"J" Engine, Valve Clearances and Ticking Question

Ever since putting my J engine back together after having the head redone, I've had a ticking that was not there before. The bike has the APE manual cam chain tensioner which is spot on and doing it's job. It runs great and starts up with no trouble. Timing is correct, carbs are synced perfectly and there are no exhaust leaks and I've spent a lot of time making sure everything is perfect. But the ticking is loud. Loud at idle and through the RPM. Cold or Hot makes no difference. It's loud enough to be a bother and a concern.

Today I again checked the valve clearances and they are:

---

1

---

2

---

3

---

4

Exhaust

---

.012

---

.011

---

.008

---

.010


Intake

---

.009

---

.014

---

.008

---

.008


Spec clearances for this Engine are: .005 - .015


These clearances are very close to what I got after I put the top end back on in January.


My question is this:

Even though valve clearances are within spec, and yes a couple could be fine tuned, would the ticking be caused because there is somewhat of a swing between the clearances?

I'm running out of ideas. I know some ticking on certain bikes can be normal, but like I said, this is louder than I would expect.

What am I missing? Would the solution be to simply tighten up the clearances so they are more in line?

Thanks fellas.

they are kind of all over map,#2 intake is the first one id re shim .personally i run the exhuast valves looser than intakes to compensate for extra heat

You can use a length of hose, or a mechanics stethoscope to pinpoint the exact source of the sound.

Get a new set of feeler guages just to be sure, and make all your clearances around the .10 mark.

Be certain you are pressing the feeler guage flat against the shim before dragging it back and forth under the cam heel.

GL!

"Spec clearances for this Engine are: .005 - .015"
Is this (.005) correct?

KZ900 & Early 1000's @ .05mm... I get that but .00 5
up to .015... Whoa, interesting...

Learn something new everyday.... Cool!

OMR

I think we are having unit conversion misunderstandings, inches are bigger than millimeters...

Reason I asked.... Then all these measurements would be extremely tight thus little to no clearance, under the .05 specification....

Exhaust

---

.012

---

.011

---

.008

---

.010

Intake

---

.009

---

.014

---

.008

---

.008

Hopefully just a miss print...

OMR

well, assuming he did make them all way too tight, that wouldn't explain the ticking.

Are you sure that you don't have an exhaust leek?? Are the cams stock?

Maybe some conversion for the yankee folks... pretty well known for most part

.05mm roughly .002 inch
.10mm roughly .004 inch
.15mm roughly .006 inch
etc. etc. etc.

If his error is a typo in mm, then were ok.

If he is using inches, those clearances are WAY too large!

So... whats up! :laugh:

Inches... mm...

9am53 wrote:

well, assuming he did make them all way too tight, that wouldn't explain the ticking.

Correctomondo...

Way too tight would be dead silent, as he lost compression and his exhaust valves started to fry :blink:

They tick when the gap is too large only.

Peace!

Yeah, I'm smart enough to figure the conversion... :whistle:

.05mm - .15mm or .002 - .006 inch for spec...


Exhaust

---

.012

---

.011

---

.008

---

.010
Intake

---

.009

---

.014

---

.008

---

.008

Example:
.012" = .3048mm thus double the clearance gap spec.
.012mm = 0.0005" extremely tight clearance gap

.008" = .2032mm large out of spec clearance gap.
.008mm = .0003" tight clearance gap.

Either way you look at it, the numbers don't jive to spec.

As mentioned, too large ticky-ticky.... Possibly spit a shim pending which measurement system was used...

Too tight, not good on the valves...

OMR

9am53 wrote:

I think we are having unit conversion misunderstandings, inches are bigger than millimeters...

Yes these are the correct specs, I didn't copy them right.