Valve adjustment.. where to start?

[Guest]

I decided that on top of rebuilding the carb and properly cleaning it, I will adjust the valves as its no mystery there is backfiring out the intake and severe carbon buildup. I've looked on some threads and haven't been able to find my questions answered, so here goes:

1. What size shims do I need? Not thickness by diameter?
2. What is this valve depressor tool do?
3. What gaskets do I need and can any be replaced with liquid gasket?
4. Is there anything I'm missing?

[Steve]

I am just going to copy your questions, then answer them.

1. What size shims do I need? Not thickness by diameter?
The thickness you won't know until you open up the top end and measure your clearances, then remove the shims (ONE AT A TIME), inspect the sizes and do some calculation. The diameter is easy, they are 29.5mm. If you want to minimize some expense, look into the GSR Shim Club.

2. What is this valve depressor tool do?
The valve depressor will push the bucket that holds the shim down, away from the cam, so you can remove the shim. Many of us have found a hard time trying to use the official tool and use a zip-tie, instead.

3. What gaskets do I need and can any be replaced with liquid gasket?
Usually, the only gaskets you will need will be the valve cover and the breather cover. I would NOT recommend using any liquid gasket, or even any type of sealer to 'help' the stock gasket. Use the gaskets dry or lightly-coated with oil, which increases the possibility of using them a second time.

4. Is there anything I'm missing?
Just one thing. WHAT BIKE DO YOU HAVE???
Not all GSes use shims. Depending on the bike you have, all of this information might be useless.

If you DO have a bike that uses shims, I will invite you to take advantage of the offer in my signature.

.

[gsrick]

I decided that on top of rebuilding the carb and properly cleaning it, I will adjust the valves as its no mystery there is backfiring out the intake and severe carbon buildup. I've looked on some threads and haven't been able to find my questions answered, so here goes:

1. What size shims do I need? Not thickness by diameter?
2. What is this valve depressor tool do?
3. What gaskets do I need and can any be replaced with liquid gasket?
4. Is there anything I'm missing?

1. You'll be able to answer that when you take out any tight shims. You may not need any if you can move some loose ones around to fix you tight ones, but that rarely happens.
2. The tool compresses the tappet or bucket down at the edge so you can remove the shim. This is done with a small flat blade screw driver, a dental pick or tweezers. The letter can also help place the shims back in. There is a zip tie method someone else can explain, since I use my tool.
3. I recommend replacing the breather and valve cover gasket and half moons if they look distorted. You can use some black RTV gasket to help seal these where they come in contact with the VC gasket.
4. Some people recommend putting the half moons in backwards with the lip on the inside as some people have had them blow out. I have never had this problem, but that is more than likely because I use RTV on them. Also check and recheck you measurements and rotate the engine a couple of times to make sure the shims are properly seated. when check in the measurements and there will be disagreement from some here, but you can check four valve clearances at a time. When #1 cylinder is at TDC, you can check the intake and exhaust valves on that cylinder and the lobes that are pointing away from the valve on # 2 and #3, one of those will be an intake and the other an exhaust. Rotate the engine 180 and bring #4 to TDC. Check IN and EX on #4 and the ones at #2 and #3 that you didn't already check.

You will need some good metric feeler gauges and a micrometer. A digital vernier caliper will work if that is all you have, but I prefer a micrometer for checking the actual shim thickness. Don't trust the numbers written on them as they ride under the lobe and get thinner from wear and in some cases, as is with new replacement shims, they come in size increments of .05 and the factory ones come in .01, but they round up, so you may need to play around for the best clearance possible across the head. Keep them organized as to not mix them up. Also there is a shim club here that may help you get the shims you need.

I almost forgot, since you have the valve cover off, you should check the torque on the head bolts.

[salty_monk]

I usually start by putting the bike on the centrestand, after that I remove the fuel tank...

[fastbysuzuki]

Whatever you do, do not attempt to rotate the engine when there is no valve shim in the buckets.

[azr]

I usually start by putting the bike on the centrestand, after that I remove the fuel tank...

ha,ha,ha,ha,ha,ha,ha,ha,ha,ha,ha,ha,ha,ha,ha...... ........

[gsrick]

Whatever you do, do not attempt to rotate the engine when there is no valve shim in the buckets.

Not many people think of that and double check that the shim is fully seated when you put them back in.

[Jrgunn5150]

Whatever you do, do not attempt to rotate the engine when there is no valve shim in the buckets.

I probably would have done that for some reason had you not posted this.