what carb

[paul]

Hi I am A new member and like many other members have stubbled over this forum when trying to find out info on my 59 super rocket, so hello all, and here goes with my first question.
I have found that my bike has a 67-1549 head wich i believe is a larger valve head than earlier models. what i would like to find out is wether i have the right carb to go with it the carb thats on the bike at present is a amal monobloc but the only numbers i can find on it are K33? I cant find any information with these numbers. can someone please let me know what carb should be on my bike and may be how to idenify a 376 carb from a 389 please help its driving mimad
many thanks  paul

[beezalex]

The carb type shold be stamped on the flange.  It should definitely be a 389.  The only significant difference between the small-valve and the big-valve carbs is the bore size.  Small-valve heads used a 1-1/8" bore (stamped 389/48) while the big-valve version use a 1-5/32 carb (stamped 389/47), though putting a 1-1/8 carb on a big-valve head won't hurt a thing...in fact it will be a little more tractable on the road.

[bl**dydrivers]

I would have thought it should have a 389/46 and the 389/47 was for the spitfire

[chaterlea25]

HI Paul, Alex,

I have two 1549 heads here, One I recently bought on Ebay from USA has a 1 and1/8in. inlet and the other I got in UK has a 1 and 3/16in. inlet
I am not sure what this signifies as both heads look original and not mucked around?

Paul whats important is that the carb is not too big for the inlet causing a step at the joint which will affect carburation
If the carb is the right size and working OK dont lose any sleep over it!

HTH
John O R

[trevinoz]

Paul,
            Measure the bore.
You could take the top off and have a look at the top of the jet block.The size is embossed on it.
Trev.

[paul]

Thanks for all the info, i am taking the carb off today, so i may be back later with more questions!
There are definatley no other numbers on the carb flange only K33, but when i get it off i will see what components are inside, this will probablly help with the indenification, more later.                                cheers again, paul

[paul]

Hello again, right ive got the carb off the bike so here goes, it seems to be a 376 carb as it is stamped on the throttle valve here is the spec:
376 with an 1 1/16 outlet
main jet 240
needle jet 106
throttle valve 3 1/2
pilot jet 25

It seems to be correct for a standard type head but perhaps not for a 1549?
The diameter of the inlet manifold is as best i can measure is 1 1/8 sligtly bigger than the outlet on the carb.
Can any of you experienced rocket owners give me a clue to the right spec.
Cheers all, paul

[trevinoz]

Paul,
           To be correct you should have a 1 5/32" Monobloc which will be a 389.
Home market has :-  Main jet  420
                             Slide      3
                             Pilot jet  25
                             Needle jet  .106
                             Needle pos 2

All subject to change to suit you.
  Trev.

[paul]

Thanks Trev, your obviously a fountain of knowledge on beesa thanks mate.
seems like an ebay listing is on the cards.

[brackenfel]

As an aside I've got my carb off at the moment (1961 Flash) & that's a 389/45 !! Measures approx 1 1/8 ish.. (my calipers are cheap & the carb mouth isn't quite round!)

Looks like Amal just used any number in that range at the time !! 

Adrian

[trevinoz]

Adrian,
                Look at the top of the jet block. The carby size should be there.
   Trev.