Amal 10TT9 1' 3/16'

[pete3000]

Hi everyone,

I have bought recently a magazine with a very good article on a RGS Taylor Dow and notice that the owner
fit to his bike an amal  10TT9 1' 3/16 (30mm).
I have in in my garage an original 10TT9 1' 3/16 carb that I've bought some years ago for another project but never use it.
I'm actually runing on a RRGS, and I was wondering if I could fit this type of carb on my bike. I actually have a 389 monobloc 1' 1/8
Does anyone has this type of carb fitted ? If so, what would be the jet sizes (needle - main) , throttle cut away number and needle number  ?
Many thanks for your answers.

[Rocket Racer]

Pete,
my road rocket is running a pair of these size, am running 1000 main jets (on methanol) so settings not much use to you.
Depends a lot on your engine spec and intended use. The 10TT9 certainly look good being a pukka racing carb, so a nice fashion statement if nothing else.
The TT do tend to need bigger main jets than the equivalent concentric/remote float carb.

What does it have in it jet and slide wise?
Tim

[Brian]

I am not familiar with these particular carbies but the Amal catalogue lists the following.

The 1955-56-57 Road Rockets use a T10TT9 carby, but in 1 1/16". They have a 340 main jet, 6 slide with the needle in position 4 and a .109 needle jet. The bowl is a 15 degree unit.

[Rocket Racer]

that sounds about right, I was thinking about a 350 main...
I'm running no6 slides.
The 10TT9 doesnt have an idle screw, so the idle is set off the throttle cable.
Carb parts (replacement slides) are comparatively expensive.
If you have a correct working carb at present I personally wouldn't bother unless your existing carb is worn out.
Bowl angle is important, must be 15 deg

[pete3000]

Thanks Tim and Brian for your nice replies.
My actual carb has the following specifications and works quite good :
Needle jet 30
Main jet 400
Cut away : 3 1/2
My engine specifications :
72mm Wiseco pistons 9:1
357 camshaft
Big inlet valves
Polished con rods
It has been totally rebuilt by SRM

The bike runs good (notice that the spark plug are a bit black), suppose my main jet is a bit too big , but
the specifications are the ones given by Amal. Also, after 4500 RPM, I notice that the engine takes less fast RPM's. 
I plan to use the bike on race tracks and I was wondering if the TT carb would be more appropriate than the Monobloc.

Pete

[andy2565]

i think when there is a single tt carb fitted the choke was on the right side of the carb and the 15 degree float bowl on the left,these seem to be a bit rarer,cant comment on running wise as i havent got that far yet,the main problem seems to be the idle being adjusted from the throttle.andy

[Rocket Racer]

Pete,
 seeing you mention use on race tracks, I would say that your bike should stand the 10TT9 you've got, 29mm might be better but the 30mm will be comparable.
The bigger carb will certainly help you above 7000.
Note: You will only get benefits from the bigger carb if you have the throttle wide open and intend to keep it there, anything less than full throttle you will get no performance benefit.
If you're just going for the odd track day, and not flat out, personally I wouldn't bother.

Tim