Aw man why does it have to be so hard??

[JimmyR]

So I'm doing the tappet clearances at the moment. I have carefully measured each clearance with my brand new Suzuki feeler gauges, noted the size of the shims and ordered the correct sized replacements. Only when I do install the replacements the clearances are still out.

With a couple of the valves I put in a 2.45 shim and find I have too much clearance so I use a 2.5 only to find I have too little clearance. Hey? That's not fair! I can only assume that some of the shims have worn enough to be too thin. I am doing everything exactly as per the manual and I put oil on each shim, crank the crankshaft to make sure it's sitting properly before I measure.

I also find that I have to set the lobe of the valve cam I'm measuring to point straight up because if I measure with it straight up and then the same lobe pointing at 180 degrees to the shim I get different measurements. So I do all of them at the same angle.

Anyway I was hoping to have it all done by now but it seems I need to find myself a whole heap more shims now. I already had to order a bunch in at my local shop because they didn't have the ones I needed in stock. And to cap it off I tore the gasket I just put on while taking off the valve cover.

I know there is a shim club and that's a great idea but I live in Australia so it's one extra hassle...

[tom203]

JimmyR said.....
" I know there is a shim club and that's a great idea but I live in Australia so it's one extra hassle... "

At this rate, you be able to start your own shim club! Why don't you aim for a little more clearance for starters, then later on become a perfectionist (unlike me).

[JimmyR]

Well I'm no expert but it would seem to me that more clearance would be better than less. But I would really like it to be right!

[koolaid_kid]

Are you going by the numbers on the shim or are you actually measuring them with a micrometer or caliper? I find they are never quite what they claim to be.

[Steve]

I also find that I have to set the lobe of the valve cam I'm measuring to point straight up because if I measure with it straight up and then the same lobe pointing at 180 degrees to the shim I get different measurements. So I do all of them at the same angle.
...

In that case, you are doing it WRONG.

You did not mention what bike you have, but I am going to presume it's a four-cylinder bike. Start with the exhaust valves on #1 and 2. Those are on the LEFT side, under your clutch hand. Set the lobe of #1 so it is FORWARD, the lobe of #2 will be UP. In that position, without moving the crank, check the exhaust valves for #1 AND #2.

Rotate the crank 180 degrees (1/2 turn), you will see that the intake valves for 1 and 2 will be in position. The intake lobe for #1 will be UP, the lobe for #2 will be REARWARD. In that position, without moving the crank, check the intake valves for #1 AND #2.

Rotate the crank 180 degrees (1/2 turn), you will see that the exhaust valves for 3 and 4 will be in position. The intake lobe for #4 will be UP, the lobe for #2 will be FORWARD. In that position, without moving the crank, check the exhaust valves for #3 AND #4.

Rotate the crank a final 180 degrees (1/2 turn), you will see that the intake valves for 3 and 4 will be in position. The intake lobe for #4 will be UP, the lobe for #3 will be REARWARD. In that position, without moving the crank, check the intake valves for #3 AND #4.

Yes, your readings will be different than if you measure them with the lobes at 180 to the valves, but these will be the correct readings. The reason for these positionings is that in these positions, neither lobe is pushing on a valve, which will skew the cam in the bearing on that side of the engine. If you move the lobe to point away from the valve, the other lobe might be pushing on a valve, upsetting your reading for this valve. Yeah, it's only a tiny bit, but it's enough.

.

[john82q]

Aus shim club

Jimmy,
Post up what shims are you are after and I will see what I have.

Do it the way steve says which is also described with some pictures in the service manuel. which you already down loaded from http://members.dslextreme.com/users/bikecliff/
didnt you?


Cheers John

[JimmyR]

Well I read Bikecliff's version and also read the manual's version. In the manual it states that the lobe must be somewhere between upright and 90 degrees from upright away from the valve. I doesn't state that it must be in one particular position only. So that's why I took my measurements with all the lobes at the same position - I thought it would be more accurate. As far as I am aware I am still doing it right. FWIW the bike is an '82 GS1100G. I have a hardcopy of the original service manual.

However I am more than happy to do it however it will make the engine run the best!

As yet I don't have a micrometer but I suspect that I will have to get one as otherwise I will never get it right. I'm just a bit peeved because I am used to doing things by the book and getting the result I want. I have had others supposedly do the job only to fins that they did a poor job.

Thanks heaps for the suggestions guys - I will get myself a micrometer and follow your lead. Hopefully I will get it right. And thanks John - I may well take you up on your generous offer.

[MisterCinders]

Steve's instructions are exactly what the book (i.e., Suzuki Service Manual) says.

[JimmyR]

But it's still bloody hard! :-)

[Nessism]

But it's still bloody hard! :-)

The Suzuki service manual procedure is very specific as to how to position the cams. You have made life difficult for yourself by not following the specified procedure.

When buying shims it’s best to first take an inventory of what you have installed so you can anticipate the next adjustment step. The clearances always goes down so (for example) if you have a 2.60 presently, make sure you have a 2.55 (and 2.50) in case you need them. Also, even though the spec range goes to .08 mm, it’s safe to run up to .10 mm if that makes life easier. You will do well to have enough shims on hand to go two steps for each valve. Also make sure you have a spare valve cover gasket.

Good luck

[koolaid_kid]

... Also make sure you have a spare valve cover gasket...

This is very important. While they can be reused several times, if you tear one while removing/installing it you want to reach to your spare immediately.

[landshark]

I know there isnt as many Aussies on here, but there is no reason we couldnt start our own shim club?

i have some 2.60's in the shed.

[MisterCinders]

But it's still bloody hard! :-)

That's what she said.

[Guest]

I know there isnt as many Aussies on here, but there is no reason we couldnt start our own shim club?

i have some 2.60's in the shed.

True! I've got some spares here too actually... 2.40, 2 x 2.55's, 2 x 2.60's, 2.65.

So far I've used Precision Shims in Melbourne for purchasing... $9.50 or $9.95 each or something like that...

[Big T]

But it's still bloody hard! :-)

Get yourself a cheap Chinese caliper, we pay $10-15 here in the US and measure the shims, use a marker and write the size on the bottom of the shim

Do you have Steves spreadsheet? A really good tool, especially since you will already know next time what shim you need, because you'll have a record of it, no more pulling every shim

And Jimmy, isn't it about time you updated your signature to include your bike?