The valve clearances

Checked the valve clearances. I left the spark plugs in, hopefully that didn't affect things. The only valve in spec was the #2 exhaust valve. Everything else had little to no gap at all. I could only get the .038mm gauge through all of them. (Yes I'm going to get a metric set this week).

What causes this issue?

According to the service manual the pads must be replaced using a special tappet adjusting tool. Is there another way to do this?

 

The cause of clearances closing up (counter-intuitive, as you'd expect them to open with wear I know) is the microscopic wearing of the valve head & seat due to the constant hammering they get combined with no lead in fuel to "cushion" and lubricate.

This causes them to close faster than wear in other components can compensate for, I believe due to the angled contact area allowing the valve to sit (for example only) .005mm higher for .001mm wear...

That's my theory out of the way, now onto the tool. You can technically use a large zip-tie through the spark plug hole to "trap" the valve that you're working on open, and there's a description of how to do it somewhere on here that I'll look for now.
However, it's probably easier to use the correct tool to do the job once you get into the swing of using it.

P.S. No, having plugs in won't affect valve clearances, as long as the cam lobe is pointing directly away from the shim you're measuring it's fine. You may find with your metric feelers you get different results but they do sound pretty darn tight!


EDIT-: I can't find the thread where the zip-tie method was shown, but did find this post...

So, chacal sells the tool for a price that'd be daft to risk not using IMO

 

Okay,

So basically I need to replace the pads with thinner ones right? I don't suppose this is a universal part eh?

 

Why can't I just remove the cam shaft to get to the valve shims? Also, here is one description of the zip tie trick. http://www.imrisk.com/yamaha/xjwiretie.htm

 

You can remove the cams I guess, but wouldn't recommend it, not to mention most people don't want the hassle of making sure they kept the timing, re-setting the tensioner, worrying about stripped cam-cap bolts, keeping caps in the right order etc AND when you fit a new shim you really need to turn the cam to help seat it, plus the fact that you can instantly check your new clearance is correct before continuing For the money I'd say the proper tool is well worth it.

Yes provided the clearances are indeed tight when checked with metric gear you need to use appropriate thinner ones, not a "universal part" no, but Dave Fox (member "hogfiddles" on here) runs a shim bank so you don't need to buy new ones just swap for what you need. We're a helpful bunch here lol

 

i noticed that motion pro tool still "nicks" the outer edge of the shim bucket. so basicly parts of the head

and here is the detailed explanation on doing valves on XJ's with great pictures.

http://xjbikes.com/Forums/viewtopic/t=1 ... rence.html

 

You got to take note of your clearance measurements for each intake and exhaust valve for each cylinder, the most left cylinder (when sitting on the bike) is #1. Then you have to remove, let's say, cylinder #1 exhaust valve shim and flip it to read the number stamped under. Take note of this number and put it back in. Repeat for cylinders #2 to #4, then do the same for intake valves.

Then, if you are not confortable with the clearance charts, we could help you finding the shims you need.

 

yea but give them to the guys on here in metric, i gave mine in standard and it was all messed up.

 

The one I highlighted is the XJ4ever one, isn't that different, copied from the Yamaha tool? :?

And that write up of Fitz's you linked to is much better than the one I was trying to find! Using the right tool as well

mmcgee, I'd recommend you read through that to give you an idea exactly what you're aiming to achieve, it'll make life a lot easier...

 

I believe these were the Threads that you were looking for bloke,

http://xjbikes.com/Forums/viewtopic/t=14827.html

http://xjbikes.com/Forums/viewtopic/t=29209.html

As the others have said, you don't NEED the tool that Fitz uses in the first link. Personally when I did my valves this past winter I used some really heavy string trimmer line that I had laying around. Just put that in the valve while it was open and was able to easily get the shims out. Hardest part that I had was getting the buckets spun to get my small screwdriver in to pry out the shims. Other than that just take your time and get the most accurate measurements that you can and figure out which shims you have. Once you have that info send a PM to forum member Hogfiddles ( http://xjbikes.com/Your_Account/profile=1387.html ) Dave runs a shim pool. Tell him what you need and he will give you all the details of what he can get you. Good luck!

 

yea its a motion pro tool, you can get em anywere. it could of been cause i tighted my holding bot to tight and it pushed down on the aluminum to much

and you might be able to just go to the local shops with your old ones and trade them for new ones for free. at least that what they do for me around here

 

The second one was it osprey yes, the proper method is much better IMO just in case anything broke off inside the cylinder or too much carbon got displaced & stuck down the side of a ring groove...

