So I'm checking the valve clearances on my 07 GSXR 1000, 18k miles. 500 race miles. No longer going to the track. EXHAUST are on the tight side of spec at 0.178 mm in a range of 0.18-0.28 mm. INTAKE are good at 0.127 mm in the spec range of 0.08 - 0.18 mm. I do have a manual and I've read as much as I can about this. I read that it is normal for the EXHAUST to become tighter than the intake. Correct? Do I leave the INTAKE clearances as they are? They seem good to me. And with the EXHAUST, should I stay on the upper end of loose or shoot for the middle of the spec range? Finally, as far as the 'feeler' goes. I don't want to force the feeler in...it should go in with some resistance but not 'catch' when I pull the feeler out.? I know this 'feeler' feeling, comes with experience. I have some, but it's been years since I checked any valves. Never kept a bike long enough to worry about it. Not sure what I'm looking for here, just some confirmation that I know what the hell I'm doing? :up:
It's normal for any valve clearance on an OHC shim under motor to reduce. I've seen both ways. If you are going to go to the trouble of pulling the cams, it only takes 10 minutes to do the intakes. The time involved is all in disassembly and assembly. If you are putting the bike on the street set them all loose. It should slide in and out without forcing it. Slight resistance is ok. (If a customer brought me that motor I'd tell them:" You can leave the intakes but you would be a FOOL not to change them while the cams are out.")
EDIT original post: "No longer going to the track, with this bike." Afm, so I should loosen the intakes up? Shoot for 0.15-0.16 mm? I understand it's easy enough to do since I'll be doing the exhaust anyway. I've lotsa time...no rush at all...but I'm damn near in the middle of the spec range now. I'd like to know what the tolerances were from the factory, just to see how much they've changed. How about a manual cam chain tensioner? recommended? Not worth it? Also, what about the PAIR valve? Trash it and get some blockoff plates? Haven't really researched it yet.... Motor is stock with M4 slipon and filter.
Factory typically is at the loose end. If spec is .18 put them there. That's probably where they started. No opinion on manual CCTs. No opinion on pair, but if you get rid of it be sure you crankcase is vented somehow.
So, got the cams out. Removed each shim, one at a time, recorded its size on paper and put it back with the bucket. Looking at my manual and the shim chart, it gives me the needed shim to put me back in the MIDDLE of the spec range. If I want to go bigger or 'looser' in the spec range, how do I determine how big of a shim to buy? For example, if an exhaust valve measures 0.178 mm with a 1.60 shim, the shim chart shows I need a 1.55 mm shim which would put me in the middle of the spec range. So, should I go from a recommended 1.55 to a 1.80, 1.85, or 1.90?....which would put me in the upper 75% of the loose end in the spec range? Am I making any sense for yas? I don't want to buy 40 different shims. I feel like I should be able to get the exact size of shims that I need for each valve when I go to the local dealer.
If you put a 150 shim in there, it will be at .278, loosest within range. You normally have to buy shims in packs of five minimum. They are pricey. Try to find a dealer or shop that will trade you for your old ones.
When I adjust valves I use thousands of an inch for measurements as it is easier for me. The difference between the shims is .002" when going from a 150 to a 155. I set them all to the loosest factory spec given. I set them all the same. I have all the half sizes to get them perfect.
I'm looking at the manual again, and with a measured exhaust valve clearance of 0.178 mm and a current shim of 1.60 mm, it will put me in the middle of the spec range on the chart? What am I missing here?
Put the chart away. If your clearance is now .18mm with a 1.60mm shim, and you want to get to .28mm (loose), add .10 mm to the clearance by putting a shim in there that is .10mm smaller. It's third grade math.
Yeah, I was gonna ask if the chart is, not necessarily wrong, but not used in the real world? Anyway, here's the damn chart for the hell of it... 0.18mm-0.28mm is the range. According to this, the needed shim is a 1.55 and that puts me in the #9 slot out of a possible 21.
If I go with a shim, smaller than what the chart says, that will take me out of the spec range on the tight end, since I'm right at the 'tight' border for the exhaust. All the exhaust were .178 mm.
I've never used one. I had a customer trying to use it last week call me and ask about what shim size, and I told him the same thing I told you. Put it away and just do simple math. I guess since I do it every day, it's different, but I never saw any use for those charts.
1.Measured clearance 2.actual Shim Size 3.Desired clearance 4.Correct shim! 1 + 2 - 3 = 4 4 won't be correct unless you buy factory shims, them come in smaller incriments of .01mm. After market will be in half sizes. I use Hot cams you get more for your money! and get yourself a Micrometer or a digital Slide, they aren't always correct in thickness. especially use ones, it will save you time measuring them before installation.
Damn it Rick. Rick right? I know your creds so I'm not necessarily questioning what you're telling me, just trying to understand. What you're telling me just doesn't match what I think I'm reading and understanding in the chart/manual... Show me the light...
I do plan on measuring the current shims before I buy any. Shims in the bike are factory. Local dealer has shims, I don't know if they're genuine suzuki or not. $5 each.
using the numbers you posted .28 is the clearance you have "checked with feeler gauges" 1.55 is the present "shim in the engine" add those 2 together you get 1.83 subtract .18 and you have 1.65 this is just a reference in how to do it! that's all don't use simple math as rick said! 1.55 + .28 = 1.83 - .18 = 1.65 it's that simple
No, the present shim is 1.60, not 1.55. No, the present measured clearance is .178 not .28. Measured exhaust valve clearance - .178 mm Current shim - 1.60 Correct shim to bring me in the middle of the spec range according to the chart - 1.55