introduction and first question

[kalli]

hello all,

i have been around motorcycles for most of my life and i own a variety of classic bikes a lot of italians especially guzzis.
i have recently equired a 350 scrambler that has been standing for ever and i have been slowly disasemblying it in order to do a sympathetic ressurection that hopefully will not turn into a full restoration. i am competant enough to carry out the task and have been lurking for a while and learned a lot from all your posts.
of course i have questions but would like to know how to go about it, do i ask the all in our post or make specific posts per subect?
my 350 scr is a Wc 1st series build between 1969 and 1973, or so i gathered from my research

- is there any way to tell the exact year ? ( i have been on the online register and it falls between 1972-1973).
- is there a way to tell the size of my crankpin whithout splitting the crancases?
- my Crank gear (the one on top of the flywheel) spins but will not come off, it sort of moves towards the outside by a few mm but then it want come off, is there a woodraft key that should stop it spin? is this comon problem and how do i get it off without damage.

have to say that going through the site has taught me a lot

thank you for your help in advance
kalli

[single-junk]

The left front fork should have a date stamped into the slot that fits into the wheel hub.. another member here pointed me in that direction, and that's how (among other thing.. engine stamp, frame stamp) I came to pinpoint my 250 monza to be a 66.

[amartina75]

That's only true for the 31.5mm forks, the 35mm Marzocchi forks are not stamped.
Welcome to the forum, can you post a picture of your Scrambler so we can have a look at what you have.

[kalli]

hi there,
to save you the trouble it has
- Smiths instruments
- Aprilia headlight switch
- Aprilia headlamp rim
- VHB 29AD CARB
- Rev counter drive of the head
- Marzochi forks 35 mm
- Marzochi rear shocks,aftermarket
- Valve lifter
- Steel rims 19/18 radaelli
- single front brake hub
- bottom fork yoke black steel
- black headlight Supports
but still cant tell the exact year

SAM_0020 (2).jpg

[ducwiz]

Hi,

this picture from the Scrambler parts list (stored her on motoscrubs) shows all parts around the crackshaft. As you can see, in fact there is a woodruff key. Yours seems to be sheared off, because the primary gear can be rotated (against the crankshaft?). Was the big nut loose, when you opened the primary cover?
A sharp-edged two-arm puller may be used to get that gear separated. Some damage may be unavoidable, but will possibly minimized by aligning the notches in gear and shaft before starting the puller action.

Afaik, by measuring the width of the con rod's big end the crank pin version can be identified:
big end width = 22 mm -> crank pin dia. = 35mm, big end width = 20 mm -> crank pin dia. = 32mm
So you only have to remove head, cylinder and piston.

Sorry, but I have no information about relations between year of mfg. and engine/chassis no.

good luck Hans

[amartina75]

http://bevelheaven.com/data-single.htm
Look here for a list of engine/frame numbers for an idea of when yours was made. I think there is another better list somewhere but I can't remember where. There are members on this site that can give you a better idea of when your scrambler was made. Since your bike looks to be totally original, that helps with identification.
http://www.ducatiscrambler.com/
This link could be good for you since you are close, maybe shipping wouldn't be too bad. Shipping to the US is pretty high from Italy.

[kalli]

good information all around,

the nut was tight. looks like the woodraft key has sheared and traped it self in the tunnel that runs around the inside of the gear. it spins almost full circle and moves in a out but thats it.
can you tell me where is the woodruft key cut out on the crank so i can try and align it, i can not tell with the gear on. is it in line with cut out on the end of the crank?

by measuring the width of the con rod's big end the crank pin version can be identified: big end width = 22 mm -> crank pin dia. = 35mm, big end width = 20 mm -> crank pin dia. = 32mm

had a measure of the conrod big end width (just the conrod not the thrust washers), can not really get in there to measure accuretly, but it is about 18mm > 18.2mm. is that possible and what is my crank pin sixe then 30mm?

amartina75 thanks for the amici link, i am aware of them , they have a lot of parts in resonable prices. what do you all think about the quality of their pistons and big end kits? the bike is for everyday use around town and taking to the hills and mountains.

yes it was very complete only few parts missing, problem was would not come apart but thats sorted now.

[graeme]

Hello, yes the key way is at TDC same line as the end slot.
Good luck with what you find, hopefully the taper is still good under the flywheel for you.

Graeme

[kalli]

i was under the impresion its straight, are we sure that it is tapered or not for a 350 scr ?

thanks graeme

[ducwiz]

No, the bore of the gear is cylindrical. That of the alternator rotor has a conical shape. The rotor can only be pulled off by a special tool, which has to be screwed onto the fine 60x1mm thread surrounding the rotor's steel center. Don't try a 2/3 arm puller, you will ruin your alternator.

hans