EDIT-: @foolber, OK, I just thought Len had different ones made.

 

Here is a How - to video that helped me to figure out how to do it.

http://www.youtube.com/watch?v=V3gxT57eoDE

 

Normal wear. The shims and camshafts don't wear very much at all; what happens instead is that the valves pound themselves deeper into their seats causing the clearances to tighten rather than loosen.

This is why this is required maintenance (checking them) every 5000 miles. After one or two adjustments, they tend to "settle in" and you'll find that they only need to be re-shimmed occasionally, one here, one there. It's when they've been ignored that you find them all tight like that.

Take a close read through both of the above-linked articles. The photos in the second one will help you understand how the tool works; and also illustrate a safe way to do it without the tool.

If you have an aircooled XJ (I don't see an "X" in your sig) there's no reason to remove the camshafts to perform this simple maintenance task. (On the "X" motors, you HAVE TO remove the cams.)

 

Okay here are my measurements and shim numbers:

Intake #1: 0.127mm - 0.152mm y260
Intake #2: 0.127mm - 0.152mm y260
Intake #3: 0.076mm - 0.102mm y270
Intake #4: 0.051mm - 0.063mm y270

Exhaust #1: o.152mm - 0.165mm y260
Exhaust #2: o.152mm - 0.165mm y260
Exhaust #3: o.152mm - 0.165mm y260
Exhaust #4: o.152mm - 0.165mm y260

The exhaust valves are definitely in spec. I'm betting intake valves 1 and 2 are as well, though I will check with a metric feeler gauge a friend owns when I get a chance.

If I'm reading the chart correctly, I need a y265 for intakes 3 and 4. Will somebody double check me please?

 

Why do you have a range on each spec? If the .127 feeler goes and the .152 doesn't then it's .127. What are you trying to tell us?

 

But what if it's .137? or .142?

Point is, clearance needs checking with metric feeler gauges to have any hope of getting your valves in spec without the confusion of "go-no go" techniques & basically guessing what range of clearance you could have with imperial gauges with metric equivalents..

 

The shim chart in the service manual is listed with ranges.

 

There is a certain amount of uncertainty in any measurement. Even with the metric gauges, is it 0.12 or 0.127? If the actual clearance is 0.127 then you'll get the most accurate result with the imperial gauges. In any case you're limited by the tools you have.

That range is to assist you in identifying the shim that brings you into spec. There still is one best measurement of the clearance, which is the gauge that goes in, but has some drag.

 

Exactly, there is only one measurement not two. And with metric gauges you can get that measurement a lot easier & more accurately than with the bigger jumps between imperial feeler sizes (hence the need for the go/no go technique) and effectively guessing that the "real" measurement is in the middle (or at the lower range as you did)

mmcgee, The ranges are for the set clearances to be within, you have ONE measurement for the ACTUAL clearance (i.e. .10mm) and then you know if you're in or outside the RANGE required & (for an inlet showing the above .10) drop down a shim size to give you .15mm

EDIT-: To answer the original question by the way, you will either need a 265 or 260 for the 2 definitely tight, but can't tell for sure with the go/no go & only proper metric measurements could confirm which would be best

 

These measurements aren't accurate enough. Please go metric.

For example, the measurement for the #4 intake valve should be more accurate, you have to know if it is 0.05 or 0.06, becuase you will need a different shim if it is 0.05 (260) than with 0.06 (265).

If the correct measurements for your exhaust valves are actually between 0.15 and 0.16, they aren't in specs, they are all too tight. because specs are from 0.16 to 0.20 so you would need four 255 shims.

 

Intake #3 needs one size smaller shim (265)
Intake #4 probably needs two sizes smaller (260) put a 265 in it and re-measure.
And the exhaust valves are NOT in spec; they all need one size smaller shims.

As mentioned above, a purely metric feeler set such as K-D Tools' pn 2274 would make this much easier.

 

Well spotted men! 8) saved Mr. Mcgee some burnt valves there I feel *hands out the virtual beers*

My head was all tied in knots moving the decimal places about & rounding down the 3rd points and I completely missed that "minor" point

 

Cool. Thanks for the help. I don't know what I was thinking with the exhaust valves. For some reason in my head I had the bottom of the spec at 0.15mm. Dufus!

 

Hey we all make mistakes (see why we get on your back about metric feelers though lol ) at least the guys spotted it before the motor went back together & you had to strip it again... Now that would have been annoying :?

You've been put onto Dave "hogfiddles" for the shims I take it? When you know for sure which ones you need, he runs the shim bank and can sort you out