ok so i just checked my clearances.

here's what i got.
Right intake.  I can get up to a .06mm gauge under it.  Feels better at .05.

Right exhaust.  I cna get up to a .06mm guage under it .  Feels better at .04.

Left intake.  Can't get my .04mm under it , that's the smallest gauge i have.

Left exhaust.  can't get my .04 under it either.

So it seems to me that the right side is fine.  Looks like I"m gonna have to pop the shims on the left side and mic them.  

I don't have time to do that right now, but I'll get to it later tonite.  I guess my question is, do I need to do the shims on the right side as well or just leave them be.

jake

Your right side shims are fine...  Just replace the left side ones with smaller shims.  Most likley the next size smaller.  If they are factory shims they may be a strange size though, the ones you buy will be in .05 increments.  Factory can come to the .01 for a perfect fit when you buy it.

so if i change the left side by .05, they will be right around .08 because they were too tight for .04. Is it ok to have the right side being around .05-.06 and the left side being around .08?

jake

Quote from: jake42so if i change the left side by .05, they will be right around .08 because they were too tight for .04.

Hmmm - not so fast.

If you can rotate the bucket that the shim is sitting in by hand then you're most likely OK for now.  If you CAN'T rotate it then there is NO clearance and you don't know HOW much to reduce the thickness of the shim.

Jake, I included the thinnest-available shim in that package for just this eventuality.  Pull your current shim, put that smaller-than-normal-diameter one in, and measure the clearance.  (Sorry, I may not have included enough feeler blades to fill in the gap.  :x  But you can find a full set for a few dollars at an auto parts store.  richard just picked up a metric set ... down to .04mm ... yesterday at Pep Boys.)  Once you know the shim thickness and the clearance you can consult THE CHART to determine the desired shim thickness.  If you're lucky you can reuse one of your shims in another location, but I wouldn't hold my breath.

Quote from: jake42Is it ok to have the right side being around .05-.06 and the left side being around .08?

Yep, no problem there.

Kerry,

Thanks for the info. I have all intentions of pulling hte shim and trying out your thin one. Just didn't have a chance to get to it tonite.  If you wondering why i'm posting this now, it's because i just woke up and now i'm headed to bed for real.

Jake

Well I couldn't go bak to sleep without tinkering a little and this is what I found.

I pulled the left intake shim and it was a 2.65.  So I dropped the 2.60 that you had included in your package and remeasured.  With the 2.60 in place I get a clearance of about .06 now.  So it  looks I'll go with a 2.60 for that one.  Too tired to try the left exhaust one tonite.

Jake

Quote from: jake42With the 2.60 in place I get a clearance of about .06 now.

I forgot all about the other shims I sent.  (Duh!)  I'm glad one of them fit OK.  

Quote from: jake42Too tired to try the left exhaust one tonite.

Understood.  Those are a little tougher to get at than the intakes.

Good Luck!

kerry,

glad you're on.  I'm going to go check the exhaust one in a minute.   The feeler guages are a little tricky sometimes.  what i came up with is I started with the smallest and worked my way up until I couldn't fit one anymore.  Turns out I have my own set of gauges that came with a cheapo tool set that I got for christmas last year.  After I put in the 2.60 the largest I could get through was the .06. Hope that makes sense.  Now I have to find a place around here where I can get shims so I don't have to order them online.

Oh, in order to get the intake shim out I had to loosen the bolts around the cam shaft .

Jake

Kerry,

Just checking what your homemade test shim was.  I miced and came up with about 2.14-2.15 area.  So I popped that in and got a cleraance of around .28-.30.  According to the chart that will bring me down from 2.62mm that's int there now to a 2.40mm.

Does my math sound correct.?

jake

Quote from: jake42Does my math sound correct.?

It DOES sound correct.  As you can see on the chart, the thinnest shim you can buy is 2.15mm thick, so that part sounds right.

But the final result is kinda surprising -- it's worse than richard's 4-thickness jump(!), which was also on an exhaust valve.

Still, if you made sure that the dial calipers were zeroed out after shipping, and you measured everything 2 or 3 times, and you used 25.4 as the multiplier (if you're using the 1/1000" scale on the dial calipers) then I'd say you're right on.

I dare say that when you put the right shim in there you will FEEL a difference in the how the bike runs, and in the power available when going up hills, etc.  At least, that's what richard reported.

I only wish that I'd had a 2.40 shim to include....  :dunno:

well you made me nervous so i went back and checked the calipers again.
they're good.

