Legend TT Air Filter issues-Fluffy Throttle Response

it is correct that you cant buy a filter,only the complete airbox from triumph and they cost £42 plus vat at Fowlers and £53 at W.O.T.
I know lots of people use k and n on their trident/trophy/sprint etc ( same engine basically as yours),not sure about rejetting, wouldnt think it would make much difference tbh. If I were you i would buy a k and n and put it into the airbox, it has to be better than the one you had in already. If the box is made similar to the Sprint one the screws usually break the threaded inserts and you end up botching it back together in some way,be that glue or self tappers. My bike has a standard new airbox so i cannot say for def, maybe others in here will know better. The original airbox on my bike had what looked like a nest inside it,no wonder it used to run rough,too rich.
I will also say I had a CB500 and changed to a k and n ,never needed to rejet that bike.

 

Been running K&N filter in my Trident for years. No re-jetting needed on mine with either original or aftermarket silencers.
Good idea to go down that route as removing the air filter is a right royal pain in the arse, as you have just found out! A K&N (or similar) is pretty much a 'fit and forget' option.
Be careful with the plastic airbox as the plastic is brittle and easily damaged.
At the last service, the mechanic (bless him) actually got the filter element out and cleaned it. I had wondered why he was sitting curled up in a corner of the workshop rocking gently back and forth while making low moaning noises when I went to collect the bike. Seems he is okay now!

 

Oh no - not the airbox removal nightmare again!
I've just broken out in a sweat and I've sold the Trident now!

 

It is - US bikes only

 

I think you may have just answered your own question. 'Not for road use' = non standard i.e. loud - usually! Check that there are no leaks throughout the system as this could cause popping. Also check there are no leaks on the inlet rubbers while you are at it. Usual trick there is to have the engine ticking over and spray 'easy start' over each rubber individually (or as near as possible allowing for overspray). If the revs rise when you do it there is a leak on that rubber. If not then all is well. Apparently/allegedly WD40 also works for this test.
As the bike hasn't been used much recently, stick some Redex or other similar carb/fuel system cleaner in the petrol to help clean out the gunge that is quite probably lurking in your carbs. Works well on my Trident which has been suffering from lack of use for the last few years due to my health issues, and previously when off the road over winter. Too old now for ice, freezing fog and 6" deep snow (me, not the bike!). Could also add horizontal rain on Rannoch Moor, but that was summer in Scotland!!

 

Check as much as possible but only alter one setting at once so that you know what effect each alteration has.
Sometimes a different grade of plug can make all the difference needed (colder plug if running weak, hotter plug if a bit rich - but this may well be cheating a bit!).
I'm not too sure if this is the case but the middle carb may have slightly different (larger) jets compared to the two outer ones to compensate/allow for the middle cylinder running a bit hotter. With less restrictive exhausts and air filter fitted, bigger jets could be needed, although my Trident coped easily with both mods (though I have now gone back to standard exhausts - just for a change you understand. May yet change back again!).

 

Fingers crossed then .......