Valve Shim Clearances: Please check my #'s

I got a hold of a new 32 blade metric feeler gauge set for $8.50. At the same bike shop, I saw an old tool package on the wall that turned out to be the shim bucket tool. Paid $10.00 for it. 8) So, I checked my clearances and recorded the shim sizes. Thanks to Fitz's Valve clearance thread, it was a walk in the park.

Everything went smoothly, EXCEPT, the bucket tool refused to work with the #4 intake valve. I tried it 9 times (truthfully) but the tip of the tool always would not hold the bucket. Took the tool off and tried it on other buckets and it worked perfectly. Unfortunately I had to use the shielded copper wire method on that valve (I too do not like the thought of disturbing the carbon or the valve seat).

Cyl ~ Intake ~ Exhaust
1 ~ .09, Y260 ~ .10, Y260
2 ~ .09, Y265 ~ .16, Y265
3 ~ .08, Y260 ~ .11, Y260
4 ~ .06, Y260 ~ .06, Y265

1 out of the 8 is within spec (the minimum at that)
After consulting the chart, I should replace them with these shims giving me the new clearance of:

Cyl ~ Intake ~ Exhaust
1 ~ Y255, .14 ~ Y250, .20
2 ~ Y260, .14 ~ GOOD, .16**
3 ~ Y255, .13 ~ Y255, .16**
4 ~ Y255, .11** ~ Y255, .16**

** should I go to the next size shim?

Please look over my #s. It's dizzying looking at that chart. :roll: Thanks

 

You are the closest XJBikes member I've seen to my location, and we have the same exact bike. That's cool.
Yes your calculations all look correct to me. Nice work.

Since these valves get tighter with age and you would be at the tightest spec on those in question (**), I would go on down to the next size shim and put them just out on the loose side. When I re-shimmed my valves, they didn't go out the full amount of the shim except for #4. Here's my results.

Intakes were all .10mm so I went down one shim size and they went to:
#1-.13mm, #2-.13mm, #3-.13mm, #4-.15mm

Only re-shimmed #1 (.12mm) & #4 (.10mm) exhaust and they did this:
#1-.16mm, #4-.20mm (from 275shim to 265shim)

If you put them at the tight side of the spec, you will likely be ordering new shims pretty soon. After changing mine it all seemed fine (all measurements went down expected amount), but I ran the motor for about 100miles and rechecked and that's when I noticed they were a little tighter than I expected. I will be checking about every 500 miles for at least the next few months and will likely re-shim #1 exhaust very soon. It would've been better to take it on out to .21mm in hindsight.

I had the same issue with the "tool" but it was on the #3 intake, second time around I made absolutely certain to center the tool (side to side) on the cam lobe and also used a bright light to make sure the lobe had pushed the lifter all the way down. Also cleaned the tip of the tool and sanded it with some 60grit to give it some bite-then no problems from there.

If your interested I posted a picture of the shim tools I made from a chip puller that worked amazingly good at popping and pushing my shims-made the job go 3 times faster. Here's the link (scroll down and you'll see them)

http://xjbikes.com/Forums/viewtopic/t=1 ... rt=30.html

 

MercuryMan - Where is NWA (northwest arkansas?)?

That's what I was thinking about those few that will be at the minimum end of spec. If that's what I do, would I expect some valve noise?

I know I had that tool perfectly on there like all the other ones; centered & pushed up against the cam. With it being #4 intake, I can see the tip down by the bucket due to the half circle cut out of the head at the end of the cam. When the bucket comes up, the tool doesn't even touch it (definitely centered and pushed to the cam). I even staggered the tool to each side as well just to try it. I thought about stacking a spot weld or 2 on the tip and filing it back down but I don't want it to interfere with the other 7 shims.

Nice job on those tools.

 

Yes Northwest Arkansas - AKA Wal-Mart HQ and Razorback land.

Well since the spec calls for .04mm of range whether its .11-.15 or .16-.20, it's only 25% (.01mm) out of the complete range at .16 or .21 and heading tighter.

Since they do go tighter over time and if yours haven't been done before (as tight as they were probably not), and I read the wizards on here right, they will go tighter pretty quick after this first adjustment-then progressively calm down and slow down on going tight.

I'm sure a wizard will chime in here soon, but my experience with the shims would have me going to the loose side not the tight. However I would not put in the next size down if it would take me to .22mm or .17mm. I did leave my .16mm exhaust there, but I plan on detailing my valve cover this winter so I'm going back in pretty soon and will check it again to be sure it's not tightened up any.

You could just go with the spec on the tight side and check them again soon. I found it strange that the shims didn't put my intakes at fully .15mm like they should have, so that's why I would have some concern about shimming them right up at the tight limit. But if you go by the book that would be the called for adjustment.

 

NO NO NO. You are correct; do NOT go two sizes so you go out of spec on the loose side, hoping for them to "come to you." You have them right.

The spec is .11mm~.15mm intake; .16mm~.20mm exhaust. Put them in spec. IN.

