Letting Your Bike Breath.

Probably not. Only thing gone on mine are the cans and I’ve fitted Motad ones which made it go like stink. The rest stays as it is.

 

I thought removing the intake snorkel was a popular mod and one which allowed better breathing with no other fuelling mods needed?

 

I removed the snorkels on our 1200's, wouldn't say it's any better/faster but sounds nice/faster on full throttle

 

The only thing not really needed is the secondary air injection system. (See Delboys garage on YouTube for how to do this and many other Bonneville mods).
Won't really gain anything by just removing this though if the bike is stock but useful in conjunction with other modifications.
I've removed mine along with the O2 sensors but I've also replaced the snorkel with a bell mouth intake, replaced stock filter with a DNA one and removed the air box baffle.
However, if you alter the induction side of the bike as much as this without a re-map then the engine will run too lean, especially if you go for after market pipes at some point.
I went with Triumph Twin Power's stage one induction kit in conjunction with TORS exhausts which gives around a 10bhp increase but more importantly more mid range torque.

 

Like most things in life folk tend to rush to what, who, how, when, where before establishing why? If ‘What’ you do is driven by a clear idea of ‘why’ you will not be disappointed by the outcome for your pennies.

The 790/865 Bonnies have a raft of gubbins designed to suppress undesired noise and emissions that inhibit performance out of all proportion to the modest benefits they achieve. Meanwhile your lawnmower gets away with murder! The bike is what it is and all the better for it. Aside from suspension tweaks, opening up the breathing gives you access to maybe an extra 15% of mid range torque stifled by ‘the gubbins’. That means appreciable improvements in tractability and pulling higher gears at lower rpm on gradients.

The airbox suppresses induction noise but you try running wearing a gas mask so..... remove the rubber snorkel and baffle. The paper filter is fine unless you ride in heavy rain. Your best option is the DNA filter.
Anyway, your budget will drive your choices from the menu

https://www.triumphtwinpower.com/bo...aster-efi-airbox-modification-removal-kit.php

Self evidently what goes in must come out so your planned exhaust mods balance the whole equation. Doing one end and not the other achieves no torque gains. That is WHY you need to do both or neither. I can’t speak for the efi tune but my fuel consumption on carbs is unchanged; unlike roll on acceleration and general drivability.

 

Sounds like the air injection system......silver stem with pipe adjacent the spark plug?

 

Removing the Air Intake System is a very easy job and there are videos showing how to do it.

Not a fan of Delboy, but this video does the job (I think its easier and safer to fully remove the tank):


This is the kit I used for AIS removal: https://www.squaredeals-ltd.co.uk/t...pass-carb--efi-models-bc1002-006r-38310-p.asp (also available in black)

When I first got my Bonneville I had an idea as to how I wanted it to look, and that included short cone silencers (purely for aesthetics), with the exhaust change an increase in jet size was recommended. So I got the silencers and rejetted, and at the same time fitted a K&N filter. I noticed the performance improvement immediately, the bike was more free reving with improved throttle response. Anyway I later changed my mind on the look I wanted for the Bonneville, and I was finding the short cones too loud, so I swapped back to the stock silencers. Immediately the bike just felt restrained again, so I then purchased the Vickers silencers and the performance was improved again.

I would certainly recommend making some tweeks. A couple of relatively simple changes can make a big difference, not necessarily to increase speed, but significantly improve the way the bike performs. Initially I was just trying to change the look of my Bonneville, but the combined simple changes of silencers, rejetting and air filter made a significant improvement to the way the bike runs.

 

my bonnie is still under 3 months dealer warranty (it is a second hand 2007 carb 865) so not made any changes yet, but the SAIS system will be the first thing to go and some slightly more rorty pipes would be nice, which seems to involve opening up the air flow and rejetting, some time next year