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SL500 valve adjustment - Help needed
http://ducatittandf1.com/viewtopic.php?f=25&t=11501
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Author:  Desmo Tutu [ Mon Jan 30, 2017 6:12 pm ]
Post subject:  SL500 valve adjustment - Help needed

I post this in the Pantah Hot Rod section, since I have a -87 F1B fitted with an SL500/600 engine. (engine # is SL500xxxxx, but it figures as a 600 in the registration papers)

I am in the middle of a small job to make in ready for the coming season. Have only ridden it a short trip a couple of years ago before it was put aside. In Norway we have a 30-year rule where I now can registrer it as a veteran bike with very low tax and insurance. So its time to dust of and ride... :)

It was running OK the last time. Not great, but OK...
The plan is to fit new belts etc. So I took of the valve covers and did a check on the valve clearance.

Measured at the opener:
Rear/vertical cylinder
Int. 0,05mm
Ex. 0,15mm

Front/Horizontal cylinder
Int. 0,10mm
Ex. 0,10mm

If i'm lucky maybe I can switch the shims on the rear cylinder to get 0,10 on both valves?

The "problem" is the closer and valve collet. I can't measure any gap here, and are not able to turn the collet unless I twist really hard (with my fingers, no tools)
Not able to push the closer down, its 0,00 tolerance.
Shouldn't there be some free movement here?

The SL dont't have the clip on the opener axel, so I guess I have to take out the opener axel and remove the opener to get access to the collar.
How easy should it be to twist the camshaft with the valve system intact. I have a "feeling" that maybe its is binding in some spots, but don't now if this is correct or not.

My first attempt at checking and adjusting desmo valves, so I appreciate any tips and trix :)

Author:  Wolf [ Tue Jan 31, 2017 10:41 am ]
Post subject:  Re: SL500 valve adjustment - Help needed

Dear Tutu,

to get a feeling, wether or not the closer is correctly shimmed you have to overcome the spring load of the closer rocker. Press gently with a screwdriver on the closer rocker - than you should be able to turn the collet without much resistence.

In case the desmo head is correctly shimmed, you should be able to turn the camshaft without remarkable resistance, binding spots shall not be noticeable.

The likelyhood of just swapping the opener shims is not very high, but who knows :-)

Happy shimming!

Wolf

Author:  Desmo Tutu [ Tue Jan 31, 2017 5:32 pm ]
Post subject:  Re: SL500 valve adjustment - Help needed

Hi Wolf

Thanks for the input. The problem is when I try to press down the closer with a screwdriver, there are zero movement. So I suspect the closer are pressing the valve against the seat with to high pressure.

Roy

Author:  brad black [ Wed Feb 01, 2017 3:34 am ]
Post subject:  Re: SL500 valve adjustment - Help needed

remove the opening rockers and timing belts so you can feel if there is any drag on the cam.

Author:  ducadini [ Wed Feb 01, 2017 5:41 am ]
Post subject:  Re: SL500 valve adjustment - Help needed

Hey Tutu,
There are tools to measure in increments of 0.01 mm (0.05 to 0.15 mm) think it was a SKF tool.
This way You are more accurate because it seems very strange that the free play is 0.05 0.10 and 0.15.
The chances of switching the two shims and having both valves correct are the same as finding a F1 hidden in a barn. Could happen but don't hold your breath.
Take of the belts, make sure valves on both heads are closed, and turn the crank untill one piston is down.
Lube the cam and rockers lightly.
Now You can turn the cam without touching anything and feeling if it's turning over without binding, checking the play on ALL the rockers (there should always be play at or the opening or the closing rocker).
You should be able to turn it easily yet feel it when you open a valve.

ciao
ducadini

Author:  Carlo [ Wed Feb 01, 2017 7:43 am ]
Post subject:  Re: SL500 valve adjustment - Help needed

I do not know if I understand the question, my English is shit, but what I wanted to say is that the opening of the valve can also be measured with a feeler gauge, but the closure is not measurable, but only palpable, it is a feeling , is a heavenly touch, it's like touching your ass to a nice girl ..... a great job .... :shock: :shock: :lol:

Author:  Wolf [ Wed Feb 01, 2017 10:09 am ]
Post subject:  Re: SL500 valve adjustment - Help needed

Wow - Carlo,

these is a complete new perspective of working with desmo heads, now I like it even more!

grazie mille!

Wolf

Author:  Carlo [ Wed Feb 01, 2017 2:43 pm ]
Post subject:  Re: SL500 valve adjustment - Help needed

:lol: :lol: :lol:maybe I let myself go a little too ...
Wolf wrote:
Wow - Carlo,

these is a complete new perspective of working with desmo heads, now I like it even more!

grazie mille!

Wolf

Author:  ducadini [ Fri Feb 03, 2017 2:28 pm ]
Post subject:  Re: SL500 valve adjustment - Help needed

Carlo wrote:
it is a feeling , is a heavenly touch, it's like touching your ass to a nice girl ..... a great job .... :shock: :shock: :lol:


Yes indeed Carlo, but just like touching your ass to a nice girl : the consequences of doing it the wrong way could cost a lot of money ;)

Better to call it : fingerspitzengefühl (feeling it with the tips of your fingers)
This can't be misinterpreted and still says it all.

ciao
ducadini

Author:  Carlo [ Fri Feb 03, 2017 5:05 pm ]
Post subject:  Re: SL500 valve adjustment - Help needed

ducadini wrote:
Carlo wrote:
it is a feeling , is a heavenly touch, it's like touching your ass to a nice girl ..... a great job .... :shock: :shock: :lol:


Yes indeed Carlo, but just like touching your ass to a nice girl : the consequences of doing it the wrong way could cost a lot of money ;)

Better to call it : fingerspitzengefühl (feeling it with the tips of your fingers)
This can't be misinterpreted and still says it all.

ciao
ducadini


good job :lol: :lol:

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