I also rechecked clearances again with the new test shim in place.

i put my .20 and .08 together and can get it in there with just a little drag.

I can also get the .30 in there with a bit more drag

I put the .30 and .10 together and can get it in there but it's a really tight.

So now i'm starting to confuse myself. I don't know if I should try and get a 240 and see what happens.  I mean I know I'm starting to introduce a lot of measurement error by putting gauges together and putting them through.

I put up another post to see if anyone will send me some shims so I can test some different sizes, so I don't have to by everuythign between 240 and 255.

jake

Sounds good.

Just one more question, for curiosity's sake.  When you stack the .20 and the .08 blades, what is their combined thickness according to the dial calipers?

they are just a hair over .28 together.  So from those numbers do you think I'd best be served by going with .28-.30 as my clearance?  

jake

Quote from: jake42do you think I'd best be served by going with .28-.30 as my clearance?

Yes, but as you know those numbers span the boundary between the 2.35 and 2.40 shim thicknesses on the chart.  So the hard part is deciding which to get.  You might want to get both.  After all, that particular valve seems to be "on a roll" as far as getting tighter.

I will tell you this:  With richard's similarly-off valve we were able to force just about any blade thickness in there.  We were stymied for a while ("Which is the REAL clearance?") until we realized that we were actually pushing the shim away from the cam when we went too thick.  I guess I'm leaning towards the 2.35, but only you can say when the drag on the blade is "just right".

Cool, check this out.  I called a bunch of dealers today and eventually wound up driving to one like 25 miles away and they had a box o' shims.  I managed to get a a 2.40, 2.45 and 2.50 for a whopping 7.95.  Now if I just get some time tonite to start swapping.

Jake

Ok,

So here's where I stand on the clearances now.

RI.  dropped from 2.68-2.65 and clearance is now .05-.06
RE. didn't touch and clearance is .05-.06

LI - dropped from 2.65-2.60 and clearance is .04-.05
LE - dropped from 2.62-2.50 and clearance is .08-.09.

Here's my question. I can get the .10 blade under the LE now with the new shim in.  It's tight and more than what I assume is a little drag.  >08 seems to slip under with almost no drag.  So I'm assuming I'm somewhere in the .08 maybe .09 range.  Do I need to come up to a 2.55?
. What is the consequences of this one being maybe a little looser than recommended?

Jake

I would say to go ahead and drop in a 2.55 (I know I know, another 50-mile round trip ... and not on the bike  :x ).  That way you will still have the 2.50 to drop to when the time comes.

I couldn't really say what the consequences of a slightly too-loose exhaust shim are.   :dunno:   Maybe one of the real engine gurus could venture some wisdom....

Here's a thought: If you decide to go back to the shop, bring your calipers with you.  Since they have a "box of shims", you might get lucky and find a 2.52 or 2.53 or something!

I think that I read a thread here, where someone (a racer? or Srinath?) suggested that it was better, performance-wise, to keep the valves adjusted towards the tighter end of the spec (and maybe even a tad tighter than spec, so long as it's not binding).  I can't remember if that was only for intake, or only exhaust, or both.  If you use the thicker shim, you should have clearance between .03-.04, which would be in-spec, towards the tighter end.  

It's possible that you won't see too much wear in the future;  GSJack has described the wear pattern as non-linear (for example, lots of wear during the low-mileage years, then less).  So if you're an optimist, the thicker 2.55 shim shim may last you for years.

On the other hand, if your bike has (say) 30k miles on it, and the "ideal" shim size has gone from 2.62 down to 2.52 since new, then if the wear were linear, you're wearing at a rate that will bring your clearance down to a nice in-spec 0.07-0.08 within 3k miles.  If you are a pessimist, you might choose to weather a bit less performance for a few thousand miles, in return for having an extra 15k miles of riding before the next shim swap.

BTW, you might also post and ask if anyone has a shim which is a tad thicker than 2.50.  Even 2.51 would get you in-spec or pretty close to it.

picked up the 255 tooday. Had to drive through the remnants of tropical storm frances to get it.  I'll drop it in tonite and recheck the clearances.

Jake

BINGO!

The 2.55 put me right around .05mm on the left exhaust clearance.


Just gotta bolt the oil pan up tonite and wait for it to quit raining.


Kerry I owe you a box of Krispy Kremes.  

I'll be sending all your tools back tomorrow

Jake