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Valve check


jeravoy

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8 hours ago, skipperT said:

One other thought just occurred to me @dazzler24...

Sometimes it’s not always about the exact number when setting valves. Sometimes it’s about how the feeler gauge DRAGS when it’s inserted or withdrawn (yeah, yeah I know how it sounds). 

If we accept the 0.26mm number as listed, you could use your 0.25mm feeler gauge as a “tell”.  If it has some drag but feels loose especially when moved side to side, as opposed to straight at the lobe- then you can evaluate the actual clearance you’re measuring. Call it a “loose 0.25”. Then if a .272mm won’t fit or is quite snug and a .227 has no drag at all then that will indicate to you your actual clearance measurement. 

The biggest mistake I think people make is stuffing a larger feeler gauge in between the cam lobe and the tappet and saying “oh yeah it’s in spec” when in fact they’ve pushed to strongly with a stiff enough feeler gauge to compress the tappet/valve spring. That’s not an accurate way to measure the valve lash. Smaller sizes bend more easily so it’s harder to do that with say, a 0.04” (0.10mm IIRC?) gauge because it bends too easily. On our CP3 engines it’s even more important to be aware of and not force the feeler gauges into the exhaust cam clearances because of the tendency for these engines to “go tight” as they wear.

Developing that “feel” makes sense for anyone that’s adjusted screw/locknut type valve trains. But for someone who’s doing this for the first time on a shim-under-bucket design engine, there exists that possibility to not measure the clearances accurately. 

(I hope some of this makes sense.)

-Skip 

Well put skip, and that does make sense to me.  This note will go into my own notes of 'how tos' for when the time comes.

Thanks. 👍

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On 8/5/2017 at 10:22 PM, ilanr1 said:

Hi , just want to notice that there are 2 signs on the crankshaft.
The first looks like - and the second looks like < .
The first is for TDC = checking clearance, the second is for installing the cams = timing issue. 

I wish I had known that before I removed the camshaft caps. I picked the only mark that I saw, and it was the wrong one. I have the FSM and it didn't mention the two different marks during the removal procedure, nor the marks on the camshafts. I had to read through the install procedure to pick up on that. I wish I had started there.

I am in the middle of the job, and now I have to rotate the crank to the "<" position and align the camshafts to the marks on the caps. As long as I get those three marks right, will it be correct? DId I miss anything else?

2015 red FJ-09: Cal Sci screen, Sargent seat, ECU flash, slider combo, cruise, Rizoma bars, Matts forks, JRi shock, slipper clutch

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I think the FSM mentions it under “removing camshafts” not under “checking the valve clearances.”

water over the damn, so to speak at this point. 

to your question, as long as the crank is rotated to the correct mark, and the camshaft caps are in the correct position, and the marks on the cams line up with the tensioner installed and everything bolted down and tightened to spec…. Then yes, you should be good to go. 
After assembly, rotate the engine slowly in the correct direction 1 or 2 rotations and double check that your marks are still good and the cam chain didn’t jump on the sprockets or anything like that. 
Check you clearances again and make sure you have them where you want, then button it up. 
No adhesive needed on the valve cover gasket btw…

oh and beer… must have beer after.  

-Skip
 

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49 minutes ago, skipperT said:

oh and beer… must have beer after. 

I have found that before, during AND after has worked for me too.  Tends to steady the hand and improve the confidence.  The only potential downside is that the eyes can be prone to go out of calibration for those valve clearance checks.  😅

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4 hours ago, dazzler24 said:

I have found that before, during AND after has worked for me too.  Tends to steady the hand and improve the confidence.  The only potential downside is that the eyes can be prone to go out of calibration for those valve clearance checks.  😅

No brewskis for me while performing any precision work or that takes any significant brain power.  #1 I'd doze off and #2 I have precious little of the latter to begin with.  🥱

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3 minutes ago, PhotoAl said:

When putting the cam cover gasket in place I sprayed it with some spray tack that held it in place in the came cover while maneuvering the cover into place.  

Stange, on my 55,000 mile 15 on which I've had the valve cover off 4 or 5 times, it's stayed adhered and not even seeped (knock on plastic).  I always have just lowered the radiator without disconnecting any hoses and removed then reinstalled the cover from the front.  I can see possibly knocking the gasket loose though.

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you guys replace the valve cover gasket every time?  I know on my Triumph I had to or it would leak pretty well.  I have one on order from partzilla for my valve adjustment coming up.  But was just curious.

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Relating to the two marks on the crank. I almost made the same mistake. The book is clear, but it isn’t written for the home tech, it is written for a much more knowledgeable mechanic. I saw the two marks but assumed they were the same, since they look similar on the written page. I was fortunate to find a video somewhere that mentioned this. Even knowing there is a second mark, it is darned hard to find it thru that tiny portal down at that low place. You go past it so fast and must go all the way around again if you miss it. 

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A straw marked at TDC makes it easy along with a small flashlight 

It's not rocket science but a basic understanding of 4 stroke engines is essential. 

Now taking out a cam is more complicated than a twin or even a 4 in a way.

But the architecture is near identical for shim under bucket

The newer lighter finger follower lash system look different but still accomplishes the same functions.

 

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