checking valve clearances

[breahn riley]

I've gone through all the topics and seen none on how to check valve clearences. I've seen A LOT of people asking the same questions so I made sure I couldn't find the answer before this post. So checking valve clearances. I'm assuming this is the distance between the top of the valve stem and the bottom of the rocker? I know its diffrent from the intake to exhaust side. So at tdc do I just adjust the rockers to the apropriate feeler gauge? Also my bike is an 81, I know the specs are diffrent through years. I'm not sure what motor mine is? Like the XS1 or XS2. I forget what the haynes manual said.

 

[xsjohn]

The later models call for .0025 thou on the intakes.......although at that setting they are quiet but I found it takes out the valve tips from lack of lubrication.......better to set them at a simi snug .004 and the exhaust at .006..........

xsjohn

 

[jayel]

yes piston up to TDC on compression stroke, both rocker arms should be loose (valves closed) then a slight drag on feeler gauge blade when adjuster nut is locked down

 

[breahn riley]

How do I tell when the compression stroke is occuring? And both rocker arms? Aren't there 4 rocker arms? And when it's tdc on the compression stroke won't all four rocker arms be able to lift up and down a little bit?

 

[gggGary]

You do the cylinder with both rocker arms loose turn the crankshaft 360 then the other cylinder will have it's two rocker arms loose (TDC compression stroke)

 

[urbandork]

if u rotate the motor and put ur thum over the spark plug hole u should be able to feel for the compression stroke on that particular cylinder.

 

[breahn riley]

Like ill feel air comin out? Also, is there a trick to keepin the bolt tight on top of the rocker arm? Or do you just rely on gettin the bolt tight with a wrench?

 

[jayel]

when you bring it up to TDC the rockers on one side will have some play in them the other side will be definatly tight (on the cam lobe) tightening the tappet, well it helps if you have four hands like all us great mechanics, one to hold that special 4mm tappet wrench, one for the wrench to tighten the lockdown nut and one to hold/slide the gauge blade, the free hand can be used for what ever else needs doing

 

[breahn riley]

So I bought a feeler gauge set and the smallest size was .006. Where do I get .004? I can't believe there is one thinner than .006, its as thin as paper!!

 

[Gordon]

Actually breahn,most paper is about .004". Advance Auto parts has them, inexpensive, too.

 

[breahn riley]

Cool, I'm gunna go with paper then. Parts store is closed and I wanna get the motor back together and bolted back into the frame for mock up.

 

[Travis]

I don't think that's really going to work out that well for you. There is no problem with checking valve clearances with the motor in the frame, unless you have some crazy custom frame that blocks the valve inspection covers. Just do it later when you get the proper gauge.

 

[tx650]

Hi there,a bike that is 29 years old will more than likely have mileage on the clock and that means wear and tear.....Unless work has been done of course.
If work has been done in the top end (head) like new valves/rocker arms and cam then it might just be a simple case of valve adjustment.TDC piston at top, lobes pointing down.
The areas of wear to look for are the tip of the valve stem as after a while an indent will be made after years of contact therefore making a correct adjustment impossible.
Another one is the rocker arms where they contact the cam,this could be worn and even possibly the cam itself.
Then there are the tips on the other end.
The best thing to do when the engine is apart don't skimp on parts,use the best you can get and do the job right the first time.This can make the difference between long and enjoyable rides on the best bike that has ever came out of Japan or trailering it.
I was doing up one of my bikes and after adjusting the valves and with the bike running a bit crappy I was told to inspect the tops of my valve stems and guess what???
Valve adjustments are made when the engine is cold so best to leave it overnight.

 

[gggGary]

Is it possible you got a METRIC feeler gauge set?
for the XS650 From Mikes XS tech tips.

16. Q. What valve tappet clearance do I use ?
A. All Models 1974-84: Inlet: 0.003 inches (0.075mm.)
Exhaust: 0.006 inches (0.15mm.)
A. All Models 1970-73: Inlet: 0.006 inches (0.15mm.)
Exhaust: 0.012 inches (0.30mm.)
Note: Set valve clearance with cylinder being worked on at top dead center on compression stroke.

 

[jayel]

Cool, I'm gunna go with paper then. Parts store is closed and I wanna get the motor back together and bolted back into the frame for mock up.

the problem with paper is it will squeeze down, giving a false reading, the slight drag on the metal gauge you want would also tear paper

 

[breahn riley]

I had the head apart already. I thought the top of the stems looked fine, no real pitting or anything like that. The motor only has 12k on it. So hopefully the damage that I'm not seeing is minimal. Ill be picking up the correct gauge when I get a chance. Its nuts to think the differnce between .004 and say .006 would make a big difference in the way the motor preforms!!

 

[XSLeo]

It can effect the way an engine runs, but the amount of noise is more noticable.

 

[yamaman]

Of course in this case, noise being prefered to silent!
Loud valves save lives!

 

[5twins]

The top of the stems isn't where the damage usually 1st shows, it's on the bottom of the adjuster screws. Pull the screws and look at the bottoms. They'll come right out with the engine all assembled. Not much can be done about this. I think it's a poor design. Replace the screws and the same thing will eventually happen to the new ones. The only sure cure is different style screws like the VW "Elephant's Foot" type.

 

[restforyoursouls]

I just got a '73 TX650. I've read different numbers in different places for what my valve clearances should be set at.

One site said that my bike should be Intake: .003" Exhaust: .006" for '73. Mike's XS says that '73 and earlier clearances should be Intake: .006" Exhaust: .012".

The Clymer I have for 70-74 XS650's was way off with Intake: .005" Exhaust: .003"

My question is......WHICH IS CORRECT? This will be the third time I've done it in three days if I have to change it again so I should be getting pretty good at it

Thanks in advance,
-Daniel