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Static timing a 200GT

Posted: Wed Apr 24, 2024 3:05 pm
by mrkprsn
Hi Peeps,

A couple of days ago my bike wouldn't start. It would cough but that's it. I checked the usual (spark, valves, etc.). Everything looked good. I had never timed the bike myself so I figured let's make sure that is correct.

So I set up the timing wheel using a wheel I bought (could have made), a plastic spoon, a little glue, some tape and a 8mm bolt (see below). I have a 200GT. As far as I can tell there are no service manuals for this model. I have been using a 250 manual for most things. In there the 250GT has a static advance of 5-8 degrees. So I set the timing to that spec.

Recently I ordered some parts from Lacey and they also had a 125-200 (Elite, TS, SS, SCR but not GT) service manual for sale so I bought it. In there all the 200's have a static advance of 18-21 degrees. Do you think the 200GT will also have the same timing specs as the other 200's?

If so then the full advance would be 18-21 degrees plus 28 degrees for the automatic advance for a total of 46-49 degrees. That would put my point plate at the end of the adjustment slot. Does this seem correct to you? Thanks...Mark

PXL_20240423_213037208_1131x1508_500.jpg

Re: Static timing a 200GT

Posted: Wed Apr 24, 2024 10:39 pm
by Jordan
That's a novel way to use a timing disc, which is usually arranged to turn with the crankshaft.

46 to 49 degrees total advance seems very high, but I don't have experience with 200s so it could be correct.
When you say all 200s have a static advance of 18-21 degrees, do you mean with no adv/ret device, or with an adv/ret unit but with engine stationary?

Re: Static timing a 200GT

Posted: Thu Apr 25, 2024 10:56 am
by Ventodue
Hi Mark

Hopefully you've already found your answer from the postings to the Facebook group ;) . But if not ...

Here's the relevant page from "Ignition and Flywheel Specifications". As you can see:

Static advance up to engine number 157.411: 18-21°

Then BIG change from engine number 157.412: 5-8°. I don't know why the difference; hopefully others will.

TOTAL advance for early engines: 46-49°.
TOTAL advance for later engines: 33-36°

HTH

200 ignition.jpg

Re: Static timing a 200GT

Posted: Thu Apr 25, 2024 2:31 pm
by mrkprsn
Hi Jordan, I timed the bike without advancing the advance mechanism. I found TDC and then rotated the crankshaft back 20 degrees. Then I set the point plate where the points were just opening using a really thin feeler gauge and it started right up. The setting is right at the end of the point plate slot so for all the 200 owners out there just adjust your point plate all the way clockwise and you should be set. Thanks, Mark

Hi HTH, That page is exactly what I was looking for!!!! There is almost no documentation on the GT let alone anything that shows that the engine did change during the production run. I have an early GT # 156385. Another Ducati mystery solved. Thanks, Mark

Re: Static timing a 200GT

Posted: Fri Apr 26, 2024 8:07 am
by Jordan
That is a useful and interesting ignition timing chart that HTH posted.
It confirms that the timing for some 200s is indeed 49 deg fully advanced.
That could be some kind of record.

Re: Static timing a 200GT

Posted: Fri Apr 26, 2024 8:43 am
by Duccout
I'd be reluctant to follow that advice! Something lost in translation somewhere.



Cheers,

Colin

Re: Static timing a 200GT

Posted: Fri Apr 26, 2024 9:24 am
by DBDBrian
Plus one to that Colin, It seems a great deal of advance to me ?

Re: Static timing a 200GT

Posted: Fri Apr 26, 2024 12:21 pm
by blethermaskite
If that's the correct ignition timing?? it's no wonder back in the day the big ends didn't last too long!
Cheers,
George

Re: Static timing a 200GT

Posted: Fri Apr 26, 2024 6:42 pm
by ranton_rambler
My slightly non-standard 175 is set to 20 degrees BTDC static. I have a higher compression piston so timed it using the values for 175 Sport in the factory manual that I have. I have subsequently experimented with different settings on road tests and the factory settings worked best!

Re: Static timing a 200GT

Posted: Sat Apr 27, 2024 5:44 am
by Bevel bob
My Narrow case Mark 3 250 apparently should run 40 degrees , but i have never gone beyond 36 , Not had any big end issues.