intake valve clearance

[1034am]

Everyone talks about opening up their exhaust valve clearance to .1mm and more, what's the thought on the intake side? Same?
Any risks?

[twocool]

Use suzuki spec. on intake...

Remember...if the clearance is small (between cam and valve shim) that the valve will open wider and stay open longer...

the concern with the exhaust valves, is the if the clearance is too small, or not at all...that the valve will stay open too long, or stay completely open...

Exhaust gases are real hot...The exhaust valves cool themselves when they are closed by conducting heat from the valve into the head...  If they are in contact with the head for too short of a time...the heat has nowhere to go...builds up, and can lead to "burnt" valves...Burnt means melted, or cracked..

Intake valves get nicely cooled by the gas / air mixture.  Also, intake valve is closed during the exhaust stroke...so not a whole lot of heat build up in intake valves..Using Suzuki spec, means that the valve opens nice and wide and you get a good flow if intake mixture into the cylinder..

More food for thought...

I don't think most riders actually check and adjust their valves as often as Suzuki recommends...It's  a PITA job...takes time, and you have to take apart a lot of crap on the engine...

So when you adjust the clearances...you are concerned with what the clearances are NOW...and also what the clearances are going to be by the next time you check them...

For me, that's once a year...about 10,000 miles....(I think Suzuki says check every 4500 miles)

Exhaust valve clearances get tighter with wear...so if your on the tight side now....you're gonna be too tight in 10,000 miles...

If you go a bit wider on the clearance now...you're gonna still be in spec in 10,000 miles from now....

Cookie

Everyone talks about opening up their exhaust valve clearance to .1mm and more, what's the thought on the intake side? Same?
Any risks?

[damo2211]

I have done mine twice since owning the bike, the exhausts I have opened up to 0.1 - 0.12 but the exhausts I have left to factory spec mainly on the high side 0.08.
I read a lot of posts about the subject before doing the job ans pretty much how twocool explained it.

[1034am]

was always wondering why nobody mentioned the intakes.... thanks for the help guys! 

[The Buddha]

Intakes on Kawasaki's and on most vehicles wear into the head a lot more/faster.
However that is less common on old school air cooled Suzuki's.

I have a oversized set on the MZ (5 valve) and my mechanic noticed that they were nearly intact when we opened it up last year.
That was shortly before he noticed that they were exhaust valve like (5 valve yamaha's can use 5 identical valves, 3 for intake and 2 for exhaust) ...

My thought was that they make intakes out of crappier material, since they tend to run a wee bit cooler. Yea to save 3c the manufacturers decided to put a crappy part in the depths of the engine. Great Idea, dumba$$es.

Cool.
Buddha.

[1034am]

Sometimes when i measure, i get different results. Is that indicate a sticking bucket? (I'm lining up the rt mark and the cam notches exactly the same.)
Is there a procedure, like, measure then rotate engine and confirm?

thx.

[The Buddha]

Sticking bucket - maybe - though its very unlikely to stick that high up. You pulling the shim to measure ? Then you could have oil float.

If it is not - you may have a slight uneven wear on bucket, cam etc, not a worry, the thing gets coated with oil and you don't have much wear anyway. It should sorta stay between the unevenness - like it shouldn't increase between checks. Unless you change shims. I had a crows foot pattern on 1 cam. I watched it for 50k miles, it barely changed, slowly got fainter. But essentially unchanged.

Cool.
Buddha.

[twocool]

Make sure to turn the engine a couple time around ..in the direction it runs...stop at the mark...do not go past the mark and back up..

You'll surely get a different reading if you go backward!


Cookie

Sometimes when i measure, i get different results. Is that indicate a sticking bucket? (I'm lining up the rt mark and the cam notches exactly the same.)
Is there a procedure, like, measure then rotate engine and confirm?

thx.