Then be sure to check them again NO MORE than 5000 miles down the road. If you'd feel better, give them about 2500 miles or so, and re-check. Don't run 'em too loose, in the range is in the range. You now know what shims are in there, so it's going to be much easier next time. You also know what valves may need to be re-shimmed and can even have the shims on hand. I say "may" because my '81 has an intake valve that's been at .11mm the last three times I checked the clearances. Apparently it's happy.

These big changes in valve timing are going to "drive" a carb re-sync, don't forget.

Oh, and about the tool refusing to work; did you see "Part Deux" wherein I explained why the tool fails sometimes and how to make it work every time? http://xjbikes.com/Forums/viewtopic/t=29209.html The secret is centering it (side-to-side) on the cam lobe.

 

Fitz - I went over every detail in both of your threads (great write-ups!). I was very methodical about having the bucket fully bottomed out (cam lobe pushing against the shim) and centered side to side against the lobe. I only had that problem with the one valve. All the others went perfectly. I even went back and redid a few to make sure the tool was still working fine (the front edge of the tool tip had the surface scraped off from not holding down the bucket), it was. I can see how there is a chance for error but I did my best to combat that. I really think the tool failed.

About the resync, I haven't even tried to start the bike yet after the full carb cleaning and everything else I did. They are bench set and mixture screws set at 2.5 turns out.

 

Excellent. Float levels wet-set? Airbox boots in place, new air filter and brand new freshly gapped plugs? It sounds to me like this thing is close to ready to fire; I just noticed your sig.

These camshafts are only precise where they need to be, and somewhat lumpy-bumpy everywhere else. From what you're describing, the "backside" of that cam lobe is keeping the tool from positioning correctly. I wouldn't sweat it.

 

Yep. Wet-set the floats individually on my bench vise w/gas (leveled on all planes), new plugs all gapped at .63 & .65 (spec is .60~.70mm) & boots in place. I need a new air filter though. I'm not sure the one that was in it was correct. It only fits in the box by crushing the top down a bit and doesn't fit at the same angle as the hole in the airbox. Do the 650's and up use the same filter size as the 550's? Maybe the wrong size filter is in it. The foam on the filter broke down years ago.


Are there any timing things I can or need to check? I did the cam chain adjustment before rotating the crank forwards and backwards for the shims. Should I re-adjust that?

I'm gonna order a new air filter with the shims from chacal.

 

The 550 air filters are unique to the 550s; they "side load" the filter whereas the ones for the 650s go in from the top. The key to the 550's air filter fitting correctly is the wedge-shaped tab in the lid that pushes it against the opening.

Cam chain should be fine.

That being said, let me give you a couple of tips from a guy who's put two 550s back into service now:

At some point soon after you start riding it again, the cam chain tensioner body-to-cylinder block gasket will begin to leak; it will make you think you have a base gasket leak. Get a new tensioner body gasket from Len; and keep it in your parts drawer. Change it the next time you need to take the carbs off. There is also a rubber o-ring "squashed" into the pocket around the adjuster locking bolt, under the washer. WHEN it begins to leak, replace it as well.

At some point soon after you start riding it again, (sound familiar?) the tach drive will begin to leak. It happened on both of my 550s within a couple hundred miles of going back into service. Repair covered here: http://xjbikes.com/Forums/viewtopic/t=19538.html

I think both of these things start leaking because they get "baked" during the bike's initial service life; both of my bikes did it soon after being returned to service.

 

See I knew a wizard would show up. Go with what bigfitz said-he has WAY more experience with these bikes than I do. I had a feeling that my limited albeit unusual experience with my valves on the exact same bike as yours would be useless.

That being the case - still believe its better to have an exhaust valve at .21 and getting tighter than .155 and getting tighter. Can your feeler gauge accurately measure five one thousands of a millimeter? Is a prematurely opening and late closing exhaust valve better than one that stays closed but opens only slightly less than it should during exhaust? Did Yamaha not engineer any tolerance past their specs? Must stop pontificating-me??

Like I said go with bigfitz.

I will be checking my .16 exhaust LONG before 2500 or 5000 miles have passed. JSYK

 

Like I said, I believe it might have been in a different thread, I have one intake valve that's sitting at .11mm and has been for over 10,000 miles now. Since that bike has 27K on it, it's possible that valve is as "bedded-in" as it's going to get and nothing's really wearing.

My point is, you can't count on a valve you've intentionally shimmed loose to "come to you" quickly enough to make it worth doing it that way. The more miles the motor gets on it, the less they change, and fewer of them need attention each time. (Provided the motor is healthy otherwise.)

 

Ah I see your point now. So sometimes these valves will get fairly stable or even downright stable, I understand why you advised, go to spec. I thought they always progressed to tighter.

In light of this Yamaha should have made shims in more than just .05mm increments, .03mm would be nice to have, or .07mm. Thanks for shining the light as always.

 

If they DID, there would be more than one size shim that would put a particular valve within its specified range. As it is now, there is only one size shim that will put any given valve within spec, making the system somewhat "idiot proof."

Or maybe they were just trying to keep us from driving ourselves crazy over-theorizing.