Tappet clearance & compression

[BigVic54]

Still huge! Should be .03 -.08 mm (.001" - .003")

Do you think that's enough to make the compression drop?

[8ball]

Did you mean .01? .1 mm would not cause your issue, but I am questioning what you are actually reading. If you mean .01 mm, most feeler gauges don't go down that small. It would be a special set.

If they are reading as large as .2 mm, you may have a bent valve

[BigVic54]

Did you mean .01? .1 mm would not cause your issue, but I am questioning what you are actually reading. If you mean .01 mm, most feeler gauges don't go down that small. It would be a special set.

If they are reading as large as .2 mm, you may have a bent valve

Prior to changing the shims the compression was good. After changing them it dropped. Nothing else was done. I don't see how it could be a bent valve. The gaps are anywhere from .07 to .15

[ddlaz]

0.15mm is fairly large, but not wildly crazy. Going up 2 sizes on a shim will fix that gap.
0.07mm is within spec.
Do a leakdown or makeshift leakdown with a compression tester.
Put the cylinder to TDC where the valves are all closed.
screw in your compression tester hose into the spark plug hole, attach an air hose with low air pressure(~45psi?)
Listen for air leaking/hissing.
If you hear a significant amount of air leaking, chances are, your valves are bent.

[londonboards]

I made the Rookie mistake last week of using an Imperial feeler gauge to measure metric gaps. All my tappets ended up being around .23 mm when I used the 10 thou feeler gauge. Instead of their proper measurement between .08 mm and .13 mm. This was on a GS1150ES with adjustable screw tappets (16 of them!) but it wasn't too much of a pain to do it all again - except for having to take all the fairing off.

[Steve]

I made the Rookie mistake last week of using an Imperial feeler gauge to measure metric gaps. ...

No problem using Imperial feelers, I do it all the time.

You just have to be sure which numbers you are reading.

.

[ddlaz]

No problem using Imperial feelers, I do it all the time.

You just have to be sure which numbers you are reading.

.

Thankfully my set has both listed on the feeler gauge. The only problem is that they only step up in imperial units at 1 thou intervals. Good enough to get you within the ranges though.

[tkent02]

If you went from having compression to having none, it ain't the gauges.

[BigVic54]

If you went from having compression to having none, it ain't the gauges.

Could it be that the gaps were too large?

[ddlaz]

Too large of gaps would not show zero compression. In the worst case scenario of gaps being so large that the cam lobes don't touch the shim/bucket/valve train, the valves wouldn't open and no air would get in other than through small leaks at the valve seals or compression tester. With the little air, it already had in the cylinder prior to sealing, it'd have SOME compression.

Anyhow, the only way to get that large of a gap would be if the valve was stuck open all the way.


Question - how are you getting the bucket compressed for removing shims? the suzuki tool or zip tie method? I have a fear that maybe you opened a valve with the piston at tdc. The valve was opened on the piston top and bent....

Leakdown will tell you the reason why you have zero compression.

[Steve]

Question - how are you getting the bucket compressed for removing shims? the suzuki tool or zip tie method?

We have also had NO confirmation on the method used to check clearances.
Were the cam lobes in the correct positions?

.

[limeex2]

Could they be so tight that the valve never fully closes?

[BigVic54]

We have also had NO confirmation on the method used to check clearances.
Were the cam lobes in the correct positions?

.

I believe the cams were in the incorrect positions when I checked the clearances. I have checked them again the correct way, I hope, and have ordered new shims. I'll get back to you after I install them.

[ddlaz]

No offense but do you mind sharing your clearance numbers and their shim sizes so we can help you better? I'd hate to have you wait just to find out that they weren't enough.

[BigVic54]

Question - how are you getting the bucket compressed for removing shims? the suzuki tool or zip tie method? I have a fear that maybe you opened a valve with the piston at tdc. The valve was opened on the piston top and bent....

Leakdown will tell you the reason why you have zero compression.

You're thought is that depressing the tappet to remove the shim bent the valve? Wouldn't that take a significant amount of pressure? I used the Motion Pro tool to hold the tappet down and never pushed that hard.