Valve clearance.

[paso144]

Hello,

Since my Paso has reached the 30.000 km I thought of checking the valve clearance. So I started with the standing cylinder. With the piston in top dead center I measure a clearance of 0.05 mm on the opener on the exhaust side and 0.1 mm on the closer, which is within spec.

But on the intake side I don't measure a clearance at all. A 0.05 mm feeler gauge can't be put between the cup and the opener. The closer has about 0.05 clearance. Now I know that Ducati specifies the opener clearance at < 0.1 mm but I find it strange that there is no clearance at all. Has anyone of you ever encountered this?

The thought of a worn out valve seat crossed my mind but then I would also have measured a lot more clearance on the closer. I guess that no clearance/play can't hurt but I like to double check.

greetz Remko (Paso144)

[Tamburinifan]

Usually all clearances get wider.

a clearance of 0.05 mm on the opener on the exhaust side and 0.1 mm on the closer, which is within spec.

Not correct.
0.00-0,02 on closing, 0,10mm inlet/exhaust opening are the old specs.

[paso144]

Hello Gert,

0,00 to 0,02 mm looks like a strange value. How are you going to measure this when the measuring tool (feeler gauge) only has a resolution of 0,05 mm. Aren't you mistaking wiht inch values?

regards Remko

[Desmo_Demon]

I set my openers between 0.004" and 0.006" (0.10mm and 0.15mm)
I set my closers between 0.000" and 0.002" (0.00mm and 0.05mm)

To get the closers right, I make sure that I can not get the 0.002" (0.05mm) feeler gauge to fit between the opening rocker and opening shim. Then, to make sure that I do not have the clearance at a negative value, I push the closing rocker down (to relieve the pressure of the rocker spring), and make sure I can rotate the closing shim with my fingers. I also will remove the belt from the cam and rotate the cam while feeling for resistance or any sign of binding. If you cannot rotate the closing shim with your fingers and feel a scraping or resistance in the cam shaft when rotating, DO NOT leave the closing shim like this, as you are binding the system.

I hope this helps.

[Tamburinifan]

+1 on what dd says.
You should be able to turn the closing shim one half turn when spring is pressed down.

[paso144]

Ok,

So this is a lot of advice on the closer, although I don't understand the comment about a half rotation of the cup (tamburinifan?). But I'm still wondering wether a 0 clearance on the opener is a problem? And do you really think I need to adjust the clearance on the closer on the exhaust side which is currently 0.09 - 0.10 mm, because this is some work since you have to remove the opener by removing its shaft?

Regards Remko

[Skins]

I'd like to add that it is very important that all measurements are made with an absolutely cold motor, one that has been allowed to cool at least overnight, otherwise you will not get correct measurements.

Also, removing the rocker shaft is very easy - it takes only a few minutes to do.

[Desmo_Demon]

So this is a lot of advice on the closer, although I don't understand the comment about a half rotation of the cup (tamburinifan?).

As long as you are able to rotate the closing shim, you should be fine. At least half a rotation, in theory, would mean that the shim itself is nice and level on all sides and not machined at an angle, which could possibly cause binding.

But I'm still wondering wether a 0 clearance on the opener is a problem?

Yes, it is a problem because if it is not really zero, but negative, then this would mean that the valve is staying open when it should be closed. This can cause the bike to backfire through the carb(s), run hot, and possibly burn a valve.

And do you really think I need to adjust the clearance on the closer on the exhaust side which is currently 0.09 - 0.10 mm, because this is some work since you have to remove the opener by removing its shaft?

It may be "ok", but I wouldn't leave it like that. There are some people that say to adjust all shims to allow 0.10 mm of clearance, but.....I'm not one of them.

[Finnpaso]

I'd like to add that it is very important that all measurements are made with an absolutely cold motor, one that has been allowed to cool at least overnight, otherwise you will not get correct measurements.

Thats right, but very many forget to drive engine VERY HARDLY BEFORE valve adjustment !!! And if so, then there are normally plenty of shit around valve area and again totally wrong measurements.. I have noticed that many times and some really "ducati gurus" have told to me just same thing.... before valve adjustment, engine MUST BE AS CLEAN, as possible ! One Ducati maintainer here ask from customer, how he/she have ridden bike just? If answer is "normally" with quite low rpms, then he say, that come back again after some times, when you have ridden it with high rpms for long time !!!!! that is "reality"....

[paso144]

Thanks for all your reply's,

To start the cup under the opener which I can't measure because of lack of thinner feeler gauges then 0.05 mm, still can be rotated fully. So I would say there is some clearance probably in the region of 0.01 to 0.02 mm. So I don't sink I have negative clearance. But can anyone exactly state wan't the present values then have to be for opening and closing clearance.

regards,

Remko

[Skins]

My official Ducati Workshop Manual says opening clearance 0.1mm and closing clearance 0 to 0.02mm and that's what I do.

And Antti, as as ex-English language teacher, I must give you a lesson (although I do think you use the English language in a wonderful way): in English, "hardly" means "not much", as in 'I hardly speak any French, only enough to say oui and merci'; and "hard" means "strong" or "with great force" as in 'steel is hard' or 'Stoner rides his Ducati hard'.

[Tamburinifan]

But can anyone exactly state wan't the present values then have to be for opening and closing clearance.

Old specs as I stated above. They are from 907 ws manual. And recommended from experienced Duc shops on all
600-750-900 2V.
Late 90`s specs are 0,03-0,05mm closers in & out, 0,10-0,12 opening inlet, 0,12-0,15 on opening exhaust.

[Finnpaso]

And Antti, as as ex-English language teacher, I must give you a lesson (although I do think you use the English language in a wonderful way): in English, "hardly" means "not much", as in 'I hardly speak any French, only enough to say oui and merci'; and "hard" means "strong" or "with great force" as in 'steel is hard' or 'Stoner rides his Ducati hard'.

Skins, You are totally right !!!!! I did mistake with that "hardly/hard", but i hope, that You undestood my very bad english anyway I mix too much Fin and Eng grammar and i should go to school again.... Also need to read and learn more words, what is biggest problem and thats why my english is very "simple".... U dont know, how difficult its sometimes to read "usa english", cause they use sooo much very strange words and they shorten words, when they write something...... Anyway, its very good, that i have here now "personal trainer", Skins! U should correct me allways, when i do mistakes, cause i dont have time for school, cause all my time goes with my Ducatis.....

btw, that hard/hardly came just, when i mixed Fin and Eng too much, my mistake! Sorry.

[Skins]

No problem, Antti. Your English is really very good, you make very few big mistakes, and the way you use the language has a lot of "character" - you are a real asset to this site. I had to correct you because you often talk about 'hardly' riding a Ducati, which means means riding them only a little, but it seems you do exactly the opposite - you ride them a lot, you ride them hard (like me)!

All the best, mate!

[Finnpaso]

Thanks, Skins! It was just right, that You correct me and i am happy about that...