Something horrible just have happened

[chiz]

So Randy correct me if wrong please. A compression test will indicate if the offending valve is closed? But with
.0880 gap between shim and cam lobe chances are that there is almost a 100% chance that the valve is a bit open.

      I know that there is a 275 shim in that bucket as of yesterday and in fact is the only shim that was not changed  for a different thickness.

     So I guess the question is what additional information will the test give me? or are you thinking that if the compression is good then the mystry is compounded?

                Chiz

[Country Joe]

Chiz,
Have you considered buying a cheap flexible bore scope that plugs into a cell phone? Crank that piston down to bottom and drop the bore scope down the spark plug hole. You will know in seconds if you have a bent valve....

Joe

[Pat Conlon]

Perhaps the valves are closed? A compression test would show this.

What are the symptoms? What caused you to open up the engine to check the clearances?

[Carson City Paul]

  Hi Chiz,
My name is Paul Lawson. I am an old school machinist. The problem or discrepancy you are seeing (.006) is because 3/32 is not .0880 it is .09375.

[chiz]

Perhaps the valves are closed? A compression test would show this.

What are the symptoms? What caused you to open up the engine to check the clearances?

No symptoms if you go back you will read it was a simple valve Clarence check and shim replacement except one valve ended up having a Clarence of .0880. I checked them because I had no idea when they were last done all of them needed tweaking except one. Randy said the before Clarence's were " horrible ".

[Millietant]

Chiz - have you read Paul's comment in his post above....

3/32 is not 0.0880 of an inch, it's 0.09375 of an inch........this could be adding to the confusion ?

[RPM - Robert]

Perhaps the valves are closed? A compression test would show this.

What are the symptoms? What caused you to open up the engine to check the clearances?

No symptoms if you go back you will read it was a simple valve Clarence check and shim replacement except one valve ended up having a Clarence of .0880. I checked them because I had no idea when they were last done all of them needed tweaking except one. Randy said the before Clarence's were " horrible ".

Here is what my dad said when he asked if .004 was okay: http://www.fjowners.com/index.php?topic=18962.msg192008#msg192008

[chiz]

Chiz - have you read Paul's

3/32 is not 0.0880 of an inch, it's 0.09375 of an inch........this could be adding to the confusion ?

  Negatory on that one a thou either side of my3/32 blurt has nothing to do with the operator induced issue
" me " . plain  reality is that the accuracy of this measurement is secondary question is why is it so great when it should be around .006

[chiz]

Perhaps the valves are closed? A compression test would show this.

What are the symptoms? What caused you to open up the engine to check the clearances?

No symptoms if you go back you will read it was a simple valve Clarence check and shim replacement except one valve ended up having a Clarence of .0880. I checked them because I had no idea when they were last done all of them needed tweaking except one. Randy said the before Clarence's were " horrible ".

     Actually the term was spot on acceptable and pointed out verbally how bad they were (exhaust side) in fact I welcomed the direct to the point comment.

Here is what my dad said when he asked if .004 was okay: http://www.fjowners.com/index.php?topic=18962.msg192008#msg192008

[chiz]

A week or so ago I busted my computer, FJ and snoblower. Man the blower would not stay running. Frustrated beyond belief I ripped the engine off and hauled the crank out of it.

    On the way I noticed the flywheel key had sheared off a real Ah ha moment. I am not ona small engine forum
  but my feeling is the answer to my problem probably would be long in coming.

  Likewise my kuck up to my bike In my opinion is supremly unique and I get the sense folks arenot clear at all on the issue mainly because of said rearity. A normal question like how do I take so and so apart would hav been answered many times

   But constant daily puzzling over the issue has led me to the conclusion that my cam is not bent..but the bucket is not coming up as high as the one right next to it this is why I am getting such a mind boggling clarence between lobe and shim... Sooo this is where I am  gent,s  Thaks for your time and thoughts.

        Chiz

[RPM - Robert]

There is no puzzle to solve here and this is not a rarity. If the bucket is not coming up as high as all of the others; there are two common causes in these motors.

1) The valve is bent <---------------------------------------------------------- Most likely since your problem is the intake side.
2) The valve seat fell out (Usually only occurs on the exhaust side)

If you tired the quarter trick and muffed up and the aluminum got gouged around the bucket. The bucket will now be dragging on the gouge until you take the bucket/valve spring out and clean up the bore. (This is not common as this is operator error)

So to make it easy.

• Did you use a quarter and did it shift and scrape the bucket bore?
  Yes, you may have gouged the bore and it may need to be cleaned up.
  No, go back to number 1
• Did you clean the bore up and is the bucket still sticking?
  Return to number 1

To fix, you will need to remove the head since the valve is stuck open. If you attempt the rope method, if the valve is not already bent, you will likely bend it. If at any point you turned the motor over with the bucket sticking and the valve was not bent already, it is likely bent now.

[Carson City Paul]

Chiz - have you read Paul's

3/32 is not 0.0880 of an inch, it's 0.09375 of an inch........this could be adding to the confusion ?

  Negatory on that one a thou either side of my3/32 blurt has nothing to do with the operator induced issue
" me " . plain  reality is that the accuracy of this measurement is secondary question is why is it so great when it should be around .006

Chiz... The difference between .09375 and .0880 is .00575. That would be 5 3/4 thousandths, 1/4 thou shy of .006 or 2 1/2 tenths of a thousandth less than .006
which would put you at the reading took on the other valve.