Valve adjustment | Page 2 | GTAMotorcycle.com

Valve adjustment

...and using paper to check valve lash is dumb. Paper is compressible.
and yet it has been done.
Some skill may be required to pull off anything that I indicate as being a bush fix :LOL:
 
and yet it has been done.
Some skill may be required to pull off anything that I indicate as being a bush fix :LOL:
It does have its upsides. If the paper rips, you were too tight. You can be way too tight with a metal feeler and still rip it through. I have never had issues on cars or bikes, lawnmowers on the other hand. Frig me. So little tension in those valve springs, setting lash is a nightmare.
 
On most motors you would find it almost impossible to distinguish the difference of plus or minus a thou or two, as long as you're in spec... even with a dyn
Then you would not be one to try and service a Honda powered Montesa.
Practice using a micrometer on your feeler gauges and see how tight it has to be like I keep saying :/ it works.
 
In shim-under-bucket applications that I've seen, there will be only two available shim thicknesses that will put the clearance within the allowable range. There's no "set it to 75%" or whatever. If the spec is 0.11 - 0.20 mm and the shim that's in there is a 1.65mm and it's a smidge too tight, you'll have a choice of using a 1.60mm to put it in the tight half of the allowable range or a 1.55mm to put it in the loose half of the adjustable range.

OEM shims come in 0.025mm increments, but you'll not find those in aftermarket shim kits that I've seen - they're all 0.05mm increments. Only way you have those is by luck if you've kept them from previous adjustments of an engine that happened to have those in it from the factory, and you happen to have one kicking around.
 
The tighter tolerance gives more lift. If you,ve ever adhjusted the valve on an old Z1 or KZ900 you can really appreciate what a pain the shim under bucket is. How often did those old Kwaks actually spit out the shims?
 
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Honda screw adjusters have a square head on the bolt that just happens to be the same size as a Robertson screw (the red one)
you can make a handy little valve adjuster tool with a short wood stick and a screw stuck in the end of it :geek:

... :LOL: definitely another bush fix:
valvetool.jpg
 
Quick question on valve adjustment !!!
the measurement seem to be within spec.
measured as follow
IN - Left (0.14 mm) Right (0.14 mm)
EX - Left (0.24 mm) Right (0.29 mm)

spec is
IN - 0.16 -+ 0.03 mm
EX - 0.27 -+ 0.03 mm

Should I swap the shim???

valve.jpg
 
Quick question on valve adjustment !!!
the measurement seem to be within spec.
measured as follow
IN - Left (0.14 mm) Right (0.14 mm)
EX - Left (0.24 mm) Right (0.29 mm)

spec is
IN - 0.16 -+ 0.03 mm
EX - 0.27 -+ 0.03 mm

Should I swap the shim???

View attachment 46796
See Brian's answer about four posts up
 
Quick question on valve adjustment !!!
the measurement seem to be within spec.
measured as follow
IN - Left (0.14 mm) Right (0.14 mm)
EX - Left (0.24 mm) Right (0.29 mm)

spec is
IN - 0.16 -+ 0.03 mm
EX - 0.27 -+ 0.03 mm

Should I swap the shim???

View attachment 46796
Looks ok normally clearances tighten not loosen I would leave it alone.

Sent from my moto g(8) plus using Tapatalk
 
I'll bet that is how it left the factory. Good to go.
 
Quick question on valve adjustment !!!
the measurement seem to be within spec.
measured as follow
IN - Left (0.14 mm) Right (0.14 mm)
EX - Left (0.24 mm) Right (0.29 mm)

spec is
IN - 0.16 -+ 0.03 mm
EX - 0.27 -+ 0.03 mm

Should I swap the shim???

No. You are within specifications right now.

You *could* put a shim 0.05mm thinner in both intake valves, but then you would be on the loose limit of specs instead of 0.01mm clear of the tight limit.

You *could* put a shim 0.05mm thinner on the left exhaust valve (currently at tight limit) and end up 0.01mm clear of the loose limit on that valve (same as where the right valve is now), and you *could* put a shim 0.05mm thicker on the right exhaust valve (currently at loose limit) and end up 0.01mm clear of the tight limit on that valve (same as where the left valve is now).

Or you could leave the darn thing alone, because it's fine the way it is.
 
No. You are within specifications right now.

You *could* put a shim 0.05mm thinner in both intake valves, but then you would be on the loose limit of specs instead of 0.01mm clear of the tight limit.

You *could* put a shim 0.05mm thinner on the left exhaust valve (currently at tight limit) and end up 0.01mm clear of the loose limit on that valve (same as where the right valve is now), and you *could* put a shim 0.05mm thicker on the right exhaust valve (currently at loose limit) and end up 0.01mm clear of the tight limit on that valve (same as where the left valve is now).

Or you could leave the darn thing alone, because it's fine the way it is.
Thank you :D

I was going leave everything the way it was and reinstall the valve cap couple days ago but figured I have never done this kind of work before and decided to go ahead and swap 2 x intake and 1 x exhaust to 0.05 thinner. It was easy on the cbr250 just pull the rockerarm pin. I was able to reuse 3 shims just need to buy 1 and put everything on the loose limit.

Everything was going so well til I dropped 1 shim :eek: . I was able to retrieve the shim with a little help from this magnetic pickup tool it wasnt easy i was ready to tear the engine apart to get it out lol. It's all done now overall it was fun and I learned alot and definitely cover all the holes/passages/nooks and crannies.
 
I think I'll just mention here that valves tighten with wear as they embed into the valve seat and your clearances become slightly reduced with time. The friction wear on the parts that move the valve are suppose to be almost insignificant unless you have a lubrication problem.
 
and yet it has been done.
Some skill may be required to pull off anything that I indicate as being a bush fix :LOL:
I've used paper to gap plugs, don't recall using it to check valves. Standard 20 copy paper is dependably .004, cigarette box paper .008 and a business card .01 (2.5x a sheet of copy paper).
 
And don't forget to greese your axel stiks!
 
And don't forget to greese your axel stiks!
:LOL: why, to stop the titanium from rusting?
way more important to tighten down all your pinch bolt thingies
 
:LOL: why, to stop the titanium from rusting?
way more important to tighten down all your pinch bolt thingies
You prolly don't know what i was referring to.Here,this will give you a good laugh.
 
Thank you :D

I was going leave everything the way it was and reinstall the valve cap couple days ago but figured I have never done this kind of work before and decided to go ahead and swap 2 x intake and 1 x exhaust to 0.05 thinner. It was easy on the cbr250 just pull the rockerarm pin. I was able to reuse 3 shims just need to buy 1 and put everything on the loose limit.

Everything was going so well til I dropped 1 shim :eek: . I was able to retrieve the shim with a little help from this magnetic pickup tool it wasnt easy i was ready to tear the engine apart to get it out lol. It's all done now overall it was fun and I learned alot and definitely cover all the holes/passages/nooks and crannies.
That's exactly what I would have done. Now all four valves are at the loose end of the specs and won't have to be touched again for a long time.
Once you've done all that work I don't see the point in not doing the needed adjustment.

Sent from my SM-A530W using Tapatalk
 
You prolly don't know what i was referring to.Here,this will give you a good laugh.
I liked this part better: " I've seen excavator arms being greased every morning by the operators "
Sometimes they even accidentally get some grease on the pins, bearings and bushings (y)
 

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