Valve Shims

[Canadian FJR]

Can anyone confirm the stock valve shim size.
I assume they are all the same when new.

Also

I’m looking for a simple spreadsheet/schematic to record valve specs when doing the valve check.


Thanks in advance,
Canadian FJR

[rbentnail]

No, they're close but not exactly the same thickness. For replacements I use Pro-X shims. See, if you buy a kit like Hot Cams they come in .05mm increments. Pro-X shims are ordered individually but come in .025mm increments. Much easier to hit the clearance measurement you are looking for. Different folks adjust them different ways- I'm one that does it "wrong" compared to most people.

[raYzerman]

Thicknesses vary but the diameter is 9.48mm. I use Pro-X shims.
We use Yamafitter's special spreadsheet to document existing clearances and shims, will calculate required shim to get you to 70% of max clearance.
Have to email, it is an Excel file.

[Canadian FJR]

Just to be clear, the stock original (brand new bike) shims are not the same thickness??


Canadian FJR

[BkerChuck]

That is correct. They are NOT all the same thickness.

[Canadian FJR]

So that begs the next question, is the valve clearance for each motor check at the assembly line and then shimmed to spec?


Canadian FJR

[FJRoss]

So that begs the next question, is the valve clearance for each motor check at the assembly line and then shimmed to spec?


Canadian FJR

Yes. Clearances are set at the factory when the engine is built and there is a fairly narrow range of shim thicknesses. If I don't have the right shim, I will sand down an existing shim using wet carbide paper. Not a lot of point in buying a complete shim kit. The vast majority would be outside the range useful on an FJR.

[raYzerman]

While some shims will be the same, each valve for the most part has it's own unique shim thickness. Laser etched on one face, but double check with a micrometer if it's worn off.

[Auburn]

also you can most times use a shim that you pull out on one of the other valves. The last one I did, I moved 6 or 7 around and only needed a couple form the kit.

Definitely verify the with a set of calipers that the number etched on them matches.

[N4HHE]

Every shim and engine manufacturer cautions against sanding/grinding shims down in size. The shims are case hardened so grinding them down to something smaller puts you closer to the soft inner core. No doubt they are ground/polished during manufacture but there they know how thick the case hardening and therefore how much they can safely remove.

I don't understand the need for a spreadsheet? Shims come in metric size, generally 1.60mm to 3.00mm ever 0.05mm. Gap should be about 0.12mm to 0.24mm (don't trust me, verify, I'm working off memory of 0.005" (0.127mm) to 0.010" (0.254mm) gaps). How hard is it to decide what shim to use if you have a 0.10mm gap and a 2.60mm shim? A 2.50mm will put you near the other end of the adjustment range yet still in spec.

Is this math too hard for humans any more?

If the shim is 2.60 and gap is 0.10 then 2.70 will give 0.00 gap. If 0.24 desired then 2.70 - 0.24 = 2.46. 2.45 is closest but will give a larger gap than spec but perhaps that is good enough. 2.50 will be in spec and still have a lot of wear. Am guessing it will never need to be adjusted again.

[Intech]

Scott, pm me your email and I will send you the spreadsheet Billy Fitz made.

[FJRoss]

I don't believe that the FJR valve shims are case hardened. Too easy to remove material for that and there isn't much need for case hardening with a shim-under-bucket arrangement. This has been argued a long time (on many forums) and I have never found a definitive answer other than it worked for me. I put around 100,000 miles on my 2007 AFTER using "adjusted" shims with no issues. Subsequent checks did not reveal any noticeable wear on shims that had been ground.

My reason for grinding rather than replacing was local availability rather than being cheap - dealer didn't have what I needed and I didn't want to wait days to get them ordered. Added bonus is to get EXACTLY the target thickness rather than the increments offered by manufacturers - not a big deal but satisfies some of my OCD. I aim for about two thirds of the maximum clearance range because clearances get tighter, not looser as valves and seats wear. (Most shims are only available in 0.05mm increments.)

The spreadsheet is nice because it does make the calculations easy. More to the point, it documents the before and after and is a useful reference for the next check.

[raYzerman]

I have a shim kit that travels to tech days, have it stocked with in-between sizes of Pro-X. Don't think they are hardened... but I'm not into sanding them down either since Pro-X are $2 each. A bike shop may have a stash of shims you can work a deal with......
Based only on experience with so many, an FJR (and other bikes) is not likely to suddenly get tight clearances, it takes considerable time and big mileage to change .001". However, the initial setting by Yamaha may be nominal or a tad smaller, best get that first check info... based on all that, re-shimming to 70% max does seem to make the bike run better when you get them all the same, better TB sync, and I'll postulate you'll never need another valve check.
TB sync should never change much either unless clearances do.

Now if you ride like grandma, you may have other issues like carbon build-up on the intakes, can be leaky.... the only way valve clearances will grow larger...

[FJRoss]

Now if you ride like grandma, you may have other issues like carbon build-up on the intakes, can be leaky.... the only way valve clearances will grow larger...

Isn't carbon buildup more likely on the exhaust valves than intake valves?
On my '07, all the valves were fairly close to the minimum on the initial check. Very little change at the next check and a few adjustments were needed on the third. Never had to adjust any exhaust valves, only intake.

