This is a replacement for Amal TT or RN bellmouth if you want to use the bike on the road and are concerned about ingestion of dirt or grit - which some people are, as the standard Amal TT/RN type bellmouth is open to the elements.
The inlet is CNC machined from the same alloy billets as the 'Short TT Bellmouth' (Item 0140A) we also offer, but in the case of this type - the outer curved lip of the original bellmouth is changed to a flange, allowing snug fit of a cone type filter.
The cone is a commercially available 'Pit Bike' filter with . It has a 'standard' short type TT/RN inlet tract and thread with a modern 'Pit Bike' cone type filter fitted. In some of the attached photographs the chrome of the cone filter looks blue - this is the plastic protective film supplied with the cones to protect the chrome and should be peeled off after fitting.
These are CNC machined and are available in two bore sizes: Standard Norton International 500cc size - 1 5/32", and also 1 3/16" bore size (which is another popular size in our normal TT/RN bellmouth range) and the largest normal bore size that original Amal TT and RN carbs were supplied with). State which size you require in the comments section when ordering.
FYI - I would expect that the bore size is far less critical on this type of bellmouth, i.e. in case you have a slightly smaller bore size, such as 1 3/32" etc. - Normally the bellmouths on Amal TT (and other competition) carbs were blended with the carb size exactly - to assure maximum efficiency at maximum racing speeds. For those fitting this type of bellmouth/filter . . . normally on the road, to offer some engine protection from grit etc - you should expect that this carb setup is no longer going to be suitable for maximum competition performance (and a level of re-jetting may be necessary anyway)
It should be noted that these filters (as fitted to pit bikes) look to be of the gauze and thin filer material type, and although good value - they are not the K&N washable paper filter type - which would make the unit far more expensive. However, if you wish to fit a K&N style filter yourself at a later stage - then I believe the RC-790 K&N Model is a likely fit (email to confirm details of bore etc if you are considering this) and should have the same fittings. Note though - when I checked retail prices of this model of filter in the UK, as part of making these units - I found the price of the filter alone in excess of the retail price of the entire unit shown here.
Fitting Instructions and Jetting:
Just as with normal bellmouths to fit original Amal TT or RN carbs, these bellmouths have a thread that screws into the main body and will also use the standard TT/RN lockring (so you should be able to use the one from your existing bellmouth, or we can supply seperately - Item 0142).
It goes without saying that - just as you would when fitting any original Amal TT or RN carburettor to your motorcycle for the first time - if fitting one of these filters, you should check the settings yourself to confirm if re-jetting is required (i.e. Main Jet or Pilot Jet) - as this can vary a great deal from one engine to another, and is also dependent on the condition of the original carburettor. We recommend following the normal procedure for tuning an Amal TT or RN carb to satisfy yourself it is correct - and re-jet as necessary. If you do not feel you have necessary experience or would not want to do this - then we recommend not purchasing this item and continue instead with the original open bellmouth
Your basket is empty.
