New

Original Amal TT/RN/GP Main Jets - Flat Hex Racing Type - All Sizes (Petrol and Alchohol)

Product no.: 0901 TT/RN_Orig
from £4.50
Recommended Retail Price, plus delivery


These are genuine (old stock) Amal main jets of the type originally supplied for Amal TT/RN/GP racing carburettors.

They are easily identifiable as being the original racing Amal TT/RN type - because the hex part of the jet is uninterupted along its entire length, while the more common later Amal main jets (fitted to all road and competition carbs) had an indented section 2/3 along the jet, which is where the size is stamped.

On these earlier racing jets the main jet size is stamped in slightly larger numerals along one edge of the hex, as can be seen in the accompanyning photographs.  Many of these jets are in the much larger sizes only fitted to racing carbs.  It should be noted, that the later indented type can be fitted to Amal TT, RN and GP carburettors (and jet size should be the same calibration for both) - but out of preference, many people like to fit these original racing jets if available 

As well as the original TT/RN (straight hex) jets, in the same collection were a number of original Amal main jets of the later 'indented hex' design, which were manufactured later for all carb types - including Monobloc and Concentric.  These jets are original Amal (I would between 30 - 50 years old), but similar to the type available new today which we also sell - Item 0153.  Again, the table below shows this 3rd type of original Amal jet (0901_3) - state which size when ordering. All jets of this type are interchangeable with the original 'straight hex' racing type, and there are actually some very small sizes - going down to a very small 050 size.

 

Price is for a single jet, please state which size you require in the comment section when placing order. 

 

We have sub-divided the jets into 3 types:

0901_1 : Original RN/TT 'Straight hex' type: Size from 280 - 640 (mainly petrol)

0901_2 : Original RN/TT 'Straight hex' type: Size from 650 - 1900 (mainly alchohol/methanol. 

0901_3 : Original later Amal 'Indented hex' type: Various Sizes - see table below.  

The larger TT/RN jets are slightly more expensive due to their rarity.  

A Table of all available jet sizes is shown at the bottom of this listing (but apologies if not not kept fully up to date as jets sell).

Background on these jets:  A short time ago I was fortunate to be offered this large collection of original main jets from an ex-racer who was clearly serious about setting his carburettors up correctly (I know he raced both Manx and Gold Star models) - as the collecton was kept in a large box, split into sub-sections by jet size, ranging from approximately 280 up to the largest methanol/alchohol sizes.

All jets are in good original, unmolested condition - and some have clearly never been fitted (i.e. New Old Stock), because they still have the original wire/lead spot they were supplied with when new.  

If you are setting up a TT, RN or GP carburettor it is always a good idea to keep a selection of jets of various sizes - so that you can vary the jetting, to get the ideal jet for your state of tune/fuel.  Doing any form of engine tuning, changing fuel (or even ambient track temperature on a finely tuned engine) can make a difference.  If you are not sure how to tune your Amal racing carburettor for the correct Main Jet/Needle Jet/Slide/Needle settings, then in our Facsimile/Catalog section we offer a facsimile that includes original Amal information how to do this.

As a general rule of thumb - I have found that most competition bikes using Amal TT/RN on petrol tend to use main jet sizes up to a @ 650 main jet (dependent on cc/state of tune), while those bikes running on methanol or alchohol use much bigger jets from 550 all the way up to a (massive) 1900.  These original larger jets are now very uncommon to find - and once these are gone I doubt I will be offering any more!

Table of Jet Sizes Available:

Item Description Jet Size No in Stock
0901_1 Original Amal TT/RN Type (350-640) 350 1
    370 1
    380 1
    410 4
    420 2
    430 2
    450 4
    460 4
    470 4
    480 4
    490 4
    500 4
    510 4
    520 4
    530 4
    540 4
    550 4
    560 4
    570 4
    580 4
    590 4
    600 4
    610 4
    620 4
    630 4
    640 4
       
0901_2 Original Amal TT/RN Type (650-1900) 650 4
    660 4
    670 4
    680 4
    690 4
    700 3
    720 3
    740 3
    750 3
    760 3
    780 3
    800 3
    900 4
    910 1
    920 4
    940 4
    950 3
    960 4
    980 4
    1000 4
    1050 2
    1100 3
    1200 3
    1300 3
    1400 4
    1500 4
    1600 4
    1700 3
    1800 1
  (this size avail in indented - see below) 1900  
       
0901_3 Original Amal - later 'indented' type.  All sizes 50 1
    55 1
    150 1
    190 1
    210 1
    260 2
    270 1
    290 1
    300 1
    310 3
    320 2
    330 1
    340 1
    350 1
    360 3
    390 2
    400 1
    420 1
    450 1
  (alchohol jet - but later indented type - fits TT) 1100 1
  (alchohol jet - but later indented type - fits TT) 1200 1
  (alchohol jet - but later indented type - fits TT) 1700 1
  (alchohol jet - but later indented type - fits TT) 1900 1
       

 

Browse these categories as well: 2.a Parts to fit: Amal TT (and some 276/289) Carburettor, 2.b Parts to fit: Amal Remote Needle (RN) Carburettor, 2.c Parts to fit: Amal GP Carburettor