[Hppants]

I've done this job like 8 times on 4 FJRs. That doesn't make me an expert. But this much I have observed:

1. By far, the MOST common shims I've needed are 1.70 mm, 1.75 mm, and 1.80 mm.

2. If you have one shim out of spec on the cam, you might as well adjust all of them to the loosest 30% of the range. It might save you another adjustment down the road.

3. Now - the 0.05mm difference on the Hot Cams shims does present an issue. If the shim is not already within the loosest 50% of the range, then going down 0.05 mm will likely put it out of spec (again, kind of a math obvious thing). So, having the Pro-x shims might help that issue.

4. I tried to sand a shim with 600 grit, 400 grit, and 320 grit wet sandpaper. Shim laughed at it. Admittedly, I didn't try "carbide paper". Not really sure what that is, but since Ross cut the shim with it, I guess it is has some harder abrasives in it.

5. I'm with N4HEE on the math thing. The s/s is a bit confusing. I use my caliper and do the simple math for each hole. With the 0.05mm shims, it's really an exercise in affirmation. Too loose, go up one size (that's all you will be able to do anyway). Too loose, down one size. That's really it.

6. Although you didn't ask, I can confirm from my experience that you do NOT need to remove the timing cover to CHECK the clearance. The "non-lobe" side of the cam shaft is a perfectly round semi-circle. The clearance will be the EXACT same anywhere you check it during that part of the rotation. So put the bike in high gear, and rotate the back tire until the lobe is pointing up, and check it. If you have to move the cams, then you have to pull the timing cover off and you can verify your check then, but it won't be any different, I assure you.

7. Regarding carbon build-up, I'd be surprised of that is a factor, although I can't write scientifically. This motor runs hot. Those spark plugs are a toasted brown color and they are SPOTLESS after 25K miles. I have broken down one FJR motor with 90+K miles on it, and it had almost ZERO buildup of any kind in the intake and exhaust passages, on top of the valve seats, top of the pistons, etc.

[FJRoss]

4. I tried to sand a shim with 600 grit, 400 grit, and 320 grit wet sandpaper. Shim laughed at it. Admittedly, I didn't try "carbide paper". Not really sure what that is, but since Ross cut the shim with it, I guess it is has some harder abrasives in it.

240 grit silicon carbide paper. On a flat surface and use figure eight motion to keep material removal even. Check frequently on the edges and in the middle with digital caliper - you don't want a taper. Micrometer is more accurate but caliper is sufficient if you are careful and have good technique. I used a finer paper (400 grit?) to finish. Took 5-10 minutes per shim depending on how much material had to come off. Sanded the side with the size marking to prevent confusion on a subsequent check.

Not especially recommending this but it saved me several days of waiting to get the right shims. Like Hppants, I found most shims needed were in the 1.70 to 1.80 mm range so a kit with only a few of each size might not do it. If I could get the right shims locally without a wait, I would do so; especially if they were available in 0.025mm increments rather than 0.050mm which seem to be far more common.

If I was doing bikes other than my own, I would likely make up a kit with 5 shims each in the range of 1.65 to 1.85 in increments of 0.025. That's 45 shims and not worth it for me and my one FJR.

I only checked for shims with the local Yamaha guy. Might be worth checking with the Honda shop...

[N4HHE]

Isn't carbon buildup more likely on the exhaust valves than intake valves?

Crankcase ventilation includes oil vapor which can form deposits on the intake valves. Gasoline detergents are intended to remedy this situation. Dexos (and other newer spec) automotive motor oil formulations are also intended to address this issue. Some (such as Ford) were very proud to mass produce engines with direct injection. Have been forced of late to add conventional intake injection (my 2.7EB has both) due to deposits on intake valves from not having detergent gasoline to keep them clean. Reformulating the motor oil was not quite good enough.

[FJRoss]

Isn't carbon buildup more likely on the exhaust valves than intake valves?

Crankcase ventilation includes oil vapor which can form deposits on the intake valves. Gasoline detergents are intended to remedy this situation. Dexos (and other newer spec) automotive motor oil formulations are also intended to address this issue. Some (such as Ford) were very proud to mass produce engines with direct injection. Have been forced of late to add conventional intake injection (my 2.7EB has both) due to deposits on intake valves from not having detergent gasoline to keep them clean. Reformulating the motor oil was not quite good enough.

So you should expect more on intakes?
I always thought the opposite but I have limited direct experience - never had an engine apart that far!
My expectation was that the hotter exhaust valve would be more prone to "coking" oil and unburnt hydrocarbon residues.
Perhaps the exhaust valves get hot enough to allow the carbon to burn off?
I stand corrected!

[raYzerman]

Exhaust valves are hottest so carbon will tend not to accumulate there first. Intakes are rather cool with incoming fresh air and fuel. Three examples of carboned up.... my project FJR, FYB's brother's FJR, Festar's V-strom.... the latter two got fixed with a decarboning technique without tearing the engine apart. Subsequent valve shim changes necessary on more than one check, post-op, as clearances tightened with the valves seating better as they should. My project bike engine should never have been taken apart, and ended up with a newer engine. 90k on a bike I know was ridden like grandma, with regular treatments of RingFree.... take that baby up into the power band on occasion, won't hurt it one bit.
http://www.fjriders.com/forums/viewtopi ... t=forensic