I am trying to ID a newly obtained dominator. Engine number is
C7600, Chassis 95988 with 99 stamped below. Is this a 500 or
650? What is oil grade and quantity for front forks? thanks
for any help

I think you have a mix. Look at :


http://britishspares.com/technical/numbers/nortonnumbers.htm

C means 1948. 

The engine number is about right. Year end 1947 was 7756. Year
end 1948 was 13792. I think these numbers go August to august
being the end of their season.

The frame is much latter. Is it a featherbed because they did
not have these in 1948 ? It is probably a slim line
featherbed.

The number looks like 1961 or 1962.

99 means a 600 cc. 1956 to 1962 - but since the frame is not
matching your motor is probably but not certainly a
500.(Someone may have changed the 500 barrels to 600) 

So I think you probaly have a 1948 500 cc motor in a 1961/62
600c featherbed slimline frame.


The NOC site is a good place for history

http://www.nortonownersclub.org/
Cheers

John 

That engine number is much too low to be a valid factory
number for a Norton twin engine ?. Is there a digit missing ? 
Is the C a G ??  Norton twins didn't come out until 1949. And
didn't have alternators until circa 1958, does it have an alt
or genny ? Alloy heads didn't appear until 1955, does it have
an alloy or iron head ?

And even the frame number sounds not quite right, featherbeds
have horizontal year and model codes, and vertical numbers,
and shouldn't mention that it is a 99. Sounds like somewhere
in there is a 600cc Dominator featherbed twin ?

opethiselps.

Second thoughts- Is this bike actually a featherbed twin ?

You don't have one of those later hybrid Matchless framed
thingys with a Norton engine in it, or the reverse ?  Or one
of the swingarm Norton frames thats not a featherbed ? That
could explain some of the odd numbers quoted...

Any chance of a pic ? - that would identify it in an
instant...

Sounding like a mystery bike. Thanks for your help. I will
again check all numbers. How can I get a picture to you?

Have looked at britspares numbers and another source but
cannot make sense. I will check numbers again and try and get
macro shot. Sounding like a real mystery bike. And its been
raining nortons where I am, having just picked up another
rarity pre war. Will post numbers tommorow. Thanks for your
help. Unfortunately I cannot figure out how to get photos
through to you good people. By the way the bikes are in
Indonesia.