Same problem new question-valves

[DELL82]

Valve adjustment is driving me crazy Read a post the other day about where the peak of the lobe must be to take gap readings- perpendicular to shim and same angle as valve stem. Well I rotated engine until the above description was true and took a reading. Then I jogged the rotation, while sliding the feeler gage in and out. To my amazement the gage got looser and looser until the lobe was about 40 degrees off angle to the valve center line. The next valve was dead on inline with the valve stem. Which gap reading should I use? Several valves are at different angles to the center line when widest gap is read! My readings using the widest readings gotten are as follows.Exhaust #1 0.2, #2 0.2, #3 0.18, #4 0.215. Intake #1 0.14, #2 0.18, #3 0.15, #4 0.15. From perpendicular reading to widest reading there is as much as 0.03mm difference.

#2 intake shim was removed and was a 265 shim, what do I replace it with?
NOTE: Took spark plugs out then screwed back in two threads, very loose, let me rotate engine and no dirt or other debris can inter the chamber, worked well.
I have four shims to swap with anyone for the ones I need. (2)260's, (1)265. (1)280.

[mro]

Pretty sure your cam specs are the same as this.
Would check cam cap torque and then measure agin.
Can also measure cam with a micrometer and check below for specs. Would seems unusual for it to be out of round unless metal hardness was not uniform when made.



mro
btw
can use plastagauge to check cam "bearing" specification if cam measures good. (only a couple bucks at your local auto parts store)

[trbig]

Your intake #2 needs a 270 shim. By your readings, all your exhaust but one are out of spec, and it is just barely in. As your valves get worn, the readings will get smaller.. the valve will sink itself deeper into the seat and shrink the gap between the shim and the cam.

Tod

[HobbyMan]

You may be getting oil beneath the shim inside the bucket. If you have taken the shims out, make sure to run the crank through twice to make sure the cam pushes all of the oil out before you measure.

[DELL82]

Thanks guys. As usual there is a lot of support here and it is appreciated very much. I will check the cam dimensions tonight. HobbyMan I will check out the oil and remeasure all, remove all shims from exhaust side, document sizes. Will let you all know results and shims needed. Again THANKS
Dell82

[prometheus578]

Cams are rarely true all the way around. They don't have to be.
The gap you are measuring serves two purposes. One is to ensure there's a gap to compensate for the valve heating up and expanding(note how exhaust valves, since they get hotter, always have a larger gap than intake valves)
Secondly, to a smaller degree, valve clearances affect timing... in the way that a valve with a small clearance will open sooner than a valve with a wider gap.
To adjust properly(specifically for the heat expansion), you look for the point of smallest gap and adjust there. This is how our cams are designed.
On other cams, like some Kawasaki's, you set the gap with the intake and exhaust lobes facing away from each other(measuring the gap on the sides of the cam, not the portion opposite the lobe. If you'd set "their" clearances with the lobes pointing upward, when the cam comes around to the sides, there would be no clearance and the opening timing would be off.
Different cam designs fer different engines. Always follow the instructions designed for the machine.
The wider gap on the sides of our cams is meaningless and should be ignored. (the same goes for anything that HobbyMan writes... but in this instance, he is correct)

[Ken Talbot]

Originally posted by prometheus578

To adjust properly(specifically for the heat expansion), you look for the point of smallest gap and adjust there.

Prom - did you mean to say 'look for the point of largest gap'? Seems to me you would move the cam back and forth a bit to find the widest gap between camlobe and shim. You would then shim thicker or thinner as required to bring that gap to the desired spec.

[DELL82]

Hey! Now I am really confused How is that again guru's. What and how is the best way for me to take readings? Please let me know so I can proceed with work tonight.
DELL

[mro]

Cam lobe perpendicular to shim/bucket as first described.

Porn did answer the question regarding the "extra" clearance on side of cam. Learn something new here regularly...


mro

[DELL82]

Good, mro I will recheck the gaps tonight and readjust my figures. Then remove all shims to catalog their sizes and get back to youall for the correct sizes needed. Hopefully someone will help with swapping out the ones I need with the ones I have.
Dell

[trbig]

Porn did answer the question regarding the "extra" clearance on side

This is the exact opposite of the problem known as the John Holmes syndrome...

I'm glad that this stuff can answer some questions for you though MRO! lol..

Tod

[trbig]

And Dell...

Do you have a local shop? Sometimes they will swap with you. Lots of bikes use these shims, but be careful. These are 29mm shims, and there is a 29.5mm shim out there.

Tod

[prometheus578]

Prom - did you mean to say 'look for the point of largest gap'? Seems to me you would move the cam back and forth a bit to find the widest gap between camlobe and shim. You would then shim thicker or thinner as required to bring that gap to the desired spec.

No Ken, as I wrote, I meant the smallest gap.
Not all designs of cams are perfectly round(and I'm not talking about the lobe area)
Suppose the clearance (in the proper area) was already at .004. If there is an area of larger gap on the side of the cam, say .008, and you adjust THAT area to .004, when the true area comes around again it's clearance then would be zero or less... meaning it may be holding the valve open and would surely do so when the valve gets hot and expands.
Again, the moron of this story is... adjust the clearance with the cam in the position that the manual calls for.
And speaking of moron...

Porn did answer the question...

He may have spelled my name wrong, but at least it's still boldly capitolized out of respect and reverence. That's all that matters.

[Ken Talbot]

I follow what you're saying, but I'm having trouble knowing how you would know the cam wasn't actually supposed to be soming into contact to start opening the valve, or still be just easing it closed. By setting to a wider spec at a 'closer' spot on the lobe, woldn't you effectively be changing the duration?

[mro]

originally posted by Ken the Talbot
By setting to a wider spec at a 'closer' spot on the lobe, woldn't you effectively be changing the duration?

originally posted byProm
adjust the clearance with the cam in the position that the manual calls for

So if not adjusting according to spec's for that particular cam, guess you could be changing both timing and duration different than manufacturer designed.
______

soming into contact to start opening the valve

He may have spelled my name wrong

, the "n" and "m" are right next to each other and is conceivable that one could have inadvertently hit the wrong key.
"c" and "s" are on totally different rows


mro
that's not my XScuse, but that's my story