Dumb Question #876 Valve Clearances

[Yogi]

Go easy!

Why do Ducati have two sets of measurements for valve clearances. I have a "Checking Clearance" and an "Adjusting Clearance"?
So  for my bike M1100
Intake Openers Adjusting Clearance 0.10 - 0.15mm and Checking Clearance 0.05 - 0.15mm.
Most other manufacturers just give you what the clearance is supposed to be hot or cold.

So which one do I set the bike too?

[SpikeC]

 I believe that the checking clearance is for checking the valve timing, and the adjusting clearance is for adjusting the running clearance.
I am not a professional mechanic and do not play one on TV!

[Speeddog]

My understanding is "adjusting clearances" are what they should be set to if they're checked and found to be outside the "checking clearance".

For air cooled 2-valvers, I set intake openers to 0.004", exhaust openers to 0.005", and all closers to be tight enough that a 0.002" feeler gauge won't fit and loose enough to not drag on the cam.

The plain bearing cams feel a little draggy just by themselves.

[Yogi]

Thank you guys. Food for thought there Spike....

[ducpainter]

I basically use the same numbers as Speeddog.

They should be set with a cold engine.

[SpikeC]

 As .1mm equals .004", I'd say that confirms my thinking.

[ducpainter]

As .1mm equals .004", I'd say that confirms my thinking.

Regarding cam timing clearance?

I always thought they used very close to zero for that.

[SpikeC]

 the .1mm is the adjusting clearance for running clearance, the .05mm is the checking clearance, which is pretty small.
I could tell that this would be open to a lot of misinterpretation!

[ducpainter]

the .1mm is the adjusting clearance for running clearance, the .05mm is the checking clearance, which is pretty small.
I could tell that this would be open to a lot of misinterpretation!

Agreed that .05mm or .002" is small, but it's the range of checking clearance that makes no sense for it to be used for valve/cam timing.

[SpikeC]

  I think it would be helpful to know the context of the OP's information here. The numbers do not make sense!

[Howie]

Pretty much standard in the industry is "checking clearance" means if it is in that range, it is acceptable and "adjusting (sometimes the term preferred is used) is the spec you use when adjusting.

[Speeddog]

Two pics from a service manual:

[Yogi]

Pretty much standard in the industry is "checking clearance" means if it is in that range, it is acceptable and "adjusting (sometimes the term preferred is used) is the spec you use when adjusting.

I'm intrigued I have never seen two sets of values as per Ducati in over twenty years of working in automotive, I have only seen one exception to this rule and that is some auto manufacturers will give you a Hot and a Cold setting. However this may not be the case on your side of the pond hence "Pretty much standard in the industry" (In Europe).
I don't see any relevance to having two sets of values. surely it would be adequate to just say the clearance should be between X - Y?

And then Speeddog  adds another couple of terms not in my workshop manual, Assembly and Control vs Adjusting and Checking.

Thanks for the info guys

[ducpainter]

I'm pretty sure the two sets of values coincide with  Ducati's 'relaxed' service intervals.

I don't think you saw the two sets of numbers in years past.

[Speeddog]

The pics are from a paper manual for M600/750, actual year unknown as for some strange reason Ducati saw fit to not put the year on the manual.

AFAIK, M600 was 1994-2001, M750 was 1996-2002.
So being totally literal, manual can be '96 to '01.

The allowance of closers up to 0.008" is really shocking, as they run quite crappy that way.