setting the timing

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Per Garbos
Diana
Posts: 55
Joined: Sat Feb 03, 2007 11:41 am
Location: Denmark

setting the timing

Post by Per Garbos »

I have the original Electronic ignition system at my 250 Desmo and would try to set the timing with a stroboscope.

But i am not sure where to find the marks,
There are som at the clutch cover - a line and a dot but nothing at the crankshaft - at least as far as i can see.

Do i need some special tool or are there some other ways.

Per
bobnorton
860 GT / GTS
Posts: 279
Joined: Wed Jan 16, 2008 2:18 am
Location: bromley kent

Post by bobnorton »

Hi Per, You will need a pointer to fit to your crank end on the drive side ,i think the outer case is marked, Classic Ducati (Jones?) has pointers.These lock into the notch in the end of the crank after you take the plug out.I'm not familiar with desmos.
Per Garbos
Diana
Posts: 55
Joined: Sat Feb 03, 2007 11:41 am
Location: Denmark

Post by Per Garbos »

Thanks, just been looking at Classic Ducati webside and i will contact Jones tomorrow. The tool is not that expencive so i will go for that.

Best Regards Per
bobnorton
860 GT / GTS
Posts: 279
Joined: Wed Jan 16, 2008 2:18 am
Location: bromley kent

Post by bobnorton »

HI Per, I don't know what the advance range on you motor is but on my old 250 i just set the static timing to give me the most kickback i can stand and its still not advanced as much as the motor needs for max performance!! Crude yes but i actually want to ride and be able to restart on the road, I must be a bit odd as no one else rides the things regularly.
Per Garbos
Diana
Posts: 55
Joined: Sat Feb 03, 2007 11:41 am
Location: Denmark

Post by Per Garbos »

Thats sounds heavy. - my 250 is heavy to kick over but i dont have the feeling that it will kick back.

Static is 5-8 degrees and advanced it is 36 -38 according to the manual.

Best regards Per
bobnorton
860 GT / GTS
Posts: 279
Joined: Wed Jan 16, 2008 2:18 am
Location: bromley kent

Post by bobnorton »

Hi Per, At any more than 5 degrees static starting becomes unreliable on my 250, I dont think my AAU gives the specified advance either, perhaps a couple of degrees less,so full advance is not really enough,I dont recommend kicking against the compression,bad for gears and stand. Best to ease past compression before kicking.Widecase has better gears and stand.My bike is faster with 10 degrees static but a pig to start and will stall too easily. Thats no good i need to ride!!.
Per Garbos
Diana
Posts: 55
Joined: Sat Feb 03, 2007 11:41 am
Location: Denmark

Post by Per Garbos »

I agree about the kickstarter problem - even the widecase is stronger.
Problem with desmo is that a valvelifter is not an option.
But i think that some of the non desmo had valvelifter.

BR Per
maelstrom
Cucciolo - the Lil Pup
Posts: 13
Joined: Thu Sep 08, 2011 2:42 am

Post by maelstrom »

Not exactly on topic however.
Static timing.
There is a dot on your ignition rotor and a corresponding mark on the stator.
Assuming you know how to use a degree wheel and a piston stop to find TDC. Align the dots as follows for each model.

250 - 52 degrees BTDC
350 - 47 degrees BTDC
450 - 36 degrees BTDC
bobnorton
860 GT / GTS
Posts: 279
Joined: Wed Jan 16, 2008 2:18 am
Location: bromley kent

Post by bobnorton »

52 degrees advance? I don't think so, If you could start it the big end would soon knock out. Fully advanced about 40 is about the max I would think .
maelstrom
Cucciolo - the Lil Pup
Posts: 13
Joined: Thu Sep 08, 2011 2:42 am

advance?

Post by maelstrom »

I did not use the word advance.

I was working as a mechanic on Ducati motorcycles, when these models were produced. At that time there was no information available on the electronic ignitions. This information was supplied to me by the factory in response to a telegram that I sent to them. This was my chosen method of verifying such details as quite often the information was unavailable or incorrect. To be pedantic, I am sure you are aware that the same ignition parts are used on the electronic ignition singles, but the timing gear is one tooth out on the smaller models, hence the discrepancy.
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