more miles I'm going to need the valves adjusted or I'm going to burn up valves. They said they have to pull out the cams to do this, I was under the impression that this was all done by the shims. Why would they have to pull the cams? Thanks for the info.

Kevin

[7981GS]

I bought my 79 GS1000 last year and just had the valve shims checked by a Suzuki shop to find out what condition she is in. They told me they are in spec, just barely, and after a couple thousand more miles I'm going to need the valves adjusted or I'm going to burn up valves. They said they have to pull out the cams to do this, I was under the impression that this was all done by the shims. Why would they have to pull the cams? Thanks for the info.

Kevin

Don't ever go there again. They obviously don't know what they are doing!
Buy the shim tool and do it yourself. Z1 enterprises sells them.

Daniel

[FLHGSRay]

Don't ever go there again. They obviously don't know what they are doing!
Buy the shim tool and do it yourself. Z1 enterprises sells them.

Daniel

What he said. Buy the tool and do it yourself. Chances are you will only have to buy 1 or 2 shims. That's why you record the shims that are in there, so you know you can move 1E to 4I, as an example. When I recently did my '79 GS1000, I only needed 1 shim, and the Suzuki dealer exchanged it. No charge. And I used STANDARD feeler gauges.

[Swarley]

Thanks, I was starting to wonder that. So as long as the clearance hasn't gotten too small the valves haven't burned up and wore into the head, I just need to put different shims in to get the clearance more in range? Or when do I have to start wondering what condition the valves are in? Thanks again.

Kevin

[FLHGSRay]

So as long as the clearance hasn't gotten too small the valves haven't burned up and wore into the head, I just need to put different shims in to get the clearance more in range?

Exactly, Your first concern is that you actually HAVE clearance. Then, how much? Most feeler guages only go down to .0015". I had one valve that the .0015" wouldn't fit in, so I had to get some .001" shim stock to check it. When that did fit, (it was tight), I knew I at least had clearance and the valve wasn't being held open. I then pulled the shim, a 280, and exchanged it at the dealer for a 275. That brought it right into spec. And now, since I've recorded the shims and clearances, I have an idea of what I may need next time. Some time soon, I'll pick up a few 270s and 275s. And you DO NOT have to pull the cams to do this. Simply pull the top cover, rotate the cam until the lobe is in the proper position for each valve, measure/record the clearance, spin the bucket until you see the notch, push down the bucket with the tool, remove/record/replace the shim, then release the tool.

[Super]

I just did the valve shims on my 1983 GR650...recently purchased...and all 4 were too tight to fit the .03mm feeler gauge. The bike showed 12K mileage.

The existing shims were: 2.75, 2.80, 2.75 and 2.75. The replacements shims needed to set them right ended up being 2.65, 2.75, 2.70 and 2.70.

So yes, all 4 could be too tight. Hopefully your new shims will do the job. I, sadly, have yet to crank my bike up since the shim change. Waiting to put the rebuilt carbs back on along with the new chain and both new sprockets before I do because then...I can take her out!!

Good luck with yours.

[7981GS]

Insert shameless plug here: http://www.thegsresources.com/_forum...d.php?t=189085




Daniel

[Swarley]

OK, so I pulled the cover and checked the clearance I have. My feeler gauge only goes down to .002 in. and that won't go in. It feels like it might want to but it won't. I have the tool on the way so I can't pull the shims to see what I have in now. Do I need to find a smaller gauge to see IF I have any clearance? Thanks

[matt1100]

There may be a more scientific method but I shot from the hip the first time. Do not think one shim stayed where I found it. Some moved around, some recieved new ones, some pushed spec until I got the right ones. Lil grease on the gasket and it comes right back off and can be reused. Mr. Steve has a cool spreadsheet to help keep track of the process, all you have to do is ask for it. Good Luck, you'll be suprised how much that motor wakes up when they are right.

[1948man]

It's a metric bike but the original Japanese service manual gives specs in mm and inches. I bought a metric set of feelers but only because the SAE set didn't go below .04 mm (approx). A lot of feeler gauge sets here are marked in thousandths of and inch and nearest metric approximation.

[Swarley]

So I got my shims in and was in the process of putting her back together when I realized the cylinfer head cover bolts are 2 different lengths. Can anybody help me figure out where the longer ones go, I see where a couple go but the other places seem to bottom out a little before the cover.