Fun with valve shims

[bg241ihc]

I have been referring to many of the posts here about valve adjustment and am now deep into it. Using many of the calculations metric and inch along with the table from the Yamaha service manual I have come to the following conclusions. My valve clearance table looks like this.

EX Current shim 3.00 2.90 2.80 2.90
EX Measured gap .102 .178 .225 .102
EX Replacement 2.85 2.85 N/A 2.75

IN Current shim 2.70 2.75 2.80 2.85
IN Measured gap .050 .102 .050 .050
IN Replacement 2.55 2.65 2.65 2.70

Any comments on the values would be welcome.

As I said, I used a variety of checks, but I did finally default to the table which seemed to be corroborated by the other methods +/_ one size in some cases. I figured in the end that Yamaha knew what would work, so decided to go with those results.

I used the cam loosening method and found it to be quick and easy and would recommend it. I did not have the special tool so cannot comment on that method.

I did find out a couple things that I did not see in any of the posts.

1. With the cam loose, there are a couple of lobes that are still somewhat depressing the associated valve a bit, so prying up on the cam a little is necessary to snake the shim out from the outer side of the cam/engine.

2. The shims are snug in the bucket so it is a must to find the small notch in the bucket and use a screwdriver to pry out the shim before pulling it out with the magnet.

Here are a couple of random shots for your enjoyment

Here is the magnet extracting the shim on the right and the screwdriver pointing out the notch on the left



The same thing from the other angle



My daughter was in the house playing the SIM's and was in the shop playing the SHIM's



BTW, Can I take advantage of that shim sharing library that I have seen mentioned?

[CatatonicBug]

Very nice. I like the SIM's/Shims reference!

Unfortunately, last we heard, the Shim library was disbanded. Many folks have extra shims laying around, so you may be able to do some random swapping and get what you need. They are usually available from your local dealer for a relatively reasonable cost as well.

[DiverRay]

All I can say is use the chart from the book, and VERIFY the clearance BEFORE you put it all back together. From how far out you are, I would think it's been quite a while since the last check. Most of the time, two sizes is ALL it takes to get back in line, and some of yours need three! As you set them up, remember with this bike if you can hear it a little, that's OK. they WILL close up as they wear, so on the loose side is better than on the tight side.
Also, be sure you have the shims installed with the numbers DOWN, so you can read them next time.
The Kawasaki 250 dirt/street uses the same size shim, IIRC. I have a local shop that will swap shims for $1.00 ea. that I use. IF you can't find anyone local, I can check my stash and see what I have. Send me a PM if you need a swap, and I'll see what I can match from your calculations.

[natemoen]

Ford Taurus SHO from the late 90's also used the same 29mm shims but last time I talked to a Ford dealer about the shim he wanted $25 for 1 shim.....but eBay has them as well. I got a decent collection of 12 shims and the tool for $13 on eBay as well so there is deals to be had for shims.

I might have something you need as well and could possibly trade shims too, let me know.

[bg241ihc]

Thanks for the tips and advice. I was not surprised that the valves were so far out. I just got this bike in the fall as a somewhat running project. I am sure the guy I got it from knew little about servicing the bike.

It looks like I can reuse the 2.85 on the intake side for one of the two needed on the exhaust. If anyone wants to swap for any of the others, reply or send a pm.

Thanks

[Rasputin]

I also have about a dozen shims and quite a few more available from a friend close to here. Let me check what all I have. The other thing is your location as those who are closer will probably be faster as well. Canada post is not known for speed
Also if you have not yet then you should double check what you need. It is very frustarting to wait fro the mail only to find out you missed by one shim size. DAMHIK

[Incubus]

FWIW, when I regapped my valves last summer I got the replacement shims, swapped out for free, from a local Honda dealer. I have no idea what Honda they might fit, but they fit the XS.

Check local folks first. Folks are still hurting and more than willing to make swaps like this now for the chance at your business later.

Patrick

[dpotter58]

ding this guy and see what he has. Shims

He's pretty good about swapping.

[Rasputin]

I have these shims available for swap. Postage cost only...
2-2.55
2-2.65
1-2.70
4-2.75
1-2.80
1-2.85
2-2.90
1-2.95
1-3.00

[bg241ihc]

Thanks for the responses. I have a good lead on a couple of sizes and if necessary will hit some of you up for those I cannot locate.

Thanks for all your excellent help and comments.

[cowboybob998]

All I can say is use the chart from the book, and VERIFY the clearance BEFORE you put it all back together. From how far out you are, I would think it's been quite a while since the last check. Most of the time, two sizes is ALL it takes to get back in line, and some of yours need three! As you set them up, remember with this bike if you can hear it a little, that's OK. they WILL close up as they wear, so on the loose side is better than on the tight side.
Also, be sure you have the shims installed with the numbers DOWN, so you can read them next time.
The Kawasaki 250 dirt/street uses the same size shim, IIRC. I have a local shop that will swap shims for $1.00 ea. that I use. IF you can't find anyone local, I can check my stash and see what I have. Send me a PM if you need a swap, and I'll see what I can match from your calculations.

I have got to do this some day so i am reading about it now, but help me out here because i am haveing a hard time understanding something, how is it going to tighten up later on if it is louse, thats the problem now one valve is makeing to much noise, as these shims wear do they not get louser ?

[bg241ihc]

Like most who do this for the first time, I was wondering the same thing. There is so much good information from many experts on this site that I hate to try and re phrase those who have gone before us.

Do a search on "valve shim" in this forum and you will find a multitude of posts to answer all questions about this. Not only will you get several excellent perspectives to see from, they also offer a lot of good reading.

I don't want to shrug off your question, I just want to bow to those who have already given us this knowledge

[natemoen]

fast and dirty answer is that the valve starts to seat down into the head farther so it closes the gap at the cam lobes.

[cowboybob998]

fast and dirty answer is that the valve starts to seat down into the head farther so it closes the gap at the cam lobes.

Not doghting what you say but this is just how my brain works, if it was a new valve i could see it seating down into the head but a motor that is allready broke in i cant see the valve moveing that much, maybe a little exspantion when it heats up, oh well i will just take your word for it that you have been there an done it and i have yet to go there, its cold outside and i have to much time to set here and think, lol
thanks
Bob

Ya got me thinking again, the ticking noise that i hear is on the right side exhaust valve, could it be the lifter instead of the shim, only one makeing noise like it is.

[CatatonicBug]

It's not the shim that wears. That's why you can swap the shims and re-use them later. The thing that "wears" is the spot where the large (bottom) end of the valve meets the engine. As it slaps against the engine, the valve and the aluminum engine case slowly wear, allowing the valve to ride higher up toward the cam, raising the shim. This is why, over time, you need smaller and smaller shims.